. . . _ . ..J... .39.. ....I........... ...}... 3..........fiu........................._......_.........u... ,..m....... c. .... ... .. . . I ..- ......o. ... «.... cu... ,PI. .... .I ...w‘: .... . . . 3n”......:..onb .. .. . . 01.... . ... . . ...? r .. . [.411’... . ,. .a...‘4fi$3. ...: .....Cn- 0.. .12. . ... O . .2. s“... . .20 . .4. o. .. . . . ... D. 9... . . ...: 7.21.. 1...... 0.. ... .... .... . - .0 ..I. . a: .1. . . ~ 1.8....‘099‘ . . .. .. ..1. .. . . ob: ..., .. . . , ‘o . . .. . .3 . ...-E. . .0 a . o 0.... . . ... ... .. .. . .. . . ... . 9... . . ....-.o‘. . ...-0.: .0 . 9",: IV... ...‘...0 .... Q. ....Q. .. fl .. p.330... .lo..v‘o..l I.vh..v.au..p. . co. '4 .. . . ,3 3.9.. .. 6...... . u . .. ...-0‘01 .... .I... .0... .n . .. . a...:.. I... . . O. _ \1’9’. In ..“a... ...”N .U.’.Q“.~ O , . . '9‘... 2...... c A . . . ...: 2 13.9... .....5? ... ..3 .432. ..a.. (J: ... ..«Jf... ... our... ... ...... . ... ...... ... 3.... o .... .9. ...... . ... . ... ... O. 2r.x~n.ls, . I ... m... . .... o . .vc . I . .... . ...... .o . . q. . . .. (4...... . . . . . on”. ... K:— .... ... ....1. a. . .0"... . . . . 3.0.... I. .o in . _ 0 ..J. .. I. .... ...uhq'; . 0‘: n ... . o .. . .. .. . s . .15.. . 3.0.... . 1.... . . . . 1...: .... .... al. ... . .. Tu.“ . . OI. .... .. .... .«o 3.... ... ..ou: :- 1.0 i=1"... ova to u. . . .33.. . ...... .CII..P.-Ou. o..- . Vo‘lan; .. .0 ...... ’ofn?‘r1..o ‘n.‘-II ... I a ...Q .11 ....-. . .. no. a '1’... ...... 1.3.? ...} ..I 0... .0.’.. . h . o. 2... . a... ... 3...... ...; a . .. . . u .. . . . - ... , .....‘Ilto‘ l I .... .v. ... u .0. ...... .5: . 1 9....-. . A5.3.... ... .. .. .—. ... .hoo..la.1.$ .0. .....L. I (.... .. .. ...»... .......:..-.. ......5 . . q l 01 D aarmv . .. 1 .. 0.1 0...... .. . 0". at . ......L. . . . . .. _. . . _ . I o. . .. ...... . . . . . . .7... ......th tunings. .. U... .N..... I... 3 ... . . .u..l...o...l...t 4. 7 .... . 2.. . . .4. .v. . n. G.- ..L ... . . on. no. . .... 5‘}... n. J .. . .. .c . . .. c 70...... . A. 0.. a 9...... v‘ .u‘ . . 20., .... In .... .. . - o . 2’. ..I. L 5 ‘.J..Q... . 10... ...-I... 2'..." . -..}...- . . . . ...... T I.» .. .. .93...‘ 0‘ .—.:. ...-on .I‘. . . ...! . . . . .93.... Jot! a. ... ...o. 0......; .....I . .. .. c .0. 9‘. .33. c . iv... JAiL..£A 3 o‘.a 3..." I . «wwwié .02.... .. i. ..zcofi’l. .. .Wo‘adnflhf: J...‘ i . .v o 5.4”“. ...”. V" Then“. .u.......... . ... I... .1... .... .... .. . 0.: ... . Q ”I vs. .... .... .4 . u l v. - t rite-0””: k . . _ . . .. '0‘. \I: 9' .....u.....n.!.8. . . ...‘ 2...”: o. ...? ... ”a. .0“ . ... ....Z.l.f8&u$..na 930.....9..~. ..p 0.x“... .. ....- ..ol...‘ .3... ...... A . ....3... .’~.......... ...n... . .W... ..Q. i... . ...-..."...o. . .... n he“: .n v . . . ...4}. .¢ ... .. g. n ... ... .... ....rhnbauin.‘ . .. ...“...hve .u . ...}...A». . .. . 9.. .... .... .. . ...di' . . . . . .. . c .. . . .. . .. .0 . J09 10...”: .01“. H. I. ...... ...! 3...... . .c . . . . . . l y . . . .. - . . . .. . . . "H". O a. “H..Ju-‘qutflh.ountnn.fio.tn1‘ a... .u c :1. o. I.- I‘... 0'0. (G 0. ...I. ...... .Ilh. . ...‘v' . ' . I O, I. .‘Q .0. c. 9.. a. . . ....o 0.. in. ....o-z... ...‘u Y. . u a. .. . I. .0 . o. I..... . . O .3 . .... ....-... 0001,10 3’... 3Q. ... 3‘, ...: 43.4. . .4}....Al .... u‘ ... . .. .5. ...... ...? .. in”... .. . ...... . ...-”aunt”... . .. .. n .a .p.. {.11.}. . J’a’ ugh- .r..’ s .U .. c. (a... I f... . _ up”. .«u;b.$«h.swi..“’vgfizuu.«o ... . v. C... 3..,o o: .. . .o I . ... ...-.1. . 3 v. . .... ... ......a... . ...... .....lozif. ....luc. .33.... .....32... .00 “...-23”.)... \l‘. .... ..Jlr. . -5............. . 5.333.... .... .....ue. . ...": ... . .o I. .... I9... .2. ......o. . 0...... ... 5.0%.”.Hrhw 1. ...: . at... J 1.3. . . 1.9.7.11- 05"... .I‘. ... .1 ......K?‘. .7 . o 3.. . o . ....c 5... . .. , ......1...J‘..'Ie..¢n.: . .‘I... (- "u.. $7.... 11...... a . .. . . . 123...}: ‘c'5‘550c‘? ‘20...) ‘0 t 2.. . . . -.....5. .... . I . . . . . . . . . c . ... I .... O .) n .. . ...... “t. . . .. l....-..n. 1..."... 1.03:... ‘30... ....s 0...... .1...“ ...1 . . . . ....395.‘ ... 3.1V . .0..!...... . 0!.- JIJ... V . . . . . . . . 1f‘t".flnaoolc . v .... . I . 3. .... .I... a... 0.. .. ... .... .. 3?... .0... ... L30.u.0b...0 . . 2. .n .....I . .3.o,....ct . . . . v . on}; 0... :1...‘ :v .9.‘ . '1. ... ...-6‘“ .I. h. . .. .0...o.’§. ’33..... I" In. 3 . I .....§.. ..., ...: v ...... 602.931. . .I o Co v. ...." . Q o 50......2 no .. v. . ’50....0... . I .0 . . . .... ’ . ou’u . ’ , .00. .2 .u ..3.....i!c...o.3l .. . ... 3 .91.... .3." . ...! ......”‘m; .0 ‘I ..‘.o - .....va a I. (lull _ . . 3.3.9.1.. 3 ... .... .... ...: I... . ...!I... ... .. 0 . . . .'-I.¢’,‘ .I. . .. . . .. . . . , , . .wu“a1.ufl...)?..l . ..l.\..m...«v. .....mfl. . o . v n a . . . .TAII IO. 0.. . ...... 3.. .... . . ... L. . L}... 4fi9>i.o..~...,15 ......3‘ .9. . OfI‘vaz‘. .4... '1. I‘ ..D.»F 1 . . MK“) 3.... .‘|:.-O¥o‘.u. .. .... ’no... 3 ca.1\. ’5‘. o’I on O. ’0. .‘Oav .nrl . ...-o. . . o o u! a. .- . V ...-...a-ohu . . o. 40.. .10.)...3l . ‘ ... .... .9 I . .... . o . . c’ .... _ n .. . . . .\ .....f.....l.....:...‘.. n . . 3 533...... . 9'33.” .... .. . .m... 90.1.)...”- . (.....i ...J 553.3“ ..o..8.‘\8} . . ...? .. .‘. “ ..c. 71‘! .X’....uu 30.3“ .... t . 30.13... . ”Pa ..o. \l..... .30 .... ..Io. ....0‘..£...o. 0.0... l . .. 1.: 3:33....) 0‘ . V n I ._’h 0.. '0 ... i...’ ...! wash}... "..."... ......Q... 0. ... .. . . ..v . . I ...._......... “v.35... ,. . n. . . ... . . . . . 1.533.... .. . . ...I..r.l..llo.. ...! I .02.... ...... .... . ... . .o ....I-.. . .....0... . . , ... , . 1 . .. . . ...... .... \r...’ii.t:. (I . v.31!!! .....l. .. ... o . 0...... . . . . ‘ .- ... ......mfos a. n . . . .0 .... IO. . in . 1... o. . ... . . 4 o . .9... v. 5.. 5.‘0 .. . r5... .. .. ......» s. .....uufiflufi . .i?..«....:. I: .... . ..a u... ... ... ... 0.. . 4.... o . . ulna. J . i. J. 0" . 11......0. 7. i ......loa.d.~..\t v . . ....9¢.nbv..v..c..... .. 1. . .. I". . v. 1... v). . . I... . ... . . - ... o .0...’ .0 .leOv...... 0.. .. «.... .. . - . 9.“... v ., ... . o' . - . . ...... ... 1.11 ... . .. .. . . 5.. . ...... . ‘5. I . . .10 o. L... .8 . Jr. . . .. .0. ..ll‘...... . no!) .0 .2. ..5 ... ... ”8‘5 0". ‘33... 0 ._.u..u......._.........«. an»...g..,}.......... ...... AD. I. . . 52s ’ h I . I ....c 3.....‘1’5’.‘~.§.‘A . 2 3m . _ 0.... 1 ‘ ‘...a....0. o.).-... 919.1,“ .. ‘.. 5v. .1. . 5.?‘1’...£¢.|b. ...Q. Ill...l.‘b .02... . t. . . . . . .i .:..‘.....li!..!o.uo.. .035 a! ......o! .... ... a)... . ..X .9? . .u'h.u.m..... . . .‘vd‘...§tt.!.r33..i. l 3.4.... .I... .’.. . . ...... ....) .. .. . . . . . ’ ’3... I... ... . . .....n.,.lk. 0.. .5. v 03.. ... . ... ... o ..5. o . .. .\.~. ‘15....) .‘ ‘31: .O‘ I ll. 9...... ... . . .. . .4. ...o”.u)..’. ...-... .... O. ..X..p..... ....‘o. .06.... ... .... 3.." ....‘Av . ...:.v." .1... . tit-o... 0.5... .. ..., .u . I Y“. o 11.. '8‘: ...»...olt. . ..luwh .3001! o. I... 0.1 .. ... 0‘ ... .0 w... .n J’... a. ‘3' . ... .... .... t a... I . 0.9:.- I ..l-, v . .H.3I..m .. ..n. . 1...... 3- I... . (Stag-5:... .....Olauzll... n. ......K ......laacur 11?;7? - - t7}. -‘~ c". oIr C ;‘ I. .....Q. .1. . . via-‘r'dnur. . A ls. . . .. . . ......l. .1 .3133... {...i.‘ .. . 3-...) ..3 ....‘on... .... ... ..‘v .vlvo. ’ J.v.b.‘ I o 5 . . . c 5......0. Q. ....1. ....a ‘1 . . . . . I. . . . u ‘l. .. to ‘u..l. .._ u ..v’tn..-....u~. .‘ 0."... . . .v. .... .MH..Htl.-... v0. ‘3 ‘04 .9 ......tI. ......oa. . ... . .- .( . ...... .9 a .‘50. ... ... Q. . . .... .I . Q... . 31. .. 2 3!. 9.1.1.1.»... . I. . O. v. -..-...... .o '3'. . o .0... . ‘ ...-9...... . ... .00.... ..o’. . o. . .I. . (o Ki... ‘r'fi . [.00 Q...) .0. ...-........ ...... .. .. . . t" I I .lu‘t ...! .... a .9 _. ......a..‘oo.§...u.... 5...... 2.3.5.; . .....J.....f.. . .... o. .. . 2. 1.. ...‘.Q."Il.,, ... ......l....l.- f. ...o on . ...! o. . ‘xli ... u '3 I...‘ ug‘.’ o...0......u .3ov .. .. . I\ \‘10. .0 .3". .... o... ... I .... .... ..g... .11.- . . . .I?’.. n‘. . ...-15.. . v . .... .’l.. . .01.... .....Jinoa. . . . .O ....4 I... 0310. o 3’ . . .... ......n. 0....v-na— . .0..- .- .. . . .' v’ . 33.44.. . ...‘i.......§....c~ ...... . ‘. ..Q ....5... I .271. i..-...... .....\ .... . .QO. v! 0.... .I 13,-. t 1.. . . ‘u ‘o‘... ...... (cs..‘uo ... .a .... ‘9‘: I... . - .. . .0... ' Z . .Q. 9...... .99....n...w. . . . ...,v‘...\ .. ,0 . v. .7 ...... a... 41......- . Q. .. ., u . .9.- . A...tv..0 .. .‘o. to...- . p03; .... . 0.... . 9... .... ...: . .... . . .... .15....o..... . .. - ...u. . . v . . ... ......ntl. ..‘Ouo-....¢t 1.... .. . . O. . . .o ... .....3... .. f...) .ln. . , . . . ......-..o_.. I. . . . . . . .. on, .I.... .. ...o . . . I . . ... . . . . ...... . _ . v. .. ...... ..Qr‘. mi. . .. . I”... ... .. I . .u u o .....u. . o . . . . . . . M . . $4.... :.?.)..0 '. I. . .. . ... L .0 {I ..q o . . - . . . ... .. l . u h . . . . o. I . .0 . p I . . . . . . .. . c v .. o . .... ~ . . . I ... . .. I o . ... O. . . 0 u . . . . . .. . .... . . .. .. . Q. ... . . .. . . .. . II: . . . .... .12.. . 9. . . , . o v . , I. .... . . . . . .. l... . ... .. . o . I . . . . . . . . . . . . . . u . . .n r . ... . o O . ... . . . .... . ...4 .... o . . 9 . .o ..HH...........“ . . $050.". ...¢ 0 .. .... . . . . . . . . . , . . . ... 11......5... .0 . ” ... .. .I.. . . ., . . . . . . . . ...... \:.II. . . o v . . . . .. . . . . . .. . . .... "u . . . . . . . . .. . . . . . . . . , . 1. .l. . . . . . . . . .. .. . . . . . . . .. . . O. . . . . . . . . .. Q...O . . . . ... . .. . .. . . .. . . . a 1 . . t "C . .c . . . . .. . . .... .... . u l. . . . O t ‘ ... . . .. .. . . .o . . . h... 14-...” ‘ a . . . . - . . . . . 3......t .09 o I . . . ~ o .- u n I: -v.. A . .... .... , . . I ._ . . . . . . ..... . . .. . .v.. . u .... .. .... Q. ... . c ...-5...}... x. _ v I. u . 22".. .. v . .... . .. .. .. . .... _ V. .. .. __ . .. .. . .. . .. .. ... ......1 . . 5... .I. w I . ...-.. 0.1 .8-.. ... .. ... I . ... ...: . . s . . .V. . v. .. . o. .. u! . - .0. . .. . . .... g . o .. ...-... .o .. .4 . . .... .. n .. 1.. o ....c .. uI. b.“ .) . ... .. . . . . \o .. .~ . ... . . v. .7. . .. .. .....a...l\0. : .. ‘Iroi..) ”a . .. .. ... . . I . u .o I . ... . . . . ... . u .. .. ... . -. ... . .‘II .0 O ..,. \C . . c. . . . . ... O. o .v ..v . . . ... I... .. . I .... ... .. . . . .. .. . "1"..- a. o . ... I . 1... ..II 0 I... .... .. .. . . . 3 . .. . . . ...t. . .. . . . . .. . . 1'... . . . . . . O . . 6 .u o. r. O . . . . I. -. . I. . . I.“ . . . a. . t . . . . o. . o u .. . .o n c I... . .. . ... 4.! ..v. .. .4 . A ... a . . I . . I t . w .. O c. .- I.) . . p I . fi. . no... .. . s. .. 1“. .L.O..c. I. . . u . .. . u. u . . . .. . . .0. . . L . . . . o . I . 0 . . . .. . .. .I .. . . o .0 .. . I ... . v .. . . ..I. ......l . ... ...! .0... .I . ... . . . _. .. ... . . l ... c s . .. I . V n . 4 . n . . O _. .I I I ... .. ......T“ 0.6... .- .., DA ... ... 1...".5.‘ .... u . . .... .... .. 1. .- . v . Q . a . ... I. .A O . . 1.. . o .. I .. . . .... .1 . d. ......T .. ~. .. . ..-. Q . . «I ... .5 .\¢/. u..\.lr' ‘33....“ 'I . I. .3 . . .. .. v . .0. . . ...... ..X. . . .. . . . o ._ .. . .... ._ . . 9. I I o . ...) .. .. . .. .. . - .... .. . d..&£. V..hh)..'l.1 .V .. O. . . . . . .. ... o . . . . . V... .- . ... . . ........ .... .. ... -. . s. . ....... v........ . O 050...... v. . . . ... I . . . o . . n. . .. . L . . .. I .. . _ . . .. .. . . .. . . ... ,. ... .. ... . 4. . ... s . . ..!.\. P... . . 5. \w. . ...: O. . . .I .. . I. .. . . -.. o. . . . ... . . . . ... I .. .... . c. .. .. A .. .. ... I. to... -. . . . .. . . ... ._ .. _ n' .. .. o . I ... .. . I. . .O I C. . .. Q. . .. J x ..I.. .. n. - . .. _ . .. . ... . . . . . .. . . a. u n . . _ . .w . p ._ . . . .0 O. I.. .. . I _ .. . . . n — . I01. n . .. . .. a I N . . V. .. ...... . . . . . .. . . .a o . . II o . . . . .... c I o . . . .. .. v. . A . . . .c c Q. .s ... a .. I \ . . pi . . I . a. . ... .. . . . I . .c . I .. I .... . .. . . . . . 4 o . . . Q . o o. . :I . o q n. o 4...? . . o . 'u I O . . . . . . . u . on. . . I 0"; I ' n o I v”. .. . . . . . - ‘ . . . . Q. J L .I ‘ . n I: . . .. . .. 3...»: ... . . 0‘ . I... ha. \|.O .. m . r . n . . "a. u... .9: .70.... S. . . . . .... . . ..4 ..«t I . I. ...? h w .... £2“... .03. n a calf .» ..mm: 2.0.33.3??? .. ..|.. ......M. .1 . .. ......a ...: a - .3, ... I I. . I . . . ... \ o. . .1 c}... ..t . .. a. 4 ... . ....3'n‘o 0.. t... .. ...: ’2... .. ..J 0.. I Q... 7. ...: .» I. I I . .§ .c- . I. . . o . ..I c... . ...... < . p . r v... .0 a. i. o-‘. .‘I.’ .0. oil. .5 .. . .I \l ...-D. X ... ... J: .... I... I .. I . . m... . . .. 5 D. :3... cl mg "3.011;...“ ”—9..“ .u..u.9“.“.‘ . ..m. a. 1...... .....I .- :5... ...w. .... .... c . I!’\~... . . q. .9... I... . .. bl. . .I. ..l .. , . . . . . . . . ...!2:.»..c.. ... no .. '1. . umbaw..u.o 0.. . . . Sfio ”...“.n . ......‘t. .O. ..N‘HD‘OZMW.) ¢"ux.".’fi 6 1.....01... inc-.... 1. .... .o 3.... ...}... ...... .09}; . .. 1...“. 7.1”...” 5.... ... .. .. . I . . o . . | \ . . no .. o... ’1 .. 9. .... ..l V. .. .. inc... 0. . ..v o v. . .. . , . .. . . I . . . v I.-. ...! ‘5 I .. I..As.| DIN! ‘6‘. V. ..T;. .2" O‘Th _. 3...“. . 0‘. ... .... . ‘cuu- ...... II. 1.. go... to". .. . .... .. ... ......z .... _ . . .. . . .... d o . . ...h. .4...q _ d . .....v‘ . .... I. b .... 7...!- . ......oo? . ...I o o. I II . . . .. . 30.4.2 .... .. n. o. . I .. A .. .. . 1 . . . TEA. LIBRARY 3 Michigan State 2 at, University This is to certify that the thesis entitled A RADIOGRAPHIC ASSESSMENT OF PEDIATRIC FRACTURE HEALING AND TIME SINCE INJURY presented by CHRISTINA A. MALONE has been accepted towards fulfillment of the requirements for the MS. degree in FORENSIC SCIENCE 7/Q WMW :/ /Major Professor’ 8 Signature //' 42 0 m/ Date MSU is an Affirmative Action/Equal Opportunity Employer PLACE IN RETURN BOX to remove this checkout from your record. TO AVOID FINES return on or before date due. MAY BE RECALLED with earlier due date if requested. DATE DUE DATE DUE DATE DUE 5108 KzlProj/Aoc8PrelelRC/DateDuerindd A RADIOGRAPHIC ASSESSMENT OF PEDIATRIC F RACTURE HEALING AND TIME SINCE INJURY By Christina A. Malone A THESIS Submitted to Michigan State University in partial fitlfillment of the requirements for the degree of MASTER OF SCIENCE Forensic Science 2008 ABSTRACT A RADIOGRAPHIC ASSESSMENT OF PEDIATRIC FRACTURE HEALING AND TIME SINCE INJURY By Christina A. Malone Although the physiological process of fracture healing has been well studied, there is little information available on the radiographic assessment of the rates of pediatric fracture healing. The aims of this thesis are to extrapolate data on fracture healing from radiographs, evaluate rates of fracture repair in young children, and compare how these rates vary with the age of the individual and the skeletal element involved. The schedule presented may enable forensic anthropologists or radiologists to supply information on the timing of injuries to radiographed remains that exhibit varying degrees of healing. This study examines 294 radiogaphs of tibial and radial fractures in 107 infants and young children. A series of stages were used to describe and measure the typical bone repair process for these individuals. The sample was segmented into age groups (0-1 years, 2-3 years, and 4-5 years) and fracture location (forearm and leg). The variation in fracture healing rates among age groups was examined using AN OVA with Bonferroni correction. The variation in fracture healing between the tibia and radius was determined using Welch’s t-test. The results determined that age affected the healing rate at the beginning and end of the healing process, with younger individuals healing at a faster rate. Fracture location influenced the healing rate at the beginning to middle of the healing process, with forearm fi'actures healing faster than leg fractures. ACKNOWLEDGEMENTS I would like to acknowledge my thesis committee, Dr. Sauer, Dr. Fenton and Dr. DeJong, for all their help and advice during the research and writing process of this thesis. Their input was invaluable, and my research was enhanced by their contributions. I would also like to thank Dr. Edward SIadek and Sabrina for their assistance in obtaining my sample. I would not have been able to complete this research without them. My fellow graduate students also deserve thanks. Their ideas and support have been priceless. I would also like to thank Tony for his words of encouragement along the way. Finally, I would like to thank my parents for their unconditional support throughout my struggles and accomplishments in my education and in life in general. iii TABLE OF CONTENTS LIST OF TABLES ....................................................................................... vi LIST OF FIGURES .................................................................................... ix CHAPTER 1 INTRODUCTION ..................................................................................... 1 CHAPTER 2 BACKGROUND — FRACTURE HEALING ..................................................... 6 CHAPTER 3 BACKGROUND — INFLUENCE OF AGE ..................................................... 14 Child Abuse .................................................................................. l9 Radiography of Pediatric Fractures ..................................................... 24 CHAPTER 4 BACKGROUND — INFLUENCE OF F RACTURE LOCATION ........................... 28 Forearm ...................................................................................... 28 Leg ............................................................................................ 29 CHAPTER 5 QUESTIONS AND HYPOTHESES ............................................................. 32 Specific Aims ................................................................................ 32 Hypotheses ................................................................................... 33 Expected Results ............................................................................ 35 CHAPTER 6 , MATERIALS AND METHODS ................................................................. 36 Materials ...................................................................................... 36 Methods ....................................................................................... 37 Statistical Analyses ..................................................................... . ..... 38 Stages .................................................................................... 38 Age ....................................................................................... 39 Fracture Location ...................................................................... 40 CHAPTER 7 RESULTS ........................................................................................... 42 Radiographic Atlas of Pediatric Fracture Healing ....................................... 42 Stage Analysis ................................................................................ 47 Age Analysis ................................................................................. 49 Fracture Location Analysis ................................................................. 53 iv TABLE OF CONTENTS CONTINUED CHAPTER 8 DISCUSSION ........................................................................................ 56 CHAPTER 9 CONCLUSION ...................................................................................... 63 APPENDICES Appendix A ........................................................................................... 67 Appendix B ........................................................................................... 78 BIBLIOGRAPHY .................................................................................... 98 LIST OF TABLES Table 1. Summary of Sample ..................................................................... 36 Table 2. Stages and Healing Times ............................................................... 47 Table 3. Analysis of Variance with Bonferroni Correction for Six Stages ............... 79 Table 4. Analysis of Variance with Bonferroni Correction for Three Age Groups with Six Stages: Stage 1 ................................................................................. 80 Table 5. Analysis of Variance for Three Age Groups with Six Stages: Stage 2 ........... 80 Table 6. Analysis of Variance with Bonferroni Correction for Three Age Groups with Six Stages: Stage 3 .................................................................................. 81 Table 7. Analysis of Variance with Bonferroni Correction for Three Age Groups with Six Stages: Stage 4 .................................................................................. 82 Table 8. Analysis of Variance with Bonferroni Correction for Three Age Groups with Six Stages: Stage 5-6 .............................................................................. 83 Table 9. Summary of Analysis of Variance for Three Age Groups with Six Stages and Mean Healing Times ............................................................................... 83 Table 10. Analysis of Variance with Bonferroni Correction for Three Age Groups with 3 Stages: Stages 1-2 ................................................................................... 84 Table 11. Analysis of Variance with Bonferroni Correction for Three Age Groups with 3 Stages: Stages 3-4 .................................................................................. 85 Table 12. Summary of Analysis of Variance for Three Age Groups with Three Stages and Mean Healing Times ......................................................................... 85 Table 13. Analysis of Variance with Bonferroni Correction for Three Age Groups with Two Stages: Stages 1-3 ............................................................................. 86 Table 14. Analysis of Variance with Bonferroni Correction for Three Age Groups with Two Stages: Stages 4-6 ............................................................................ 87 Table 15. Summary of Analysis of Variance for Three Age Groups with Two Stages and Mean Healing Times .............................................................................. 87 vi LIST OF TABLES CONTINUED Table 16. T-test for Two Age Groups with Six Stages: Stage 1 ............................. 88 Table 17. T-test for Two Age Groups with Six Stages: Stage 2 ............................. 88 Table 18. T-test for Two Age Groups with Six Stages: Stage 3 .............................. 88 Table 19. T-test for Two Age Groups with Six Stages: Stage 4 ............................. 89 Table 20. T-test for Two Age Groups with Six Stages: Stage 5 ............................. 89 Table 21. T-test for Two Age Groups with Six Stages: Stage 6 .............................. 89 Table 22. Summary of T-tests for Two Age Groups with Six Stages and Mean Healing Times ................................................................................................. 90 Table 23. T-test for Two Age Groups with Three Stages: Stages 1-2 ....................... 90 Table 24. T-test for Two Age Groups with Three Stages: Stages 3-4 ....................... 90 Table 25. T-test for Two Age Groups with Three Stages: Stages 5-6 ...................... 91 Table 26. Summary of T-tests for Two Age Groups with Three Stages and Mean Healing Times ................................................................................................ 91 Table 27. T—test for Two Age Groups with Two Stages: Stages 1-3 ........................ 91 Table 28. T-test for Two Age Groups with Two Stages: Stages 4-6 ........................ 92 Table 29. Summary of T-tests for Two Age Groups with Two Stages and Mean Healing Times ................................................................................................. 92 Table 30. T-test for Fracture Location with Six Stages: Stage 1 ............................ 92 Table 31. T-test for Fracture Location with Six Stages: Stage 2 ............................. 93 Table 32. T-test for Fracture Location with Six Stages: Stage 3 ............................. 93 Table 33. T-test for Fracture Location with Six Stages: Stage 4 ............................. 93 Table 34. T-test for Fracture Location with Six Stages: Stage 5 ............................ 94 vii LIST OF TABLES CONTINUED Table 35. T-test for Fracture Location with Six Stages: Stage 6 ............................ 94 Table 36. Summary of T-tests for Fracture Location with Six Stages and Mean Healing Times ................................................................................................. 94 Table 37. T-test for Fracture Location with Three Stages: Stages 1-2 ...................... 95 Table 38. T-test for Fracture Location with Three Stages: Stages 3-4 ...................... 95 Table 39. T-test for Fracture Location with Three Stages: Stages 5-6 ...................... 95 Table 40. Summary of T-tests for Fracture Location with Three Stages and Mean Healing Times ....................................................................................... 96 Table 41. T-test for Fracture Location with Two Stages: Stagesl -3 ......................... 96 Table 42. T-test for Fracture Location with Two Stages: Stages 4-6 ....................... 96 Table 43. Summary of T-tests for Fracture Location with Two Stages and Mean Healing Times ................................................................................................. 97 viii LIST OF FIGURES Figure 1. Fracture Event. Reproduced from Hufnagl (2005) .................................. 10 Figure 2. Granulation. Reproduced from Hufnagl (2005) ..................................... 11 Figure 3. Mature Callus. Reproduced from Hufnagl (2005) .................................. 11 Figure 4. Partial Bridging. Reproduced from Hufnagl (2005) ................................ 12 Figure 5. Almost Complete Bridging (tibia) and Complete Bridging (fibula). Reproduced from Hufnagl (2005) ................................................................................ 13 Figure 6. Individual #10: Forearm fracture, Stage 1, 0 days healing ......................... 42 Figure 7. Individual #10: Forearm fracture, Stage 1, 3 days healing ........................ 43 Figure 8. Individual #10: Forearm fracture, Stage 2, 17 days healing ....................... 43 Figure 9. Individual #10: Forearm fracture, Stage 3, 30 days healing ....................... 44 Figure 10. Individual #10: Forearm fracture, Stage 3, 46 days healing ...................... 44 Figure 11. Individual #107: Leg fracture, Stage 1, 6 days healing ........................... 45 Figure 12. Individual #107: Leg fracture, Stage 2, 11 days healing .......................... 45 Figure 13. Individual #107: Leg fracture, Stage 2, 28 days healing .......................... 46 Figure 14. Individual #107 : Leg fracture, Stage 3, 49 days healing ........................... 46 Figure 15. Individual #8: Age 1, Forearm fracture, 0 days healing ........................... 68 Figure 16. Individual #17: Age 4, Forearm fracture, 5 days healing ......................... 68 Figure 17. Individual #92: Age 1, Leg fracture, 1 day healing ............................... 69 Figure 18. Individual #109: Age 5, Leg fracture, 0 days healing ............................ 69 Figure 19. Individual #14: Age 4, Forearm fracture, 27 days healing ........................ 70 Figure 20. Individual #74: Age 1, Forearm fracture, 7 days healing ......................... 7O ix Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 Figure 31 Figure 32 Figure 33 LIST OF FIGURES CONTINUED . Individual #67: Age 2, Leg fracture, 54 days healing ............................ 71 . Individual #75: Age 5, Leg fracture, 39 days healing ............................ 71 . Individual #47: Age 5, Forearm fracture, 50 days healing ....................... 72 . Individual #86: Age 1, Forearm fracture, 75 days healing ....................... 72 . Individual #98: Age 3, Leg fracture, 42 days healing ............................ 73 . Individual #100: Age 5, Leg fracture, 40 days healing ........................... 73 . Individual #12: Age 3, Forearm fracture, 51 days healing ....................... 74 . Individual #35: Age 5, Forearm fi‘acture, 40 days healing ....................... 74 . Individual #26: Age 5, Leg fracture, 63 days healing ............................ 75 . Individual #7: Age 0, Forearm fracture, 49 days healing ......................... 76 . Individual #49: Age 3, Forearm fi'acture, 111 days healing ...................... 76 . Individual #40: Age 5, Forearm fracture, 418 days healing ...................... 77 . Individual #115: Age 2, Leg fracture, 188 days healing ......................... 77 CHAPTER 1: INTRODUCTION While once a relatively minor aspect of forensic anthropology, the assessment of trauma in forensic cases is of great importance when determining the injuries and physical abuse that may have occurred to an individual. One of the most significant aspects of such trauma is the timing of the reported injury with respect to death (Sauer 1998). Skeletal trauma can usually be differentiated among antemortem, perimortem, and postmortem. While perimortem trauma may be more crucial in the medico-legal death investigations, antemortem trauma, the focus of this study, can provide valuable information that may aid in the identification of an individual or in the history and timing of past traumatic events. Past trauma of an individual may be an indictor of future injury or cause of death. Additionally, the amount of healing indicated may be able to reveal if inaccuracies are present in the explanations or timing of questionable injuries. Therefore, the analysis of antemortem trauma and a complete understanding of the fiacture healing process may enable forensic anthropologists to apply information on the timing of injuries to skeletonized remains that exhibit some degree of healing. The occurrence of trauma before death is indicated by the presence of bone remodeling. When antemortem fractures occur, there is a schedule of the healing process, indicating what occurs within the bone after a certain amount of time. The manifestation of this healing implies that the individual’s tissue continued to live after the trauma. In adults, rates have been established for what can be expected for a normal healing process. The healing process consists of an inflammatory response to the injury, repair of the bone, and additionally remodeling and recontouring. As part of the healing process, a callus will form to strengthen the compromised injury site. Frost (1989) states that significant callus formation may take four to sixteen weeks to occur in adults. Sledzik and Kelley (ms) state that an osseous reaction of healing may be present in as few as seven days, with an average of thirteen days required to indicate healing when vieng dry skeletons. Therefore, any evidence of skeletal healing on dry-bone suggests that the injury in question occurred at least a week before death. Unfortunately, such a schedule is not fully understood for pediatric cases. As children are still in the formative phase of bone growth, healing of traumatized bone may occur at a faster rate (Hobbs 1989; Kempe et a1. 1962). Ogden suggests initial ossification may occur by 10 days after the injury (1984), while Patton generally states that healing in children occurs in half the time as healing in adults (1992). It has also been suggested that a periosteal reaction may be present in children within four days of the fracture event (Prosser et al 2005). Since these rates do vary between children and adults, the assessment of fracture healing in children at the time of death can only be made in very general terms. Even though the rates of healing are not well understood in pediatrics, such information is useful when assessing the timing of injuries and whether the trauma is consistent with the story presented. Through analyzing the timing of fractures, one may be able to demonstrate whether an accidental event occurred or intentional abuse caused the trauma. In the present study, radiographic stages are applied to the fracture healing rates in young children to determine a range of time-since-injury that would be consistent with the trauma. From the use of these radiographs, the age of young children and the location of the injury are examined as factors in the rate of the healing process. While radiologists can readily determine if a fracture is recent or older, radiologic dating of fractures in children is often considered an “inexact science” and the current methods available for this analysis are sparse (Prosser et a1 2005). Radiologists often base their estimates of the timing of injuries on their personal clinical experience, not on primary research. The concerns inherent in the radiographic dating of fractures demonstrate the “urgent need for research to validate the criteria used in the radiologic dating of fractures in children younger than 5 years” (Prosser et a1 2005:1282). While forensic anthropology cases normally center on skeletonized remains of an individual, radiographs of such dried bone may reveal the timing of injuries that took place shortly before death and elucidate more information on the trauma that occurred. The importance of such fracture healing rates with pediatric radiographs lies with many child abuse cases. Child abuse has become a relatively recent research topic, with focus growing on it within the later half of the twentieth century (Brogdon 1998; Kerley 1978). Trauma in pediatric cases remains an imperative topic, as within the United States alone, there are approximately 2,000 children dying per year due to child abuse; furthermore, many of these children are under the age of 4 (Brogdon 1998). Additionally, fractures that occur in children under age three are more likely to be associated with child abuse than the skeletal injuries of older children (Kleinman 1987). While not all child abuse can be documented skeletally, there are skeletal injuries that may indicate its occurrence, such as appendicular trauma, rib fractures, and injuries to the shoulder girdle region (Brogdon 1998). Additionally, multiple fiactures at different stages of healing are often considered indicative of child abuse (Walker et a1. 1997; Kerley 1976; Gwinn et a1. 1961). When such skeletal trauma occurs, radiographs are the typical method employed for examining the injury of the child, with CT or MRI added for head injuries. While typically forensic anthropology cases are often limited to skeletal remains, there is also the possibility of examining radiographs that indicate the patterns of trauma to the bone in a living subject or in skeletonized remains. The aims of the present study are to extrapolate data on fracture healing from radiographs, evaluate rates of fracture repair in young children, and compare how these rates vary with the age of the individual and the skeletal element involved. Very few radiographic studies have focused on pediatric fractures; thus, through the present research, an outline for what can be expected in the fracture healing process based on pediatric radiographs has been developed. The goal of this project is to construct and describe stages, based on radiographs, that indicate the amount of healing that is expected by a certain time and to demonstrate how soon there may be radiographic evidence for fracture healing in pediatric cases. The importance of the suggested study lies with the forensic anthropological analysis of pediatric skeletal cases. In such an instance, a forensic anthropologist must “note carefirlly the stages of healing of different fractures in remains of children who have multiple fiactures that occurred prior to time of death as well as any fractures that are unhealed and may have occurred at the time of dea ” (Kerley 1976: 337-338). Additionally, when assessing such skeletal remains, radiographic examination can aid in the confirmation of antemortem versus perimortem injuries, as the antemortem injuries will display a radiopacity associated with healing bone (Kerley 1978). Thus, through radiological data on the healing rate of pediatric fractures, the forensic anthropologist will be given another tool to assess the timing of traumatic injuries in the assessment of skeletal fractures. Additionally, within child abuse cases, the estimation of the timing of injuries is often complicated by the abuser’s delay in seeking medical care (Walker et a1. 1997; Brown 1976). The present study will be an attempt to assist in confirming or refuting the proposed timing of injuries. CHAPTER 2: BACKGROUND — FRACTURE HEALING Fracture healing is a unique process, and while the rate healing occurs may vary, it is important to understand the physiological reaction of the bone after fracture occurrence. Fracture healing is normally broadly grouped into three stages: inflammatory, reparative, and remodeling (Jones 2003). At the time of trauma, the fracture event causes blood vessels to rupture and a hematoma to form, indicating the inflammatory stage. Afier the initial trauma, bone reacts by osteoprogenitor cells differentiating to form fibroblasts and other cells. These cells will then form a soft, fibrous, granular tissue at either end of the fractured bone and extend in to and replace the forming hematoma, thus signaling the beginning of the reparative stage. While no new bone is actually formed at this point, it represents the first structuralizing that occurs at the fracture site. Next, a primary woven bone callus forms. increasing the stability of the weakened fracture site. Within this primary callus there are three different types of calluses connecting the bone: a sealing callus (joining the broken ends), an endosteal callus (joining the opened marrow cavity), and a periosteal callus (bridging over the entire site). A bulging shape is typical of the periosteal callus. A third step in this process is the primary woven bone callus being replaced by a secondary lamellar bone callus. The woven bone, and eventually any excess callus, will be resorbed (Ortner 2003; Hendrix 2002; Frost 1989). Finally, during the remodeling stage, the bone is recontoured and restructured internally, a process which can take place concurrently with lamellar bone remodeling (Frost 1989). During life, the osteogenic properties of bone allow healing to transpire. While the healing of bone is normal, the rate at which this process occurs can vary among individuals and among different bones and locations within the body (Ortner 2003). The medical literature addresses the stages of bone healing and the remodeling rates, yet often these articles suggest subtle differences, making an exact timescale a complicated task (Hufnagl 2005).While these stages may be considered an arbitrary assignment, such a categorization may be useful when studying the expectations of fracture repair (Hendrix 2002). The process of healing can be understood at a number of different levels: clinical radiographic, biochemical, or histological (Hendrix 2002). The radiographic assessment of fracture healing, while relatively absent in the forensic anthropology literature, has its foundation in the medical realm. Both Toal and Mitchell (2002) and Hendrix (2002) have examined radiographic characteristics of fracture healing. Immediately following fracture, bone edges will appear clearly outlined, with a blurring of this line within five to fourteen days. Following this, a “fluffy” callus appears and becomes radiopaque. An initial bridging of the callus may be present around the one month mark. Several months after the initial fracture, the fracture line may become obliterated, after which remodeling takes place (Hendrix 2002; Toal and Mitchell 2002). The use of radiographs to evaluate the stage of fracture healing is somewhat controversial and the research has been limited by small samples of human subjects or animal studies. In 1991, De Palma and colleagues carried out a study of radiographic images, examining adult femoral fractures in Italy. The authors examined 15 radiographs of femoral fractures before and at one, two, four, and six months after surgery. From such research, the authors concluded that radiographs can be used to assess the stage of remodeling in fracture repair (De Palma et al. 1991). While this study indicates the promise of radiographic assessment of fracture healing. there are also studies indicating its weaknesses. In 2001, Blokhais and colleagues (2001) carried out a study using radiographs to assess the healing process in mid-shaft tibial fractures of goats. In this instance, the authors felt that radiography was a poor indicator of the healing process (Blokhais 2001). While there are investigations indicating conflicting results when using radiographs to assess fracture healing, there are also analyses that have used radiographic assessment of fracture healing to determine the effect of various factors on the healing process. For instance, Kline and colleagues (2005) used radiographic assessment to determine the impact of BMP-14 deficiency in mid-shalt femoral fractures of mice. In this study, the authors stated that such radiographic grading was able to indicate fracture healing within a range of one to four days (Kline et al. 2005). Other studies have also employed radiographic stages of fracture healing, specifically in non-human samples (Risselada et al. 2005, Heybeli et al. 2002). Researchers have also developed methodology for the actual assessment of fracture repair from radiographs. Tiedeman and colleagues (1990) devised a scoring system for assessing fracture healing in adult dogs, based on several features: the amount of bone formation, the amount of the fracture line present, and evidence of remodeling on the intramedullary canal and cortex (Tiedeman et al. 1990). Also, in 2003, Grigoryan and colleagues examined radiographs and CTs of 39 adult men and women with radial or tibial fractures at one, two, four, eight, twelve, and sixteen weeks post-fracture. In this analysis, the authors were able to determine a time frame of eight weeks for radiological union of the fracture. based on the presence of radiographic features, such as lines. fracture gaps, callus appearance. callus-to-cortex ratio, and radiological union (Grigoryan et al 2003). Additionally, Langley-Hobbs examined the fracture healing process in small animals. She identified two types of healing that may occur: primary/direct and secondary/spontaneous. In the former case, clinical union may be present prior to radiographic union, whereas in secondary healing, clinical union may not be achieved until weeks after radiographic union (Langley-Hobbs 2003). Clinical union commonly refers to the point in the healing process at which fixation devices may be removed, radiographic union, on the other hand, refers to the point in the healing process where bridging is present over the fracture gap (Langley-Hobbs 2003). Secondary healing. occurring afier external stabilization of the region, is indicated radiographically by resorbtion (indicated by the loss of sharp edges), callus formation (indicated by callus visibility), healing (indicated by fracture lines and the callus increasing in opacity), and remodeling (indicated by the cortical shadow becoming visible). Primary healing, associated with internal stabilization of the fracture and a very minimal gap at the fracture site, may be indicated by reduced density at the fracture site, seen as a “smudging” at the interface (Langely-Hobbs 2003: 32). Thus, each stage of fracture healing has certain characteristics associated with it. In 2005, Hufnagl conducted a study to devise a method of determining age-since- trauma based on radiographic images. He examined 62 sets of radiographs (each set being comprised of a minimum of four radiographs), coming from individuals aged two to 93. Information was included on the sex of the individual, the ancestry of the individual, the type of fracture, and the date of the fracture. Additionally. fractures were examined from radius, tibia, and femur. From this sample, Hufnagl presented six stages of fracture healing that are demonstrated radiographically: fracture, granulation, mature callus, partial bridging, almost complete bridging, and complete bridging. The time of healing was also determined for each of the sets of radiographs. This data allowed Hufnagl to examine the role of age, sex, ancestry, and weight placed on the bone in the healing rates. Of these factors, it was found that only age was significantly correlated with the stages of fracture repair (Hufnagl 2005). The phases of radiographic healing used by Hufnagl are of particular importance to the present study and will be described further here: 1: Fracture Event — absence of observable bone healing Figure 1: Fracture Event. Reproduced from Hufnagl (2005). 10 2: Granulation — beginning of resorption along the fracture fragments and the initial indicators of callus formation; widening of the fracture gap due to resorption, blurring of the fragment edges, and appearance of faintly mineralized buds of callus (fluffy callus). Figure 2: Granulation. Reproduced from Hufnagl (2005). 3: Mature Callus - radiopaque and appears as dense as regular bone with the exception of its bulging out and over the fracture gap; fracture line still clearly defined. Figure 3: Mature Callus. Reproduced from Hufnagl (2005). 11 4: Partial Bridging — refers to point in time when the callus is connected across the fracture gap in some areas; fracture line is beginning to blur and is not clearly evident along some portions of the fragments. Figure 4: Partial Bridging. Reproduced from Hufiragl (2005). 12 5: Almost Complete Bridging — points in fracture healing when fractures are classified as clinical union; fiacture line is almost completely blurred 6: Complete Bridging — fracture line is completely eradicated in the x-rays and evidence of the line is not longer observable (Hufnagl 2005). Figure 5: Almost Complete Bridging (tibia) and Complete Bridging (fibula). Reproduced from Hufnagl (2005). 13 CHAPTER 3: BACKGROUND — INFLUENCE OF AGE While similarities abound in the healing process between children and adults, it is important to realize children are not merely miniature adults; children have their own unique skeletal and physiological characteristics. Sub-adult bone is undergoing growth, and as such, may heal at a faster rate (Hobbs 1989; Kempe et al. 1962). Studies have indicated that in children it is possible for ossification or even for full strength to be regained after 10 days (Lewis 2007; Ogden 2000). In an examination of 275 femoral fractures in 265 children under the age of 18, Skak and Jensen found that the time for fracture union varied between three weeks and two years (1988). The researchers discovered that side, sex, type of trauma, or type of fracture did not affect the amount of time required for union, but age was demonstrated to influence healing time based on a log-normal distribution with an increment in mean time to union of 0.7 weeks per year (Skak and J enson 1988). This study and others demonstrate that the rate of healing has been directly related to age — the younger the individual, the faster the healing (Glencross and Stuart-Macadam 2000; Jones 2003). For instance, a femoral fracture in an infant may heal in 3 to 4 weeks, whereas a similar fracture in an adolescent may take 12 to 16 weeks to heal (Jones 2003). The variations in healing time between children and adults necessitate further examination of pediatric fracture healing. The rapid healing in children can contribute to a loss of any deformity that could have resulted from trauma, masking injuries that would have been more dramatic in their adult counterparts (Lewis 2007). While faster healing is acknowledged in pediatric fractures, there is no radiologic evidence that has been shown to substantiate this tenet (Prosser et al 2005). Due to variations in bone trauma and healing that are associated with 14 age, anyone who is assessing pediatric fractures should be aware of the mechanisms of injury, the causes, the acute responses, the treatments, and the long-term effects of fractures in children (Ogden 2000). Particularly, the differences between adult and pediatric skeletal injury should be described based on variations in anatomy, physiology, and biomechanics (Ogden 2000). The anatomy of pediatric bone differs from the mature bone of adults. The ossification and union patterns of the sub-adult skeleton create differences in the likelihood of fracture and in the healing time of certain regions of bone. For instance, consider the dense bone of a diaphysis compared to the spongy bone of the metaphysis and epiphysis (Ogden 2000). Young children, and more specifically infants, are afforded increased defense against skeletal injury through their unmineralized bone. As ossification occurs, the thinning areas of the physes become increasingly prone to injury (Glencross and Stuart-Macadam 2000). In addition to the ossification and union patterns of the sub-adult skeletal, the increased vascularity and periosteal characteristics will cause bone to heal at a faster rate. Ogden (2000) gives an eloquent review of the impact of such features on the fracture healing process. Ogden notes that at birth fracture healing is “remarkably rapid,” but immediately the repair process begins to decrease through childhood and adolescence (2000:42). The thicker, stronger periosteum of pediatric bone tends to resist displacement and is more biologically active, decreasing the healing time. Pediatric periosteum, while thicker, is more likely to separate from the bone. Ogden (2000) states that this characteristic aids in preventing complete rupture of the periosteum generating an “intrinsic stability” due to less displacement of fracture fragments. As an individual ages, 15 the periosteum thins, decreasing in osteogenic activity and lengthening the healing time required for skeletal injury (Jones 2003). Pediatric physiology implies that a child will respond differently to the metabolic and physiological stresses of skeletal trauma than an adult. Adults will have an increased metabolic demand after trauma, whereas in children there is little or no difference detected (Ogden 2000). Children tend to have an already high metabolic rate so less of a change is necessary when trauma occurs, perhaps accounting for the increased survival rate after severe trauma when compared to adults. While afforded some physiological protection after a traumatic occurrence, children may be at a higher risk for hypovolemic shock or hypothermia due to blood volume and surface area ratios (Ogden 2000). Such physiological reactions may influence the repair process and rate of healing of the traumatized bone. Due to the differences in bone structure and bone composition, the skeleton of a child has unique biomechanical properties. Sub-adult bone is less brittle, more porous, contains larger haversian canals, contains more water, and has a lower mineral content (Auringer 2002). These characteristics lend to an increased elasticity and plasticity in children’s bone (Auringer 2002). Generally, adult bone has ceased apposition and is only responding to the stresses placed on specific skeletal elements (Ogden 2000). Additionally, adult bone tends to fail in tension, whereas pediatric bone may fail in tension, compression, or both (Ogden 2000). The biomechanical properties of pediatric bone, creating an increased capacity for plastic and elastic deformation, give rise to an increased tendency for tensile failure to be deficient, leading to incomplete fractures. such as plastic deformation and greenstick fractures (Ogden 2000; Auringer 2002). The 16 porosity of bone and rough surface that results from pediatric bone structure contribute to the need for increased energy and time before bone will fail, aiding in the prevention of complete fracture (Jones 1994). As an individual ages, the plastic phase of bone deformation is shortened, increasing the vulnerability for complete fracture. When skeletal trauma does occur in children it tends to present as physeal fractures, torus fractures, greenstick fractures or even as plastic deformation without fracture (Lewis 2007). Physeal fractures, the only complete fracture mentioned, involve the growth plate of the bone. Such injury may lead to angular deformity, irregular shortening, or joint incongruity. Torus fractures occur when there is a failure of cortical diaphyseal bone causing the membranous metaphyseal bone to be affected resulting in a slight bulging at the diaphyseal/metaphyseal junction. Greenstick fractures occur when bending on the compression side allows the cortex and periosteum to remain intact, while the force causes fracture on the tensile side. Plastic deformation, which may occur in a fall where the hands are outstretched. results in a broad curvature over the length of the bone (Glencross and Stuart—Macadam 2000). As evident from the types and frequencies of injuries, youth contributes to some intrinsic protection from harm. The types of fracture and injuries also differ between children and adults. Due to their small size, children may be more susceptible to fatal soft tissue injuries. Altemately, the forces of falls are not as great due to the small size of children, preventing more serious injuries from occurring. Essentially, most childhood injuries tend to be low- impact “trip, stumble and fall” occurrences (Auringer 2002). The risks and typical mechanisms of injury also vary with age. According to modern clinical data, each age group will have 3 characterized pattern of fracture varying in location and nature. Each 17 age may even have a “typical injury” (Jones 1994). For instance, today, children under the age of one are most susceptible to physical abuse, children ages five to 10 are vulnerable to falls and traffic-related injuries, and older children are more likely to incur sports-related injuries (Glencross and Stuart-Macadam 2000). Due to non-mobility, children under the age of two are likely to have sustained injuries by having someone else injure them (Jones 2003). While the hazards children encounter have undoubtedly changed over the years, it is likely there are similarities in fiacture causation. To illustrate, consider the increase in activity of children over their lifetime. All children will encounter falls, but infants are unable to protect the more vital areas of their bodies. In non-ambulatory children, falls are a common traumatic event that may result in fractures to the clavicle or skull. Ambulatory children will be more likely to suffer fracture to the limbs due to attempts to break their falls (Glencross and Stuart-Macadam 2000). The characteristics of sub-adult bone continue to influence the traumatized region after a fracture has occurred. Due to the increased vascularity of pediatric bone, the inflammatory process occurs at a faster rate and plays a greater role in the healing process. This increased response time shortens the early stages of fracture healing in children, when compared with adults (Jones 2003; Ogden 1982; Ogden 1963; Rang 1983). Furthermore, the subperiosteal callus that forms during pediatric fracture healing contributes an increased stability to the fracture site, which may allow the fracture to be considered healed by the end of the reparative stage (Jones 2003). While pediatric fractures may heal at a faster rate, they may not always remodel. Remodeling capacity in children is based on the age of the child, the distance of the fracture from the end of the bone, and the amount of angulation (Ogden 2000; Jones 2003). Satisfactory remodeling 18 tends to occur in children with two years of growth ahead, fractures near the ends of the bone, and injuries not associated with the movement of a joint (Ogden 2000). On the other hand, delayed union or non-union are uncommon in children due to the increased healing capacity of pediatric bone (Ogden 2000). In addition to the biomechanical properties of bone itself, the child, as a patient, differs significantly from his or her adult counterpart. Of concern for pediatric patients is the potential for lack of patient history or erroneous data, especially problematic in abused children. A child’s account of the traumatic incident tends to be inaccurate or incomplete, whereas the parent or guardian may not have witnessed the occurrence (Ogden 2000). Follow-up care may also be problematic. While often recommended to continue follow-up until six months to a year after injury, most parents or guardians will discontinue medical assessment when their child appears to be better (Ogden 2000). Child Abuse Child abuse, often considered a modern clinical phenomenon, should be considered in all pediatric skeletal trauma cases (Jones 2003). Furthermore, any profession dealing with sub-adult skeletal injuries should be familiar with the indications and trauma associated with child abuse (Kleinman 1987b). Skeletal trauma, while not often life-threatening in child abuse cases, can leave evidence of recent trauma as well as well-healed injuries. Additionally, the high frequency of skeletal trauma in child abuse cases suggests that further examination is necessary in pediatric fracture cases (Kleinman 1987b). l9 The documentation of child abuse, while having a significant history, has only been identified within the past century. In 1946, Caffey examined long bone injuries in six infants with subdural hematomas. Through the correlation of these injuries, he recognized the reality of child abuse and brought it to the attention of others in the medical field. Caffey’s catalyst prompted other medical professionals to examine children for abuse through clinical and radiographic evidence (Kleinman 1987b). In 1962, “Battered Child Syndrome” (BCS), coined by Kempe and colleagues, indicated that certain skeletal injuries including appendicular trauma, rib fractures, and injuries to the shoulder girdle region may be suggestive of child abuse (Brogden 1998). Battered Child Syndrome identified such fundamental injuries as a clinical condition in which serious physical abuse is directed at children. The key to identifying Battered Child Syndrome is multiple fractures in various stages of healing (Walker et al. 1997; Kerley 1976; Kempe et al 1962; Gwinn et al. 1961). The skeletal surveys, including radiographs, of abused children may demonstrate multiple injuries in various stages of healing, findings inconsistent with the history provided by a parent or guardian, metaphyseal lesions, and fractures of ribs, sterna, vertebrae, and scapulae (Auringer 2002). The most common injuries in abused children tend to occur on long bone diaphyses, except in infancy, when skull, metaphyseal, and rib fractures are more common (Auringer 2002). Eighty percent of the fractures in abused children occur when the child is under the age of 18 months; in nonabused children 85% of fractures occur after the age of 5 years. In children under one year of age, fractures are relatively uncommon, yet multiple severe fractures during the first postnatal year may indicate a problem (Auringer 2002). Evidence for abuse may seem unquestionable, yet such a conclusion is still problematic. While the identification of such features may quickly prompt action from a medical practitioner, before child abuse may be addressed “metabolic disorders or skeletal displasias must be considered.” (Ogden 43:2000). After the elimination of such conditions, the “diagnosis” of child abuse requires either indisputable radiological evidence of fractures or fractures that were not consistent with the given history (O’Connor and Cohen 1987). While the mechanism of injury would obviously be one manner in which to dispute the history of injury, the ability to date fractures would further enable a radiologist or anthropologist to confirm or refute the stated occurrence. For instance, consider a child brought to the hospital. The parents have stated that the child fell off a bicycle landing onto an outstretched hand earlier that morning. When the child is examined there is indeed a fracture to the forearm, but instead of the fresh injury that would be expected, the fi'acture seems to have been healing for several days. In this case, the story given by the parents may have been erroneous. While the mechanism of injury was consistent with the fracture, the timeframe given was not. This inconsistency may indicate that the parents where unwilling to give a complete and true account of what occurred. While child abuse has only recently been identified clinically, it does merit a historical and anthropological examination. Beating children in the past has been socially sanctioned in some groups of people and is presented in historical documents (Walker 2001a; 2001b). For instance, consider this Old Norse rhyme dating from the 17th century: The child will not be quiet, the child will not be quiet, Take it by the leg and hit it against the wall, The child will not be quiet. Cited in Lewis (2007:175) 21 Child abuse is also mentioned in literature from physicians, dating to medieval times and earlier (Lewis 2007). The historical view on child abuse has suggested that children were traumatized in a variety of manners, including freezing, burning, drowning, shaking, mutilation, and throwing (De Mause 1974). Ironically, child abuse, a cause of more than 2,000 deaths in the United States today, is absent in the archaeological record (Lewis 2007; Brogden 1998). In an examination of more than 5,000 skeletal remains of prehistoric children, Walker and colleagues (1997) found no examples that were comparable to present day instances of child abuse. In addition to multiple fractures in different stages of healing, subperiosteal lesions were examined in modern cases of chronic abuse. These lesions appear localized, asymmetrically located, and in various stages of healing (Walker et al 1997). While subperiosteal lesions are undetectable by radiography, an experienced physical anthropologist should be able to readily identify any healed lesions present (Walker et a1 1997). Such subperiosteal lesions are absent in the archaeological record, indicating that this pattern of physical abuse did not occur until modern times (Walker et a1 1997). With the fragmented and sometimes poorly preserved sub-adult remains, it may be difficult to properly identify and examine the lesions. For instance, if an isolated long bone fragment were found, the distribution of other lesions on the individual could not be identified. Additionally, preservation issues may affect the quality of bone available, especially compared to modern forensic examples. Finally, such a lesion could be mistaken for bone inflammation or periostitis due to some underlying disease process (Ortner 2003). Other postulations as to the reasons for the lack of skeletal evidence of physical child abuse have also been made. Walker suggests that the abuse of children may have been 22 impossible in past societies, as kin-based groups would have led to an intervention (Walker 2001a). The small sample sizes of bioarchaeology have been criticized for hiding the evidence of child abuse. Even considering today’s rates of child abuse, one would need to examine approximately 2,000 infant remains to find just one instance of child abuse in the skeletal record (Waldron 2000). At the same time, while Battered Child Syndrome would be expected to be uncommon, there are even more rare pathologies and disorders that have been found in the archaeological record, indicating that if child abuse was present, researchers would have inevitably seen at least several instances in the extensive bioarchaeological examinations that have taken place (Walker 2001b). It is the inexplicable lack of skeletal evidence for child abuse that has led numerous researchers to conclude that it did not exist in the past. With various historical documents referring to the beating of children and to some extent its acceptance, there seems to be a contradiction between what has been described and what is actually observed on skeletal remains. Walker (2001b) suggests that this contradiction may be partially due to the differences in the patterns of child abuse. For instance, historical records often refer to older children, while the modern definition of battered child syndrome is typically seen in children under the age of three (Walker 2001b; Kempe et a1 1962). Additionally, if past child abuse was less fatal, children would survive into adulthood with very little evidence of trauma ever occurring. Walker (2001b) also postulates, that if Battered Child Syndrome is a recent occurrence, social conditions, control and support may have degraded and contributed to the increased violence seen toward children today. 23 The past of child abuse remains questionable, yet the current presence of these traumatic occurrences emphasizes the importance of examination of pediatric injuries. With the broad definition of child abuse, including physical harm, sexual assault, neglect, and physiological abuse, not all abused children will demonstrate skeletal injury indicating physical abuse (Kleinman 1987a). Furthermore, not all pediatric skeletal injuries can be indicative of child abuse. Instead, it is essential to consider the reality of abuse when clinically examining children or when anthropologically examining sub-adult remains. Radiography of Pediatric Fractures With child abuse cases, a complete skeletal survey is performed to assess the current injuries and possibility of past trauma. Radiographs are considered imperative in the skeletal survey of all infants demonstrating physical abuse (Merten et al 1983). A skeletal survey of potentially abused children will typically consist of an anterior view of the appendicular skeleton and both anterior and lateral views of the axial skeleton (Kleinman et a1 2004). In the past, a “babygram,” a single image of an infant exposed on one or two radiographic films, has been considered sufficient documentation, yet more thorough radiography of the trunk, spine, and skull are necessary when examining potential abuse victims (Kleinman et a1 1989). Postmortem radiographs are also of use when examining the extent and sequence of pediatric fractures in unexpected deaths (McGraw et a1 2001). Radiographs obtained contribute to valuable evidence that may be used in prosecution of abusers. 24 Radiography has also played a part in distinguishing child abuse from accidental trauma encountered in infants and young children. In one such study, Cumming analyzed a sample of 23 infants who suffered fracture from delivery attempting to distinguish birth trauma from child abuse (1979). The sites of skeletal trauma resulting from delivery included fiactures to the clavicle, humerus and femur. Additionally, Cumming states that calcification on radiographs of fiactures at the time of birth would be present between seven and eleven days after birth, thus enabling an examiner to distinguish between postnatal accidents from perinatal trauma (1979). The accessibility of pediatric radiographs and the possibility of extracting evidence from the images, generate a need to establish more precise radiographic healing stages. Few studies have addressed the radiographic assessment of fracture healing in children. The studies that do attempt to correlate specified radiographic signs with a certain amount of healing. Yeo and Reed (1994) examined one aspect of radiographic fracture healing, the callus, in a preliminary study of 25 children fi'om birth to age 14 to determine the influence of sex and age on healing time. Serial radiographs of the femur were examined and categorized into three stages of callus formation. Stage 1 was indicated by the first radiographically visible sign of callus. Stage 2 was demonstrated when complete bridging of the callus was present. Stage 3 was defined by a smooth, homogeneous density callus with a fracture line still visible. Results indicated no difference in healing times based on sex and no statistically significant results for age. The researchers did state that a trend toward increased healing time with patient age was present at Stage 3 only; with an increased sample size more dramatic results may be 25 expected (Yeo and Reed 1994). Yeo and Reed concluded that further studies and a more accurate method of assessing fracture healing are needed (1994). Following Yen and Reed, Islam and colleagues (2000), examined a collection of radiographic features in a sample of 707 radiographs from 141 children, ages one tol7. Two hundred five fractures to the radius or ulna were present in the sample, with between two and eight radiographs per fracture. The researchers examined the effect of sex. age, displacement, and location on the radiographic signs (sharp/blunt fracture margins, fracture gap, periosteal reaction, callus density, bridging, and remodeling). Blunting of fracture margins was noted at one week, though the presence of casts limited this finding. Periosteal reactions, fracture gap widening, increased bone density, and callus calcification were seen by two weeks. Partial bridging at the fracture site was seen as early as three weeks and remodeling was seen as early as four weeks. No radiographic signs of healing were present prior to five to seven days after the traumatic event. In the analysis of the radiographic characteristics, the researchers found no statistically significant difference associated with sex, age, displacement or fracture site (Islam et al 2000). The study, while demonstrating the importance of assessing more than one radiographic feature was limited in the number of individuals under the age of four. The small amount of individuals in an age group particularly vulnerable to abuse, demonstrates the need for larger studies to assess fracture healing in infants and young children (Prosser et al 2005). Whether abuse is suspected or not, pediatric bone may be difficult to assess radiologically. While increasing fracture healing rates, the anatomy and biomechanical properties of sub-adult bone makes radiographic examination slightly problematic. 26 Children are undergoing endochondral ossification, thus the unfused epiphyses of children may be variably radiolucent (Ogden 2000). Generally, bones should be radiographed in two different planes: anterior-posterior and lateral. While one View will usually depict the fracture, not all fractures are seen on both views (Ogden 2000). Furthermore, the tendency for pediatric fractures to be incomplete or minimally displaced increases the difficulty of clinically or radiographically identifying the trauma (Dunbar et al 1964). Understanding the ossification and fracture patterns of pediatric bone is essential when radiographically examining skeletal injury. 27 CHAPTER 4: BACKGROUND - INFLUENCE OF FRACTURE LOCATION Forearm Fractures of the forearm represent a common injury in both children and adults, yet the age group most likely to suffer such an injury is individuals between the ages of five and 14 years (Chung and Spilson 2001). Additionally, forearm fractures are the most common location of skeletal trauma in childhood, accounting for approximately 25-40% of all fractures. and 62% of upper limb fractures (Auringer 2002; Jones 2003; Armstrong et al. 2003; Waters and Mih 2006). Of forearm fractures, the distal aspect of the forearm is the most likely site of fracture, but the shaft of the forearm is the most likely reason for orthopedic involvement (Waters and Mih 2006, Mehlman and Wall 2006). The high frequency of skeletal trauma to the forearm and the extent of orthopedic participation in these injuries, especially in childhood, make the forearm an ideal location to examine in the present study. Fractures to the shaft of the forearm tend to occur when an individual falls onto an outstretched hand. In children, this ofien results in a torus or buckle fracture; with greater force, a greenstick or complete fracture may occur (Keogh et al. 2002) Often increased force results in fracture to both the radius and ulna, though in such circumstances the fracture to the radius may be more severe (Keogh et al. 2002, Cox and Sonin 2002). Forearm fractures are often group grouped generally into “both-bone fractures” and “greenstick fractures” (Mehlman and Wall 2006). When complete both-bone forearm fractures occur, the injury may be adequately manipulated in a closed reduction. Greenstick fractures may require complete breakage before the fracture can be properly reduced (Cox and Sonin 2002). Both-bone fractures. which may demonstrate fracture at different levels for the radius and ulna, occur when a child falls (Mehlman and Wall 2006). Isolated fractures, on the other hand, tend to occur from direct blows or associated dislocations (Cox and Sonin 2002: Mehlman and Wall 2006). Forearm fractures may be diagnosed and monitored radiographically and clinically. To radiographically examine forearm fractures, an anterior-posterior view and lateral view are required to confirm the diagnosis (Cox and Sonin 2002). While precise healing times vary, the radiological union of fracture fragments in the forearms of adults may be indicated around 8 weeks, whereas in children, forearm fractures heal at a more rapid rate (Hertel and Rothenfluh 2006: Baitner et al. 2007). Leg Nonphyseal fractures of the leg are among the most common in the lower extremities of children, and are the third most common pediatric long bone injury (Jones 2003; Heinrich and Mooney III). A majority, 70%, of tibial fractures is an isolated occurrence; the remaining 30% involve the fibula as well (Heinrich and Mooney III). When more force is involved, both bones are more likely to fracture, whereas. when an isolated tibial shafi fracture occurs it commonly presents as a spiral fracture. Spiral fractures in particular have often been cited as evidence of child abuse (Mellick et al 1988). The tibia is one of the most commonly fractured bone in abused children, and often, unlike what is expected with Battered Child Syndrome, a single fracture may be all that is present (Loder and Bookout 1991; King et al 1988). Due to the prevalence of tibial fractures in childhood and their potential association with child abuse, the tibia was selected as another location to examine in the present study. Often the indirect forces associated with falls generate a spiral or oblique fracture in the tibia with no associated fracture of the fibula; high impact, direct injuries are more likely to involve both bones (Helms and Major 2002). Specifically in children under the age of four, tibial fractures tend to be the former, often located in the distal and the middle one third of the bone (Heinrich and Mooney III 2006). Spiral fractures of the tibia may require open reduction and internal fixation due to the high frequency of delayed union and re-fracture occurrence (Helms and Major 2002). Toddler’s fractures, a specific type of lower limb fracture, are an undisplaced spiral fracture of the distal tibia that occurs in children around the age of two (Dunbar et al 1964). Such injuries are commonly sustained as a result of one of a child’s numerous falls. After the fall, the child refuses to bear weight on the leg, with radiography revealing the spiral fracture (Helms and Major 2006) Fractures of the shaft of the tibia and/or fibula require the entire length of the bone or bones to be radiographed; this radiography is needed to ensure rotation is evaluated and to determine if fractures are present on the other bone at a site distant from the fracture of the first bone (Helms and Major 2002). Often spiral fractures may be seen in either an anterior-posterior radiograph or a lateral radiograph, but not visualized well in the other; therefore, two views are required to confirm the fracture (Helms and Major 2002). Tibial fractures are notorious for their long healing times. In adults, tibial shaft fractures heal in approximately 16 weeks in adults, but in children the healing occurs at a faster rate (Helms and Major 2002). The exact healing time of tibial shaft fractures depends on the severity of the injury, including the displacement of fracture fragments, 30 the degree of comminution, whether the injury is open or closed, and whether other complications, such as infection. are present (Helms and Major 2002). While typically fractures will be healed after several months, the fracture may be defined as a delayed union if the site remains open beyond 20 to 24 weeks. Nonunion is indicated by the fracture line remaining open without formation of a periosteal callus for 6 months to a year after the fracture occurrence (Helms and Major 2002). In addition to the decreased healing time, the distal tibia is known for an increased frequency of nonunions and delayed unions when compared with other elements throughout the skeletal system (Helms and Major 2002). 31 CHAPTER 5: QUESTIONS AND HYPOTHESES The aims of the present study are to determine the applicability of radiographic assessment to pediatric cases, produce stages of radiographic healing and descriptions, and provide a timeline for the stages of healing in infants and young children. There has been little research done on this topic in the past, as most investigations have centered on known adult radiographs or traumatized non-human long bone specimens. While these past studies have had a different focus from the present study, the radiographic characteristics and features of fractures described in the past may be modified and used when describing the radiographs and developing the stages of fracture healing to be analyzed in this study. Specific Aims The specific aims of this study are as follows: 1. To collect and digitize a set of radiographs from a sample of infants and young children that represent different stages in the healing process of tibial and radial fractures for each subject. 2. To develop a series of stages (from the literature) to describe and measure the typical bone fracture repair process. 3. To evaluate, for each radiograph, the stage of fracture repair. 4. To segment the sample by age group (0-1 years, 2-3 years, 4-5 years) and evaluate the variation in fracture repair rates. An average number of days of healing for each stage will be calculated for each group and an analysis of 32 variance (ANOVA) will be used to determine the significance of calculated means. 5. To evaluate the variation in fi‘acture healing rates among different skeletal elements (tibia and radius). An average number of days of healing for each stage will be calculated for each skeletal element and a t-test will be used to calculate the significance of the calculated means. 6. To summarize the data and present mean healing times for each of the stages of fracture repair for the three age groups and for each skeletal element examined. Hypotheses Hypotheses were generated to allow for the statistical analysis in Specific Aims 3, 4 and 5. Hypotheses of this study are as follows: 1. Null hypothesis 1: No differences in mean healing time will be seen among Stages 1-6. 2. Null hypothesis 2: No difference in mean healing time will be seen among group A (0-1 years), group B (2-3 years), and group C (4-5 years). a. Null hypothesis 2a: No difference in mean healing time in Stage 1 will be seen among group A (0-1 years), group B (2-3 years), and group C (4-5 years). b. Null hypothesis 2b: No difference in mean healing time in Stage 2 will be seen among group A (0-1 years), group B (2-3 years), and group C (4-5 years). 33 Null hypothesis 20: No difference in mean healing time in Stage 3 will be seen among group A (0-1 years), group B (2-3 years) and group C (4-5 years). Null hypothesis 2d: No difference in mean healing time in Stage 4 will be seen among group A (0-1 years), group B (2-3 years) and group C (4-5 years). Null hypothesis 2e: No difference in mean healing time in Stage 5 will be seen among group A (0-1 years), group B (2-3 years) and group C (4-5 years). Null hypothesis 2f: No difference in mean healing time in Stage 6 will be seen among group A (0-1 years), group B (2—3 years) and group C (4-5 years). 3. Null hypothesis 3: No difference will be seen in mean healing time between the tibial shaft and the distal radius. a. b. C. d. Null hypothesis 3a: No difference will be seen in mean healing time in Stage 1 between the tibial shaft and the distal radius. Null hypothesis 3b: No difference will be seen in mean healing time in Stage 2 between the tibial shaft and the distal radius. Null hypothesis 3c: No difference will be seen in mean healing time in Stage 3 between the tibial shaft and the distal radius. Null hypothesis 3d: No difference will be seen in mean healing time in Stage 4 between the tibial shaft and the distal radius. 34 e. Null hypothesis 3e: No difference will be seen in mean healing time in Stage 5 between the tibial shaft and the distal radius. f. Null hypothesis 3f: No difference will be seen in mean healing time in Stage 6 between the tibial shaft and the distal radius. Expected Results Through the radiographic analysis of stages of healing and the background research, the following results are anticipated: 1. The younger the individual, the faster the healing will occur. 2. Forearm fractures will heal faster than lower limb fractures. 3. These differences will be most evident in the beginning of the fracture healing process. 35 CHAPTER 6: METHODS AND MATERIALS Materials For this project, a collection of radiographs obtained from Dr. Edward Sladek (an orthopedic specialist in Lansing, MI) was used. Radiographs of fractured bones (radius and tibia) from infants and young children of ages 0-1, 2-3, and 4-5 were included, with ages taken from the time of initial injury. The individuals in the sample represented male and female children of known age and time of injury from a mid-Michigan population. The radiographs examined consisted of sets of images from each individual. If only one radiograph was available, the individual was not excluded, as there may have been healing evident with an associated time frame. The number of serial radiographs ranged from one to 11, with an average of three radiographs per patient. Any individuals demonstrating co-morbidity or any systemic disorder, such as diabetes or osteogenesis imperfecta, which may affect the bone healing rate was excluded from the study. The total sample that was examined consisted of 107 individuals and 294 radiographs. Table 1 summarizes the categorization of the sample. Table 1 — Summary of Sample Age 0-1 Age 2-3 Age 4-5 TOTAL Forearm 15 15 30 60 Leg 16 16 15 47 TOTAL 31 31 45 107 36 Methods The radiographs were digitized. Digitization was performed by photographing the radiographic images on a light board. A tripod was set-up and a Canon Rebel X digital SLR camera with a 50mm macro lens was directed perpendicular to the radiographs. Images were saved on an external hard drive and were labeled according to individual and radiograph date. Multiple radiographs taken on the same date of the same individual were labeled alphabetically. For instance, the first radiograph taken on July 15, 1996 of individual 1, would be labeled “1_7.15.96a”. The sample was catalogued in an Excel 2003 worksheet. Data for each individual included: reference number, date of birth, date of fracture, date of subsequent radiographs, fracture location, fiacture diagnosis, age at time of fracture, days of healing (calculated as the number of days between fracture occurrence and subsequent radiograph), and other comments. Other comments included information concerning reductions or surgical interventions. Once digitized and cataloged, the radiographs were examined for evidence of fi‘acture healing. Examination was performed by opening each image individually in Adobe Photoshop CS2. The fracture healing was categorized into six stages, modified from Hufnagl 2005. The characteristics of each of the stages were as follows: Stage 1 - No healing: sharp fracture lines, absence of bridging and callus formation. Stage 2 — Granulation: beginning of resorption along fracture line, “fluffy” callus formation, blurring of fi'acture line, absence of a complete mature callus 37 Stage 3 — Callus: mature callus formation around fracture site; callus bulges over site and demonstrates a radiopaque appearance, fracture line visible but may be blurred Stage 4 — Bridging: fracture gap is connected across the fracture site in some, but not all areas (less than 50%), blurring of the fracture line, callus may still be present Stage 5 — Clinical Union: fracture line is significantly blurred; fracture line is connected in most areas (more than 50%), callus presence minimal Stage 6 — Completion: No evidence of fracture line, callus presence minimal or not observable. Each radiograph was assigned a stage and this information was added to the Excel worksheet. If there was any uncertainty between two stages, the radiograph was assigned to the earlier stage. If the radiograph was not clear enough to identify a stage, it was excluded fi'om the study. Statistical Analyses Stages A database including the days of healing and the stage scored for each radiograph was created for statistical analysis. All statistics were calculated using the Data Analysis application in Excel 2003. One-way Analysis of Variance (ANOVA) was performed to determine if there was a significant difference in the healing time among each of the six stages. One-way AN OVA is typically used when comparisons of the mean need to be made among three or more independent groups and one independent variable has been 38 manipulated (Salkind 2007). An F-ratio, comparing the between-group variability and the within-group variability, is compared to the F-critical value to determine the significance of the data. In this instance, AN OVA was used to compare the mean days of healing (dependent variable) among each of the stages (independent variable) to determine whether the stages would be useful for separating the sample. In addition to AN OVA, the Bonferroni correction, a post hoc test of multiple comparison, was added to determine where inequalities were present in the samples (Sirkin 2006). AN OVA was used to see if there was a statistically significant difference among the stages, and the Bonferroni correction was used to identify where the difference or differences are occurring. Age A database including the days of healing, the stage of healing, and the age of each individual was created for statistical analysis. All statistics were calculated using the Data Analysis application in Excel 2003. The statistics were used to determine if there was a significant difference in the time of healing among the three age groups (0-1 years old, 2- 3 years old, and 4-5 years old) at each of the stages; therefore, enabling the researcher to determine if differences among the healing times of the age groups are present and at what point in the healing process, earlier verse later, they occurred. For each of the six stages, One-way Analysis of Variance (ANOVA) with Bonferroni correction was performed for the three age groups. In this instance, AN OVA was used to compare the mean days of healing (dependent variable) in each stage among the three age groups (independent variable). Additional AN OVA with Bonferroni correction analyses where 39 performed grouping the stages into three groups (Stages 1-2, Stages 3-4, and Stages 5-6) and into two groups (Stages 1-3 and Stages 4-6). In addition to the original three age groups, the sample was also divided into two age groups: individuals from birth to two years old and individuals between three and five years old. The statistics were used to determine if there was a significant difference in the time of healing between the two age groups at each of the stages. For each of the six stages, Welch’s t-test, used for unequal sample size and unequal variance, was performed for the two age groups. An independent, unpaired t-test is used to examine whether there is a difference between the means of two independent groups (Salkind 2007). The t-test allowed the mean days of healing (dependent variable) to be compared between the two age groups (independent variable) for each of the stages. Fracture Location A second database including the days of healing, the stage of healing, and the fracture location was created for statistical analysis. All statistics were calculated using the Data Analysis application in Excel 2003. The statistics were used to determine if there was a significant difference in the time of healing between the two fracture locations (forearm and leg) at each of the stages; therefore, enabling the researcher to determine if differences in healing times between the fracture locations exist and at what point in the healing process, earlier verse later, the differences occurred. For each of the six stages, Welch’s t-test was performed for the two fracture locations. The t—test allowed the mean days of healing (dependent variable) to be compared between the two fiacture location groups (independent variable) for each of the stages. Stages were re-categorized 40 into three groups (Stages 1-2, Stages 3-4 and Stages 5-6) and into two groups (Stages 1-3 and Stages 4-6). T-tests were also used when assessing these alternate stage combinations. 4] CHAPTER 7: RESULTS Radiographic Atlas of Pediatric Fracture Healing A main objective of this research was to develop a set of images that demonstrated the radiographic features evident in pediatric fracture healing. Several individuals will be discussed and illustrated here. Additional examples of each stage are included in Appendix A (Figures 15-33). The first example, Individual #10, was a five year old who suffered a forearm fracture. Figures 6-10 demonstrate the radiographic healing process. Figure 6 — Individual #10: Forearm fracture, Stage 1, 0 days healing 42 Figure 7 — Individual #10: Forearm fracture, Stage 1, 3 days healing Figure 8 — Individual #10: Forearm fracture, Stage 2, 17 days healing 43 Figure 9 — Individual #10: Forearm fracture, Stage 3, 30 days healing Figure 10 — Individual #10: Forearm fracture, Stage 3, 46 days healing A second example is Individual #107, a five year old, who suffered a fracture to the leg. Figures 11-14 demonstrate the radiographic healing process. Figure 11 — Individual #107: Leg fracture, Stage 1, 6 days healing Figure 12 — Individual #107: Leg fracture, Stage 2, 11 days healing 45 Figure 13 — Individual #107: Leg fracture, Stage 2, 28 days healing Figure 14 - Individual #107: Leg fracture, Stage 3, 49 days healing 46 Stage Analysis A statistical aim of this research was to determine the usefulness of categorizing radiographs by the stages of healing presented. It was expected that the mean healing times would increase across the stages. This expectation was confirmed; all differences demonstrated among the mean healing times for each stage indicated increased healing time with later stages, with Stage 1 showing the shortest mean healing time and Stage 6 indicating the longest mean healing time. The mean healing time in Stage 1 was 3.3 days, with a standard deviation of 3.4. The mean healing time in Stage 2 was 21.0 with a standard deviation of 10.5. The mean healing time in Stage 3 was 38.4 days, with a standard deviation of 13.4. The mean healing time in Stage 4 was 43.9 days, with a standard deviation of 15.2. The mean healing time in Stage 5 was 65.2 days, with a standard deviation of 48.2. The mean healing time in Stage 6 was 313.3 days, with a standard deviation of 235.7. These results are summarized in Table 2. Table 2 — Stages and Healing Times Mean healing time Range in healing time Standard STAGE (days) (days) Deviation Stage 1 3.3 0-14 3.4 Stage 2 21.0 4-50 10.5 Stage 3 38.4 15—75 13.4 Stage 4 43.9 24-93 15.2 Stage 5 65.2 24-156 48.2 Stage 6 313.3 42-750 235.7 47 Due to the clinical purpose of the radiographs, the images analyzed in this study may have been taken at any point in the stage in which they were categorized. The impossibility of knowing the exact time in the healing process when each stage is reached limits the utility of looking at the ranges when assessing healing time. Individuals may have demonstrated healing times on either side of the mean healing time, but the range of possible values for each stage may not have been depicted by the sample. In order to apply such data to other individuals, the standard deviations, indicative of the dispersion of the data, should be taken into account. Analysis of Variance (AN OVA) was performed to determine if statistical differences in the mean healing time were present among the stages of healing (Appendix B, Table 3). An F value of 100.08 and a p value of less than 0.0001 were obtained. These results indicate that the differences in the healing time among the stages were statistically significant at the 0.0001 level and null hypothesis 1 should be rejected. To determine the extent of the difference in mean healing time, the Bonferroni correction was added to the ANOVA analysis. At a 95% confidence interval, Stage 1 was statistically significant from all other stages. Stage 2 was statistically significant from Stages 1, 4, 5 and 6, but was not statistically significant from Stage 3. Stage 3 was statistically significant from Stages 1 and 6, but not statistically significant from Stages 2, 4 and 5. Stage 4 was statistically significant from Stages 1, 2 and 6, but not statistically significant from Stages 3 and 5. Stage 5 was statistically significant from Stages 1, 2 and 6, but not statistically significant from Stages 3 and 4. Stage 6 was statistically significant from all other stages. The results indicate statistical differences were demonstrated between some, but not all stages (Appendix B, Table 3). The variations in mean healing time were most clearly 48 defined at the beginning and end of the healing process, as evident from Stages 1 and 6 demonstrating statistical significance from all other stages. Age Analysis Another goal of the research was to determine the influence of the patient’s age on the rate of the healing process. Three age groups (0-1 years, 2-3 years, and 4-5 years old) were compared at each of the six stages using AN OVA. It was expected that younger individuals would have shorter mean healing times than older individuals. This expectation was confirmed at some, but not all, stages. At Stage 1, an F-value of 3.67 and p value of 0.0292 were obtained, indicating the mean healing times were statistically significant among the age groups at the 0.05 level. The Bonferroni correction indicated that the mean healing time of individuals ages 0-1 year old was statistically significant fi'om the mean healing time of individuals ages 4-5 years old at the 0.05 level with the younger individuals having a shorter mean healing time. Individuals ages 0-1 years and 2-3 years and individuals 2-3 years and 4-5 years were not statistically significant from one another (Appendix B, Table 4). At Stage 2, an F-value of 0.55 and a p value of 0.5776 were obtained, indicating the mean healing times were not statistically significant among the age groups (Appendix B, Table 5). At Stage 3, an F-value of 0.61 and a p value of 0.5459 were obtained, indicating the mean healing times were not statistically significant among the age groups (Appendix B, Table 6). At Stage 4, an F-value of 0.29 and a p value of 0.7537 were obtained, indicating the mean healing times were not statistically significant among the age groups (Appendix B, Table 7). Due to the small amount of radiographs demonstrating healing in Stages 5 and 6, the healing times were 49 combined into one group. At Stages 5-6, an F-value of 7.11 and a p value of 0.0082 were obtained, indicating the mean healing times were statistically significant among the age groups. The Bonferroni correction indicated that the mean healing time of individuals ages 0-1 years was statistically significant from the mean healing time of individuals ages 4-5 years at the 0.05 level. Additionally, the mean healing time of individuals ages 2-3 years was statistically significant from the mean healing times of individuals ages 4-5 years at the 0.05 level. In both of these cases, the younger group had a shorter mean healing time. The mean healing times of individuals 0-1 year and individuals 2-3 years were not statistically significant form one another (Appendix B, Table 8). These results indicate age influenced the mean healing time at Stage 1 and Stages 5-6 (Appendix B, Table 9). Null hypothesis 2 may be rejected as differences were seen in the mean healing times among the three age groups. Null hypotheses 2a, 2e and 2f may be rejected at the 95% confidence level, whereas null hypotheses 2b, 2c and 2d should be accepted. When statistically significant results were present, younger individuals demonstrated a shorter mean healing time than older individuals. Additionally, statistically significant differences arose at the beginning and end of the healing process. To further assess the influence of age on the healing process and to expand sample size, the stages were grouped into sets of two, dividing the healing process into beginning (Stages 1-2), middle (Stages 3-4) and end (Stages 5-6). Three age groups (0-1 years, 2-3 years, and 4-5 years old) were compared at each of these three stages using ANOVA. At Stages 1-2, an F -va1ue of 2.18 and p value of 0.1 156 were obtained, indicating the mean healing times were not statistically significant among the age groups (Appendix B, Table 10). At Stages 3-4, an F -value of 0.52 and a p value of 0.5974 were 50 obtained, indicating the mean healing times were not statistically significant among the age groups (Appendix B, Table 11). Stages 5-6 were previously discussed due to small sample size (Appendix B, Table 8). The results of combining the stages into three groups indicate age influenced the mean healing time only at Stages 5-6 (Appendix B, Table 12). Stages were also grouped into a beginning (Stages 1-3) and end (Stages 4-6) of the healing process. Three age groups (0-1 years, 2-3 years, and 4-5 years old) were compared at each of these two stages using ANOVA. At Stages 1-3, an F -value of 0.84 and p value of 0.4330 were obtained, indicating the mean healing times were not statistically significant among the age groups (Appendix, Table 13). At Stages 4-6, an F- value of 1.62 and a p value of 0.2093 were obtained, indicating the mean healing times were not statistically significant among the age groups (Appendix B, Table 14). These results indicate a limited role of age in the fracture healing process (Appendix B, Table 15). Due to the small sample size of later stages, age was also assessed by grouping the sample into two age groups instead of the original three age groups. Individuals age 0-2 years old were compared with individuals age 3—5 years old through a t-test at each of the six stages. At Stage 1, a t-value of -2.35 and a t-critical value of 1.66 were obtained, indicating the mean healing times were statistically significant between the age groups at the 0.01 level. Individuals ages 0-2 years had a shorter mean healing time than older individuals (Appendix B, Table 16). At Stage 2, a t-value of 0.128 and a t-critical value of 1.67 were obtained, indicating the mean healing times were not statistically significant between the age groups (Appendix B, Table 17). At Stage 3, a t-value of -0.40 and a t- critical value of 1.69 were obtained, indicating the mean healing times were not 51 statistically significant between the age groups (Appendix B, Table 18). At Stage 4, a t- value of 0.27 and a t-critical value of 1.77 were obtained, indicating the mean healing times were not statistically significant between the age groups (Appendix B, Table 19). At Stage 5, a t-value of -5.97 and a t-critical value of 2.92 were obtained, indicating the mean healing time of 0-2 year olds was shorter than the mean healing time of 3-5 year olds. This finding was statistically significant at the 0.01 level (Appendix B, Table 20). At Stage 6, a t-value of -2.53 and a t-critical value of 2.13 were obtained, indicating the mean healing time of 0-2 year olds was shorter than the mean healing time of 3-5 year olds. This finding was statistically significant at the 0.05 level (Appendix B, Table 21). These results indicate age influenced the mean healing time at Stage 1, Stage 5 and Stage 6 (Appendix B, Table 22). Again, statistically significant differences were present at the beginning and end of the healing process. As previously assessed with the three age groups, the healing stages were also divided into a beginning (Stages 1-2), middle (Stages 3-4) and end (Stages 5-6). Individuals age 0-2 years old were compared with individuals age 3-5 years old through a t-test at each of these three stages. At Stages 1-2, a t-value of -1.67 and a t-critical value of 1.66 were obtained, indicating the mean healing times were statistically significant between the age groups at the 0.05 level. Individuals ages 0-2 years had a shorter mean healing time than older individuals (Appendix B, Table 23). At Stages 3-4, a t-value of - 0.14 and a t-critical value of 1.68 were obtained, indicating the mean healing times were not statistically significant between the age groups (Appendix B, Table 24). At Stages 5- 6, a t-value of -2.63 and a t-critical value of 1.89 were obtained, indicating the mean healing time of 0-2 year olds was shorter than the mean healing time of 3-5 year olds. 52 This finding was statistically significant at the 0.05 level (Appendix B, Table 25). These results indicate age influenced the mean healing time at the beginning (Stages 1-2) and end (Stages 5-6) of the healing process (Appendix B, Table 26). The original six stages were also split into two groups: beginning (Stages 1-3) and end (Stages 4-6) of the healing process. Individuals age 0-2 years old were compared with individuals age 3-5 years old through a t-test at each of these stages. At Stages 1-3, a t-value of -1.41 and a t-critical value of 1.65 were obtained, indicating the mean healing times were not statistically significant between age groups (Appendix B, Table 27). At Stages 4-6, a t-value of -l .68 and a t-critical value of 1.69 were obtained, indicating the mean healing times were not statistically significant between age groups (Appendix B, Table 28). These results indicate that age doe not influence the healing rate throughout the healing process (Appendix B, Table 28). Fracture Location Analysis A final statistical goal of the research was to determine the influence of the fracture location on the rate of the healing process. Two fracture locations, forearm and leg, were compared at each of the six stages through t-tests. It was expected that forearm fractures would have a shorted mean healing time when compared to leg fractures. At Stage 1, a t-value of 1.10 and a t-critical value of 1.66 were obtained, indicating the mean healing times were not statistically significant between the fracture locations (Appendix B, Table 30). At Stage 2, a t-value of -3.95 and a t-critical value of 1.67 were obtained, indicating the mean healing time of forearm fractures was shorter than the mean healing time for leg fractures. This finding was statistically significant at the 0.01 level 53 (Appendix B, Table 31). At Stage 3, a t-value of -l.72 and a t-critical value of 1.68 were obtained, indicating the mean healing time of forearm fractures was shorter than the mean healing time for leg fractures. This finding was statistically significant at the 0.05 level (Appendix B, Table 32). At Stage 4, a t-value of 0.17 and a t-critical value of 1.81 were obtained, indicating the mean healing times were not statistically significant between fracture locations (Appendix B, Table 33). At Stage 5, a t-value of -0.42 and a t-critical value of 2.35 were obtained, indicating the mean healing times were not statistically significant between fracture locations (Appendix B, Table 34). At Stage 6, a t-value of 0.09 and a t-critical value of 2.35 were obtained, indicating the mean healing times were not statistically significant between fracture locations (Appendix B, Table 35). These results indicate fracture location influenced the mean healing time at Stages 2 and 3 (Appendix B, Table 36). Null hypothesis 3 may be rejected due to the differences indicated between the mean healing times of forearm fracture and leg fractures. Null hypotheses 3b should be rejected at the 0.01 level, and null hypothesis 3c should be rejected at the 0.05 level. Null hypotheses 3a, 3d, 3e and 3f should be accepted. Additionally, when significant differences were found, forearm fiactures healed at an increased rate compared to leg fractures. The stages were combined into a beginning (Stages 1-2), middle (Stages 3-4) and end (Stages 5-6) of the healing process. The two fracture locations were compared at each of these three stages through t-tests. At Stages 1-2, a t-value of -2.59 and a t-critical value of 1.66 were obtained, indicating the mean healing times were shorter for individuals with forearm fractures than individuals with leg fractures. This finding was statistically significant at the 0.01 level (Appendix B, Table 37). At Stages 3-4, a t-value 54 of -l .04 and a t-critical value of 1.67 were obtained, indicating the mean healing times were not statistically significant between fracture locations (Appendix B, Table 38). At Stage 5-6, a t-value of -0.09 and a t-critical value of 1.80 were obtained, indicating the mean healing times were not statistically significant between fracture locations (Appendix B, Table 39). These results indicate fiacture location influenced the mean healing time at the beginning (Stages 1-2) of the healing process (Appendix B, Table 40). Additionally, when significant differences were found, forearm fractures healed at an increased rate compared to leg fractures. The original six stages were also split into two groups: beginning (Stages 1-3) and end (Stages 4-6) of the healing process. The two fracture locations were compared at each of these stages. At Stages 1-3, a t-value of —1.59 and a t-critical value of 1.65 were obtained, indicating the mean healing times were not statistically significant between fracture locations (Appendix B, Table 41). At Stages 4—6, a t-value of -0.20 and a t- critical value of 1.71 were obtained, indicating the mean healing times were not statistically significant between fracture locations (Appendix B, Table 42). These results indicate fracture location does not influence the mean healing rate during the fracture repair process (Appendix B, Table 43). 55 CHAPTER 8: DISCUSSION The six stages examined in this study demonstrate a timeline of fracture healing in children. The images of each of these stages present radiographic examples of the appearance of fracture lines, fiacture bridging, and fracture callus formation throughout the healing process. Future radiographs may be compared to these images and the stage descriptions to obtain an estimate of healing time in young children and infants from birth to five years old. Each of the six stages demonstrated an increased healing time when compared to the previous stages and overall the six stages were significantly different. When individually comparing stages, mean healing times were significantly different for most stages. Certain stages (Stages 2 and 3, Stages 3 and 4, Stages 3 and 5, and Stages 4 andS) did not demonstrate statistical significance from one another. It was expected that all stages would show differences from one another; therefore, the stages lacking statistical significance may have a commonality that prevented identifying each as a unique radiographic stage. These stages were all close together in the healing process and demonstrated an overlap in the ranges of healing times. The reasons the individual stages lacked significance could include natural variation in the fracture healing once a fracture healing has begun, thus indicating the importance of the initial fracture response when examining fracture healing. Altemately, the limited sample size, especially in later stages, may have prevented differences from being accurately depicted. A third reason for the lack of significance is that healing in the latter aspect of one stage would be difficult to differentiate from healing in the earlier part of the subsequent stages. With experience the researcher could identify, for instance, a late Stage 2. This may suggest that the stages 56 themselves were too broad, and it would be necessary to further narrow the stages based on additional radiographic features. Future research, with a larger sample size, could confirm or refute this possibility. Finally, the lack of significance may be due to other contributing factors influencing the healing process. Nonetheless, radiographic features present in the six stages should be considered when analyzing radiographic images, but an examiner should be cautious when employing a healing time estimate. Such discretion is particularly imperative when differentiating the middle stages of fracture healing and when an examiner has limited experience analyzing radiographs. The patient’s age did influence the fracture healing process and all statistically significant differences demonstrated increased mean healing time with increased age. When the sample was divided into three age groups, this finding was only significant at Stages 1 and 5-6. The difference indicated between the age groups, suggests that there may be a certain point in the development process where fracture healing may slow, possibility around the age of three. To further examine this result, age groups should be expanded and older children and adolescents included. The lack of statistical significance in the middle of the healing process may be a reflection of contributing factors or due to the original lack of significance between certain stages, as previously discussed. When the stages were grouped together into beginning, middle and end, statistically significant differences in the mean healing time were only present at Stages 5-6. By combing the stages into only two groups, no statistically significant differences were present. The decreased significance of the results when the stages were combined suggests the uniqueness of each fracture healing stage and furthers the hypothesis that an increased number of stages may lead to increased statistical significance. If the stages 57 were not unique categories, the regrouping of the stages may have increased the significance; instead the significance decreased. When the sample was divided into two age groups, age also influenced the healing process. This finding suggested that age influences healing at Stages 1, 5 and 6, though statistical significance was greater at the beginning of the healing process. Stages 2, 3 and 4 remained unaffected by age. While age differences in healing were expected at all stages, these stages are where the majority of healing in occurring. While increased age may prevent Stage 2 from beginning, as evident by the increased healing times in older individuals in Stage 1, age may not play an active role in the osseous reaction characteristic of Stage 2, the callus formation of Stage 3 or the bridging of the callus in Stage 4. Another possibility is a certain factor, unrelated to age, may be delaying or speeding up the osseous reaction that occurs in these stages. If there was a contributing factor present largely at Stages 2, 3 or 4, but not necessary at other stages, it could prevent the influence of age being demonstrated at this time in the healing process. Alternatively, this finding may be a reflection of the original significance of the stages. When healing stages were combined, the significance of the results declined. With beginning (Stages 1-2), middle (Stages 3-4) and end (Stages 5-6) stages, the results were still significant at the beginning and end of the healing process, but at lower confidence levels. When the stages were divided into two groups, confidence levels were lowered even more though still suggesting age may be a factor in the healing times. Once again, this finding confirmed the uniqueness of the stages, as more confidence was expressed in the statistically significant differences found when analyzing the original six stages. 58 To completely understand the influence of age in the fracture healing process, it is also necessary to examine the rates evident in adult fracture healing. Hufnagl (2005) used similar stages to assess a sample that ranged in age from two to 93 years. Using comparable stages, the mean healing times were as follows: Stage 1: 0.22 days; Stage 2: 22.37 days; Stage 3: 79.42 days; Stage 4: 116.96 days; Stage 5: 124.20 days; and Stage 6: 260.86. Hufiragl’s sample of 62 individuals included three equal age groups (2-10, 11—45, and 45 and older) with results indicating statistically significant differences among the age groups. It can be assumed that the mean healing times given would have been skewed towards individuals over the age of five. Comparing such healing times to the present study demonstrates some differences. Stage 1 and 2 demonstrated healing times within a couple days of each other. Stages 3, 4 and 5 were shortened by approximately one half in the present study of young children, whereas Stage 6 demonstrated a longer mean healing time. Stages 3, 4 and 5 may be demonstrating the stages in fiacture repair where age is most influential when comparing adults to children. When looking more precisely at children in the present study, differences were found earlier in the healing process. Additionally, while Stage 6 would demonstrate a deviation fiom expectation, in both studies Stage 6 was the most limited in number of individuals. In this regard, Stage 6 warrants further examination when comparing across samples and methodologies. Additionally, more samples of all ages should be examined in a similar manner to obtain accurate comparisons across certain groups. Fracture location also influenced the healing time in the sample examined. This finding was evident at Stages 2: Granulation and Stage 3: Mature Callus. When location did affect the healing time, forearm fi’actures healed faster then leg fractures. While it was 59 expected such a finding would be consistent across the stages, there are several reasons why the mean healing time in Stages 2 and 3 may have been influenced by the fiacture location. Stages 2 and 3 are the first stages where osseous reaction in occurring. Fracture location may be a particularly important factor for the initiation of fracture healing, with diminished impact after healing has begun. Additionally, the other stages may be more likely to encounter other contributing effectors. For instance, another important factor cited as impacting healing time is mobility. During the beginning stages of fiacture repair, mobility may be limited due to discomfort or internal or external stabilization. In later stages, mobility would increase and could become more influential in the fracture healing rate. Furthermore, the age of an individual may be an indirect factor. While in adults there may be significant differences in the mobility of upper and lower limbs when injury is sustained, these variations in movement may not be as pronounced in young children and infants. Additionally, in adults the vascularity of bone is decreased when compared to children (Odgen 2000). This difference, while obviously differentiating children from adults, may also influence the effects of fracture location on healing time. For instance, the tibia is known for its long healing times; a feature that may be linked to the diminished vascularity of the bone. With children’s increased vascularity, the tibia may heal significantly faster in children compared to adults, but when comparing children with children the expected difference may be diminished. At the same time, fracture location did impact healing time in these children, demonstrating that fracture location may impact healing rates regardless of patient age. It is important to realize the connection between fracture location and age, as fracture location may demonstrate an increased impact at a certain point in the development process. 60 Several aspects of the present study warrant further examination. The limited sample size of radiographs in later stages of healing was problematic. Radiographs are most commonly used and examined at the beginning of the fracture healing process. Once a patient feels better, he or she may not return for subsequent radiographs (Ogden 2000). Additionally, once significant healing is shown, it may not be necessary to continually radiograph the fracture site. Overall, the need for radiographs is determined on a clinical basis which may not be conducive to research interests. The original intent of the radiographs should be acknowledged as a limitation of the study. Stage 6 may have led to false confidence in the statistical differences between Stage 5 and 6. Any radiograph examined after healing had taken place would have been categorized as a Stage 6. In other words, any radiograph, whether taken days or years later, after Stage 5 would be a Stage 6. There is no limit to the end of Stage 6, so the data would be more likely to indicate statistically significant differences if radiographs were taken after an individual had previously reached Stage 6. A remedy for this dilemma in future research may be to limit the days healing for radiographs examined, but acknowledge that Stage 6 would continue indefinitely. Radiograph quality and the presence of external stabilization (casts), especially around the beginning of the healing process limited the ability to accurately categorize the sample into stages. If external stabilization or radiograph quality limited the ability to see a stage it was excluded, but if the researcher was able to identify whether it was either of two stages, the radiograph was classified as the earlier of the stages. For instance, what was identified as a late Stage 2/early Stage 3 would have been classified as a Stage 2. Therefore, an early Stage 3, obscured by casting material, may have been incorrectly 61 identified as a Stage 2. In future research, a sample devoid of external stabilization would be ideal, though such a sample would be difficult to gather due to the clinical need for fracture stabilization. Additionally, in a real world situation, a fracture in the beginning of the healing process would likely be casted. The limitation of external stabilization in radiographs should be acknowledged as a limitation of this research. Another potential concern for the present research is the possibility of other contributing direct or indirect factors influencing the rate of the fracture healing process. Of particular concern for the present research would be the type of fiacture encountered. While not a goal of this research, the type of fi'acture should be considered when assessing healing time in future research. When examining the ranges of the stages in the present study, the fractures with healing times at the beginning of the range tended to be incomplete, particularly torus, fractures. An incomplete fracture would be less traumatic than a complete fracture, and it is possible this factor was influencing the mean healing times examined when comparing ages and fracture location. In a sample of children, it is particularly important to determine the influence of incomplete fractures as they are a more common occurrence in this age group. Finally, while unusual instances of fracture repair were limited by the exclusion of co-morbidity, there may have been other factors or medical conditions which the researcher was not aware of that may have influenced healing rates. Great significance should not be placed on one individual demonstrating a delayed or increased healing rate. 62 CHAPTER 9: CONCLUSION Fracture healing can demonstrate a unique set of radiographic features that can be monitored throughout the healing process. The fracture repair process can be influenced by a number of factors. The goal of the present study was twofold. First, the research aimed to identify a set of radiographic stages of healing for infants and young children. A set of six radiographic stages of fracture healing was developed based on key radiographic features and past studies. A second goal was to determine how fi'acture location and patient age may influence the healing times of these radiographic stages. A sample of 107 individuals and 294 radiographs were examined to meet these goals. The sample consisted of forearm and leg fractures in children from birth to age five. The sample was separated into three age groups: birth to one year old, two to three years old, and four to five years old. Each radiograph was then placed into one of the six radiographic stages of fracture healing. Unpaired t-tests were used to compare fracture location at each of the six stages and Analysis of Variance (ANOVA) was used to compare patient age at each of the stages. These tests identified how fracture location and patient age influenced the mean healing time at each radio graphic stage of fracture healing. It was expected that the stages used would demonstrate increased healing time with later stages. While this finding was confirmed, stages in the middle of the healing process overlapped in their ranges and had limited statistical significance. The stages were usefiil in categorizing the sample and demonstrate the utility of assessing radiographic features in the fi'acture healing process. The limited significance of certain stages from one another in the middle of the healing process suggest caution should be 63 used when estimating healing times. Additionally, future research should examine whether the radiographic stage of fracture healing may be refined into a larger number of more specific stages. Through the analysis, the present study identified patient age as a factor influencing the healing rate of fractures in children. The differences identified in the mean healing time among the age groups suggests that fracture healing occurs at an accelerated rate in younger individuals. While this finding was not acknowledged at all stages of healing, the beginning and end of the fracture repair process were identified as key instances where age may be involved. The middle of the fracture healing process, a time when a large amount of osseous repair is occurring, may not be influenced by age in children. Instead age may play more of a role in delaying the start of the healing, as evident by the influence of age at Stage 1. Age may also demonstrate an increased influence on the fracture healing process, and perhaps later in the process, when children are compared with adults. Fracture location was also identified as a factor involved in the rate of the repair of skeletal trauma. The variations in mean healing time between forearm and leg fractures indicated that forearm fractures heal at an accelerated rate. This finding was identified in Stages 2 and 3 of the healing process, and may indicate an increased role in the initiation and osseous reaction of fracture healing. Contributing factors, such as age and fiacture site mobility, may influence the effects of fracture location on the rate of the healing process. Additional analysis of both patient age and fracture location by combining the stages of healing also has implications for the radiographic stages of fracture healing. While statistically significant differences were still demonstrated when healing stages were grouped together, the level of confidence was reduced with combination, substantiating the uniqueness of each of the stages. In firture studies, the stages should not be combined, instead further separation should be encouraged. This thesis provides statistical evidence of patient age and fracture location impacting the fracture healing process. It also provides a method to assess pediatric fractures through radiographic analysis and estimate a time since injury. While this thesis supports the use of radiographic stages of fracture healing in young children and infants, more research is needed to confirm and reassess the implications of age and fracture location. Age and fracture location themselves may influence other factors in the healing process. For instance, consider other factors that may accompany age. In children, the types of skeletal trauma will differ with an increased prevalence of incomplete fiactures (Lewis 2007). The healing rates between complete and incomplete fractures would likely differ. Additionally, the connection between fracture location and age is important to understand, as certain age groups are more likely to suffer fractures in specific locations (Jones 1994). The present study attempts to address age and fiacture location in a broad sense, but if other factors in fracture healing can be identified a more precise timeline could be developed for radiographically assessing fractures. The use of radiographic fracture healing stages has implications for the field of forensic anthropology. Skeletal remains may be assessed through visual examination, but may also be radiographed to elicit more information on antemortem trauma. Increasingly, it is becoming important to approach trauma, especially in children, with a multifaceted, integrated methodology. To facilitate a complete understanding and examination of 65 childhood trauma, forensic anthropology must incorporate clinical literature from pediatric biology and radiography. The in-depth inquiries required to assess trauma in children result in a demand to incorporate research methods to gain as much information as possible. While challenges loom and create a daunting future for the research in childhood trauma, the knowledge to be gained through extensive examination is priceless. 66 APPENDIX A 67 Radiographic Atlas of Pediatric Fracture Healing Stage 1 — No healing: sharp fracture lines, absence of bridging and callus formation. Figure 15 — Individual #8: Age 1, Forearm fracture, 0 days healing Figure 16 — Individual #17: Age 4, Forearm fracture, 5 days healing 68 Figure 17 - Individual #92: Age 1, Leg fracture, 1 day healing Figure 18 — Individual #109: Age 5, Leg fracture, 0 days healing 69 Stage 2 - Granulation: beginning of resorption along fracture line, “fluffy” callus formation, blurring of fracture line, absence of complete mature callus. Figure 19 — Individual #14: Age 4, Forearm fracture, 27 days healing Figure 20 — Individual #74: Age 1, Forearm fracture, 7 days healing 70 Figure 21 — Individual #67: Age 2, Leg fracture, 54 days healing Figure 22 — Individual #75: Age 5, Leg fracture, 39 days healing 7l Stage 3 — Callus: mature callus formation around fracture site; callus bulges over site and demonstrates a radiopaque appearance, fracture line visible but may be blurred. Figure 23 — Individual #47: Age 5, Forearm fracture, 50 days healing Figure 24 — Individual #86: Age 1, Forearm fracture, 75 days healing 72 Figure 25 — Individual #98: Age 3, Leg fracture, 42 days healing Figure 26 - Individual #100: Age 5, Leg fracture, 40 days healing 73 Stage 4 - Bridging: fracture gap is connected across the fracture site in some, but not all areas (less than 50%), blurring of the fracture line, callus may still be present. Figure 27 — Individual #12: Age 3, Forearm fracture, 51 days healing Figure 28 — Individual #35: Age 5, Forearm fracture, 40 days healing 74 Figure 29 — Individual #26: Age 5, Leg fracture, 63 days healing 75 Stage 5 — Clinical Union: fracture line is significantly blurred; fracture line is connected in most areas (more than 50%), callus presence minimal. Figure 30 — Individual #7: Age 0, Forearm fracture, 49 days healing Figure 31 —- Individual #49: Age 3, Forearm fracture, 111 days healing 76 Stage 6 — Completion: No evidence of fracture line, callus presence minimal or not observable. Figure 32 — Individual #40: Age 5, Forearm fiacture, 418 days healing Figure 33 - Individual #1 15: Age 2, Leg fracture, 188 days healing 77 APPENDIX B 78 Table 3 — Analysis of Variance with Bonferroni Correction for Six Stages 79 l-way AN OVA 11 294 Groups n Mean SE Pooled SE SD STAGE 1 99 3.3 0.34 3.65 3.4 STAGE2 91 21.0 1.11 3.81 10.5 STAGE 3 58 38.4 1.76 4.77 13.4 STAGE 4 30 43.9 2.78 6.63 15.2 STAGE 5 9 65.2 16.07 12.11 48.2 STAGE 6 7 313.3 89.09 13.73 235.7 Mean Source of variation Sum squares DF square F statistic p Groups 6604644 5 1320929 100.08 <0.0001 Residual 3801112 288 1319.8 Total 10405756 293 Bonferroni Contrast Difference 95% Cl STAGE 1 V STAGE 2 -17.6 -333 to .20 (significant) STAGE 1 V STAGE 3 -351 -529 to -173 (significant) STAGE 1 V STAGE 4 -405 -63.0 to -18.1 (significant) STAGE 1 V STAGE 5 -61.9 -99.3 to -24.5 (significant) STAGE 1 V STAGE 6 -3100 -3520 to -267.9 (significant) STAGE 2 v STAGE 3 -175 -355 to 0.6 STAGE 2 V STAGE 4 -229 -455 to 03 (significant) STAGE 2 V STAGE 5 -443 -81.8 to -6.7 (significant) STAGE 2 V STAGE 6 -292.3 -334.5 to 2501 (significant) STAGE 3 v STAGE 4 -5.4 -29.6 to 18.7 STAGE 3 v STAGE 5 -26.8 -65.3 to 11.7 STAGE 3 V STAGE 6 —274.9 -317.9 to -231.8 (significant) STAGE 4 v STAGE 5 -214 -62.2 to 19.5 STAGE 4 V STAGE 6 -269.4 -314.6 to -2243 (significant) STAGE 5 V STAGE 6 -248.1 -3023 to -1939 (significant) Table 4 — Analysis of Variance with Bonferroni Correction for Three Age Groups with Six Stages: Stage 1 l-way ANOVA n | 99 Pooled STAGE 1 11 Mean SE SE SD 0-1 30 2.4 0.54 0.61 3.0 2-3 24 2.7 0.57 0.68 2.8 4-5 45 4.3 0.57 0.50 3.8 Source of Sum Mean F variation squares DF square statistic J) STAGE 1 81.7 2 40.9 3.67 0.0292 Residual 1069.9 96 1 l .1 Total 1151.7 98 Bonferroni Contrast I Difference 95% CI 0-1 v 2-3 -0.3 -2.5 to 1.9 0-1 v 4-5 -1.9 -3.9 to -0.0 (significant) 2-3 v 4-5 -1.6 -3.7 to 0.4 Table 5 - Analysis of Variance for Three Age Groups with Six Stages: Stage 2 1-way ANOVA n l 91 Pooled STAGE 2 n Mean SE SE SD 0-1 17 19.9 2.61 2.57 10.8 2-3 25 22.8 1.91 2.12 9.6 4-5 49 20.4 1.58 1.51 11.0 Source of Sum Mean F variation squares DF square statistic p STAGE 2 124.1 2 62.1 0.55 0.5776 Residual 9890.8 88 112.4 Total 10014.9 90 Bonferroni Contrast | Difference 95% CI 0-1v 2-3 -3.0 -11.1 to 5.2 0-1 v 4-5 -0.5 -7.8 to 6.8 2-3 v 4-5 2.5 -3.9 to 8.8 80 Table 6 - Analysis of Variance with Bonferroni Correction for Three Age Groups with Six Stages: Stage 3 l-way ANOVA n l 58 Pooled STAGE 3 11 Mean SE SE SD 0-1 16 36.4 3.89 3.38 15.6 2-3 14 36.6 4.14 3.62 15.5 4-5 28 40.5 2.10 2.56 11.1 Source of Sum Mean F variation squares DF square statistic p STAGE 3 224.1 2 112.1 0.61 0.5459 Residual 10070.1 55 183.1 Total 10294.2 57 Bonferroni Contrast Difference 95% Cl 0-1 v 2-3 -0.2 -12.4 to 12.0 0-1 v 4-5 -4.0 -14.5 to 6.4 2-3 v 4-5 -3.8 -14.8 to 7.1 81 Table 7 — Analysis of Variance with Bonferroni Correction for Three Age Groups with Six Stages: Stage 4 l-way AN OVA 11 I 30 Pooled STAGE 4 It Mean SE SE SD 0-1 5 47.4 11.51 6.97 25.7 2—3 10 41.2 3.56 4.93 11.3 4-5 15 44.5 3.63 4.03 14.1 Source of Sum Mean F variation squares DF square statistic p STAGE 4 138.9 2 69.5 0.29 0.7537 Residual 6564.5 27 243.1 Total 6703.5 29 Bonferroni Contrast Difference 95% CI 0-1 V 2-3 6.2 -15.6 to 28.0 0-1 v 4-5 2.9 -l7.6 to 23.5 2-3 v 4-5 -3.3 -19.5 to 13.0 82 Table 8 - Analysis of Variance with Bonferroni Correction for Three Age Groups with Six Stages: Stage 5-6 l-way ANOVA n l 16 Pooled STAGE 5-6 11 Mean SE SE SD 0-1 5 64.8 28.37 66.09 63.4 2-3 6 93.0 28.16 60.33 69.0 4-5 5 379.6 110.46 66.09 247.0 Source of Sum Mean F variation squares DF square statistic p STAGE 5-6 3103450 2 1551725 7.11 0.0082 Residual 2838980 13 21838.3 Total 5942430 15 Bonferroni Contrast Difference 95% CI 0-1 v 2-3 -28.2 -273.9 to 217.5 0-1 v 4-5 -314.8 -571.4 to -58.2 (significant) 2-3 v 4-5 -286.6 -532.3 to -40.9 (significant) Table 9 — Summary of Analysis of Variance for Three Age Groups with Six Stages and Mean Healing Times Mean Healing Time (days) Statistically Age 0-1 Age 2-3 Age 4-5 Significant Stage 1 0.05 2.4 2.7 4.3 Stage 2 Not significant 19.9 22.8 20.4 Stage 3 Not significant 36.4 36.6 40.5 Stage 4 Not significant 47.4 41.2 44.5 Stages 5-6 0.01 64.8 93.0 379.6 83 Table 10 — Analysis of Variance with Bonferroni Correction for Three Age Groups with 3 Stages: Stages 1-2 1-way ANOVA n | 190 Pooled STAGES 1-2 n Mean SE SE SD 0-1 47 8.7 1.59 1.70 10.9 2-3 49 13.0 1.77 1.66 12.4 4-5 94 12.7 1.20 1.20 11.6 Source of Sum Mean F variation squares DF square statistic J) STAGES 1-2 591.5 2 295.7 2.18 0.1156 Residual 25335.8 187 135.5 Total 25927.3 189 Bonferroni Contrast Difference 95% CI 0-1 v 2-3 -4.3 -10.0 to 1.5 0-1 v 4-5 -4.0 -9.0 to 1.0 2-3 v 4-5 0.3 -4.7 to 5.2 84 Table 11 — Analysis of Variance with Bonferroni Correction for Three Age Groups with 3 Stages: Stages 3-4 1-way ANOVA n I 88 Pooled STAGES 3-4 n Mean SE SE SD 0-1 21 39.0 4.01 3.12 18.4 2-3 24 38.5 2.82 2.92 13.8 4-5 43 41.9 1.86 2.18 12.2 Source of Sum Mean F variation squares DF square statistic p STAGES 3-4 211.8 2 105.9 0.52 0.5974 Residual 17370.1 85 204.4 Total 17581.9 87 Bonferroni _ Contrast Difference 95% CI 0-1 v 2-3 0.5 -9.9 to 10.9 0-1 v 4-5 —2.8 -12.1 to 6.5 2-3 v 4-5 -3.3 -12.2 to 5.6 Table 12 — Summary of Analysis of Variance for Three Age Groups with Three Stages and Mean Healing Times Mean Healing Time (days) Statistically Age 0-1 Age 2-3 Age 4-5 Significant Stages 1-2 Not significant 8.7 13.0 12.7 Stage 3-4 Not Sigrificant 39.0 38.5 41.9 Stages 5-6 0.01 64.8 93.0 379.6 85 Table 13 — Analysis of Variance with Bonferroni Correction for Three Age Groups with Two Stages: Stages 1-3 l-way ANOVA n l 248 Pooled STAGES 1-3 n Mean SE SE SD 0-1 63 15.7 2.16 2.09 17.2 2-3 63 18.2 2.06 2.09 16.4 4-5 122 19.1 1.48 1.50 16.4 Source of Sum Mean F variation squares DF square statistic p STAGES 1-3 461.7 2 230.8 0.84 0.4330 Residual 67336.3 245 274.8 Total 67798.0 247 Bonferroni Contrast Difference 95% CI 0-1 v 2-3 -2.5 -9.6 to 4.6 0-1 v 4-5 -3.3 -9.5 to 2.9 2-3 v 4-5 -0.8 -7.0 to 5.4 86 Table 14 — Analysis of Variance with Bonferroni Correction for Three Age Groups with Two Stages: Stages 4-6 1-way ANOVA n I 46 Pooled STAGES 4-6 n Mean SE SE SD 0-1 10 56.1 14.72 40.99 46.6 2-3 16 60.6 12.07 32.41 48.3 4-5 20 128.3 41.93 28.98 187.5 Source of Sum Mean F variation squares DF square statistic p STAGES 4-6 54517.5 2 27258.8 1.62 0.2093 Residual 7224604 43 16801.4 Total 776977 .9 45 Bonferroni Contrast Difference 95% CI to 0'1 V 2'3 -4.5 -134.7 125.6 0-1 v 4-5 -72.2 -197.2 to 52.9 2-3 v 4-5 -67 .6 -175.9 to 40.7 Table 15 — Summary of Analysis of Variance for Three Age Groups with Two Stages and Mean Healing Times Mean Healing Time (da S) Statistically Age 0-1 Age 2-3 Age 4-5 Significant Stages 1-3 Not significant 15.7 18.2 19.1 Stage 4-6 Not significant 56.1 60.6 128.3 87 Table 16 — T-test for Two Age Groups with Six Stages: Stage 1 0-2 3-5 Mean Variance Observations Hypothesized Mean Difference Df t Stat P(T<=t) one-tail t Critical one-tail P(T<=t) two-tail t Critical two-tail 2.428571429 3.98245614 8.787456446 13.08897243 42 57 0 96 -2.345619971 0.010526594 1.660882845 0.021053188 1.984985829 Table 17 - T-test for Two Age Groups with Six Stages: Stage 2 0—2 3-5 Mean Variance Observations Hypothesized Mean Difference Df t Stat P(T<=t) one-tail t Critical one-tail P(T<=t) two-tail t Critical two-tail 21 .17857143 20.87301587 109.1891534 113.9513569 28 63 0 53 0.127889339 0.449360289 1.6741 15993 0.898720577 2.005745046 Table 18 — T-test for Two Age Groups with Six Stages: Stage 3 0-2 3-5 Mean Variance Observations Hypothesized Mean Difference Df t Stat P(T<=t) one-tail t Critical one-tail P(T<=t) two-tail t Critical two-tail 37.4 38.97368421 229.9368421 159.269559 20 38 0 33 -0.397312082 0.346847799 1.692360456 0.693695598 2.03451691 88 Table 19 — T-test for Two Age Groups with Six Stages: Stage 4 0—2 3-5 Mean 45.1 43.25 Variance 376.5444444 173.25 Observations 10 20 Hypothesized Mean Difference 0 Df 13 t Stat 0.27183275 P(T<=t) one-tail 0.3950099 t Critical one-tail 1.770931704 P(T<=t) two-tail 0.7900198 t Critical two-tail 2.16036824 Table 20 — T-test for Two Age Groups with Six Stages: Stage 5 0-2 3-5 Mean 34.66666667 126.3333333 Variance 94.26666667 660.3333333 Observations 6 3 Hypothesized Mean Difference 0 Df 2 t Stat -5.969240478 P(T<=t) one-tail 0.01 346801 1 t Critical one-tail 2.91998731 P(T<=t) two-tail 0.026936023 t Critical two-tail 4.302655725 Table 21 — T-test for Two Age Groups with Six Stages: Stage 6 0-2 3-5 Mean 135.6666667 446.5 Variance 6610.333333 51499.66667 Observations 3 4 Hypothesized Mean Difference 0 Df 4 t Stat -2.531340198 P(T<=t) one-tail 0.032286269 t Critical one-tail 2.131846486 P(T<=t) two-tail 0.064572538 t Critical two-tail 2.776450856 89 Table 22 — Summary of T-tests for Two Age Groups with Six Stages and Mean Healing Times 2. 21 37. 45.1 34. 135. Table 23 — T—test for Two Age Groups with Three Stages: Stages 1-2 0-2 3-5 Mean 9.928571429 12.85 Variance 133.5455487 137.2714286 Observations 70 120 Hypothesized Mean Difference 0 Df 146 t Stat -1.672333075 P(T<=t) one-tail 0.048300164 t Critical one-tail 1.655357664 P(T<=t) two-tail 0.096600327 t Critical two-tail 1.976345629 Table 24 - T-test for Two Age Groups with Three Stages: Stages 3-4 0-2 3-5 Mean Variance Observations Hypothesized Mean Difference Df t Stat P(T<=t) one-tail t Critical one-tail P(T<=t) two-tail t Critical two-tail 39.96666667 40.448275 86 281.1367816 165.3393829 30 58 0 47 -0.137760693 0.445509027 1.677926775 0.891018055 2.01 1738616 90 Table 25 — T-test for Two Age Groups with Three Stages: Stages 5-6 0-2 3-5 Mean 68.33333333 309.2857143 Variance 4261.75 55257.57143 Observations 9 7 Hypothesized Mean Difference 0 Df 7 t Stat -2.634111956 P(T<=t) one-tail 0.016855294 t Critical one-tail 1.894577508 P(T<=t) two-tail 0.033710589 t Critical two-tail 2.36462256 Table 26 — Summary of T-tests for Two Age Groups with Three Stages and Mean Healing Times Mean H ' Time da tatisti Si ' 0-2 3-5 1-2 0.0 9. 3-4 Not 8' ° 40. 5-6 0.0 68. Table 27 - T-test for Two Age Groups with Two Stages: Stages 1-3 0—2 3-5 Mean 16.03333333 19.13291139 Variance 284.5269663 267 .033 1 775 Observations 90 1 5 8 Hypothesized Mean Difference 0 Df 1 80 t Stat -1.407229149 P(T<=t) one-tail 0.080541927 t Critical one-tail 1.653363597 P(T<fi) two-tail 0.161083855 t Critical two-tail 1.9732306] 91 Table 28 — T-test for Two Age Groups with Two Stages: Stages 4-6 0-2 3-5 Mean 56.10526316 112.2222222 Variance 2224.432749 26993.02564 Observations 19 27 Hypothesized Mean Difference 0 Df 32 t Stat -1.679202614 P(T<#) one-tail 0.05142628 t Critical one-tail 1.693888407 P(T<=t) two-tail 0.102852561 t Critical two-tail 2.036931619 Table 29 — Summary of T-tests for Two Age Groups with Two Stages and Mean Healing Times Mean H ' Time tatisti Si ' cant 0-2 3-5 1-3 Not Si ' 16. 4-6 Not Si ' 56.1 Table 30 — T—test for Fracture Location with Six Stages: Stage 1 forearm leg Mean 3.596774194 2.864864865 Variance 13.81835008 8.231231231 Observations 62 37 Hypothesized Mean Difference 0 Df 91 t Stat 1.096756703 P(T<=t) one-tail 0.137820812 1 Critical one-tail 1.661771876 P(T<=t) two—tail 0.275641624 t Critical two-tail 1.986377356 92 Table 31 — T-test for Fracture Location with Six Stages: Stage 2 forearm leg Mean 17.32692308 25.82051282 Variance 68.38122172 129.4669366 Observations 52 39 Hypothesized Mean Difference 0 Df 66 t Stat -3.94530882 P(T<=t) one-tail 9.78476E-05 t Critical one-tail 1.668270215 P(T<=t) two-tail 0.000195695 t Critical two-tail 1.996563697 Table 32 — T-test for Fracture Location with Six Stages: Stage 3 forearm leg Mean 36.53846154 42.31578947 Variance 205.4129555 114.5614035 Observations 39 19 Hypothesized Mean Difference 0 Df 46 tStat -1.7189141 P(T<=t) one-tail 0.046176968 t Critical one-tail 1.678658919 P(T<=t) two-tail 0.0923 53935 t Critical two-tail 2.012893674 Table 33 — T-test for Fracture Location with Six Stages: Stage 4 forearm leg Mean 44.13043478 43 Variance 238.5731225 241 .3333333 Observations 23 7 Hypothesized Mean Difference 0 Df 10 t Stat 0.168798835 P(T<=t) one-tail 0.434660161 t Critical one-tail 1.812461505 P(T<=t) two-tail 0.869320322 t Critical two-tail 2.228139238 93 Table 34 — T-test for Fracture Location with Six Stages: Stage 5 forearm leg Mean 59.16666667 77.33333333 Variance 1716.566667 4677.333333 Observations 6 3 Hypothesized Mean Difference 0 Df 3 t Stat -0.42291479 P(T<=t) one-tail 0.350421 109 t Critical one-tail 2.353363016 P(T<=t) two-tail 0.700842217 t Critical two-tail 3.182449291 Table 35 — T-test for Fracture Location with Six Stages: Stage 6 forearm leg Mean 3 17.4 303 Variance 76650.8 26450 Observations 5 2 Hypothesized Mean Difference 0 Df , 3 t Stat 0.085215813 P(T<=t) one-tail 0.46872914 t Critical one-tail 2.3 5336301 6 P(T<=t) two-tail 0.93745 8281 t Critical two-tail 3.182449291 Table 36 — Summary of T-tests for Fracture Location with Six Stages and Mean Healing Times tatistically Not 8' 0.01 0. Not Si Not S' Not S' 94 Table 37 — T-test for Fracture Location with Three Stages: Stages 1-2 forearm leg Mean 9.859649123 14.64473684 Variance 85.5022512 202.9521053 Observations 1 14 76 Hypothesized Mean Difference 0 Df 117 tStat 2587311844 P(T<=t) one-tail 0.005448454 t Critical one-tail 1.657981556 P(T<=t) two-tail 0.010896909 t Critical two-tail 1.98044745 Table 38 — T-test for Fracture Location with Three Stages: Stages 3-4 forearm leg Mean 39.35483871 42.5 Variance 227.6753041 140.5 Observations 62 26 Hypothesized Mean Difference 0 Df 59 t Stat -1.043986774 P(T<=t) one-tail 0.150375123 t Critical one-tail 1.671091923 P(T<=t) two-tail 0.300750247 t Critical two-tail 2.000997483 Table 39 -— T-test for Fracture Location with Three Stages: Stages 5-6 forearm leg Mean 176.5454545 167.6 Variance 49705.27273 24228.8 Observations 11 5 Hypothesized Mean Difference 0 Df 11 t Stat 0.092440427 P(T<fi) one-tail 0.4640051 t Critical one-tail 1.795883691 P(T<fi) two-tail 0.928010201 t Critical two-tail 2.200986273 95 Table 40 — Summary of T-tests for Fracture Location with Three Stages and Mean Healing Times Mean Healin Time (days) Statistically Forearm Leg Significant Stage 1-2 0.01 9.9 14.6 Stage 3-4 Not Significant 39.4 42.5 Stage 5-6 Not Significant 176.5 167. Table 41 — T-test for Fracture Location with Two Stages: Stagesl-3 forearm leg Mean 16.66013072 20.17895 Variance 250.9889921 307.6804 Observations 153 95 Hypothesized Mean Difference 0 Df 184 t Stat -1.593025337 P(T<=t) one-tail 0.056435453 t Critical one-tail 1.653177151 P(T<=t) two-tail 0.112870906 t Critical two-tail 1.972939572 Table 42 — T-test for Fracture Location with Two Stages: Stages 4-6 forearm leg Mean 86.97058824 94.91667 Variance 19174.9385 13058.63 Observations 34 12 Hypothesized Mean Difference 0 Df 23 t Stat -0.195489365 P(T<fi) one-tail 0.423363309 t Critical one-tail 1.713870006 P(T<=t) two-tail 0.846726619 t Critical two-tail 2.068654794 96 Table 43 — Summary of T-tests for Fracture Location with Two Stages and Mean Healing Times Mean Healin Time (days) Statistically Forearm Leg Significant Stages 1-3 Not Significant 16.7 20.2 Stages 4-6 Not Significant 87.0 94.9 97 BIBLIOGRAPHY 98 BIBLIOGRAPHY Armstrong PF, VE Joughin, HM Clarke, RB Willis (2003) Fractures of the Forearm, Wrist and Hand. In Skeletal Trauma in Children. Green NE and MF Swiontkowski (eds.) Philadelphia, PA: WB Saunders Company. Auringer ST (2002) Special Considerations in Children. In Radiology of Skeletal Trauma. Rogers LF (ed.). Vol. 1, 3rd ed. New York: Churchill Livingstone. Baitner AC, A Perry, FD Lalonde, TP Bastrom, J Pawelek, and PO Newton (2007). The healing forearm fracture: A matched comparison of forearm refracture. Journal of Pediatric Orthopaedics 27(7):743-747. Blokhais TJ, de Bruine JH, Bramer JA, den Boer FC, Bakker FC, Patka P, Haarimon HJ, Manolui RA (2001). The Reliability of Plain Radiography in Experimental Fracture Healing. Skeletal Radiology 30 (3): 151-156. Brogden, BG (1998). Forensic Radiology. Boca Raton: CRC Press. Caffrey J (1946) Multiple fiactures in the long bones of infants suffering from chronic subdural hematoma. American Journal of Roentgenology 56:163-173. Chung KC and SV Spilson (2001) The frequency and epidemiology of hand and forearm fi'actures in the United States. The Journal of Hand Surgery 26(5): 908-915. Cox TD and A Sonin (2002) The Elbow and Forearm. In Radiology of Skeletal Trauma. Rogers LF (ed.). Vol. 2, 3rd ed. New York: Churchill Livingstone. Cumming WA (1979) Neonatal Skeletal Fractures. Birth Trauma or Child Abuse? Journal of the Canadian Association of Radiologists 30: 30—33. De Mause L (1974) The History of Childhood. New York: Psychohistory Press. De Palma L, Greco F, Specchia N, Rizzi L. (1991) Evaluation of Fracture Healing with Computerized Analysis of Radiographic Images. Radiological Medicine 82 (1-2): 44-47. Dunbar J W, HF Owen, MB Nogrady (1964) Obscure Tibial Fractures of infants — The toddler’s fiacture. Journal of the Canadian Association of Radiologists. 15:136-144. Fitzgerald ER (1977) Postmortem Transition in the Dynamic Mechanical Properties of Bone. Medical Physics 4 (1): 49-53. Frost (1989) The Biology of Fracture Healing: An Overview for Clinicians. Part 1. Clinical Orthopaedics and Related Research 248: 283-293. 99 Glencross B and P Stuart-Macadam (2000) Childhood Trauma in the Archaeological Record. International Journal of Osteoarchaeology 10:198-209. Grigoryan M, Lynch JA, Fierlinger AL, Guermazi A, Fan Bo, MacLean DB, MacLean A, and Genant HK (2003). Quantitative and Qualitative Assessment of Closed Fracture Healing Using Computed Tomography and Conventional Radiography. Academic Radiology 10(11): 1267-1273. Gwinn JL, Levin W, and Petersen HG (1961) Roentgenographic manifestations of unsuspected trauma in infancy. Journal of the American Medical Association 1761926- 929. Heinrich SD and JF Mooney III (2006) Fractures of the Shafts of the Tibia and Fibula. In Rockwood and Wilkins’ Fractures in Children 6th ed., Beaty JH and JR Kasser (eds.) Philadelphia, PA: Lippincott Williams & Wilkins. Helms CA and NM Major (2002) The Knee and Shafts of the Tibia and Fibula. In Radiology of Skeletal Trauma. Rogers LF (ed.). Vol. 2, 3rd ed. New York: Churchill Livingstone. Hendrix RW (2002) Fracture Healing. In Radiology of Skeletal Trauma. Rogers LF (ed.). Vol. 1, 3rd ed. New York: Churchill Livingstone. Hertel R and DA Rothenfluh (2006) Fractures of the Shafts of the radius and ulna. In Bucholz RW, JD Heckman, and CM Court-Brown (eds.) Rockwood & Green’s Fractures in Adults. Philadelphia, PA: Lippincott Williams & Williams. Heybeli N, Yesilda A, Oyar O, Gulsoy UK, Tekinsoy MA, and Mumcu EF (2002). Diagonistic Ultrasound Treatment Increase the Bone Fracture Healing Rate in an Internally Fixed Rat Femoral Osteotomy Model. Journal of Ultrasound in Medicine 21: 1357-1363. Hobbs CJ (1 989) Fractures. British Medical Journal 298: 101 5-1 01 8. Hufnagl (2005) An Investigation of Time Since Injury: A Radiographic Study of Fracture Healing. MA Thesis. Louisiana State University. Islam 0, D Soboleski, S Symons, LK Davidson, MA Ashworth, and P Babyn (2000) Development and Duration of Radiographic Signs of Bone Healing in Children. American Journal of Roentgenology 175: 75-78. Jones E (2003) in Green NE and Swiontkowski MF (eds.) Fractures in Children. 3rd ed. Philadelphia: WB Saunders Company. 100 Jones E (1994) In Green NE and Swiontkowski MF (eds.) Fractures in Children. Philadelphia: WB Saunders Company. Pp.1-14. Kempe RS, Silverman FN, Steele BF, Droegemueller W, and Silver HK (1962) The Battered Child Syndrome. American Journal of Medical Science 181 ( 1): 17-24. Keogh C, D Bergin, and S Eustace (2002) The Wrist. In Radiology of Skeletal Trauma. Rogers LF (ed.). Vol. 2, 3rd ed. New York: Churchill Livingstone. Kerley ER (1976) Forensic Anthropology and Crimes Involving Children. Journal of Forensic Sciences 21 (2): 333-339. Kerley ER (1978) The Identification of Battered-Infant Skeletons. Journal of Forensic Sciences 23 (1): 163-168. King J, D Diefendorf, J Apthorp, VF Negrete and M Carlson (1988) Analysis of 429 fractures in 189 battered children. Journal of Pediatric Orthopaedics 8:585-5 89. Kleinman PL, PK Kleinman, and JA Savageau (2004) Suspected infant abuse: Radiographic Skeletal survey practices in pediatric health care facilities. Radiology 233: 477-485. Kleinman PL, BDBlackbourne, SC Marks, A Karellas, and PL Belanger (1989) Radiologic Contributions to the Investigation and Prosecution of Cases of Fatal Infant Abuse. The New England Journal of Medicine 320 (8): 507-511. Kleinman PK (1987a) Introduction. in Kleinman PK (ed.) (1987) Diagnostic Imaging of Child Abuse. Baltimore: Williams and Wilkins. Kleinman PK (1987b) Skeletal TraumazGeneral Considerations in Kleinman PK (ed.) (1987) Diagnostic Imaging of Child Abuse. Baltimore: Williams and Wilkins. Kline A, Balian G Harwitz S (2005). BMP-14 Deficiency Inhibits Long Bone Fracture Healing: A Biochemical, Histologic, and Radiographic Assessment. Journal of Orthopaedic Trauma 19 (9): 629-634. Langley-Hobbs S (2003). Biology and Radiological Assessment of Fracture Healing. In Practice 25: 26-35. Lewis ME (2007) The Bioarchaeology of Children: Perspectives fiom Biological and Forensic Anthropology. Cambridge, UK: Cambridge University Press. Loder RT and C Bookout (1991) Fracture Patterns in Battered Children. Jouranl of Orthopaedic Trauma. 5(4):428-433. 101 Lovejoy CO and KG Heiple (1981) “The analysis of fractures in skeletal populations with an exmaple fi'om the Libben Site, Ottowa County, Ohio.” American Journal of Physical Anthropology 55:529-541. Maples WR (1986) Trauma Analysis by the Forensic Anthropologist. In Forensic Osteology: Advances in the Identification of Human Remains, Reiches KJ (ed.) Springfield: Charles C Thomas. McGraw EP, JE Pless, DJ Pennington, and SJ White (2001) Postmortem radiography after unexpected death in neonates, infants, and children: Should imaging be routine? America] Journal of Roetgenology 1 78: 1 5 1 7-1 521 . Mehlman CT and EJ Wall (2006) Injuries to the Shafts of the Radius and Ulna. In Rockwood and Wilkins’ Fractures in Children 6th ed., Beaty JH and JR Kasser (eds.) Philadelphia, PA: Lippincott Williams & Wilkins. Mellick LB, KB Reesor, D Demers, KA Reinker (1988). Tibial fiactures of young children. Pediatric Emergency Care 4(2): 97-101. Merten DF, MA Radkowski, and JC Leonidas (1983) The abused child: A radiological reappraisal. Radiology 146: 377-381. O’Connor JF and J C Cohen (1987) Dating Fractures. in Kleinman PK (ed.) Diagnostic Imaging of Child Abuse. Baltimore: Williams and Wilkins. Ogden J A (2000) Skeletal Injury in the Child. 31rd ed. New York: Springer-Verlag, Inc. Ogden JA (1984) The Uniqueness of Growing Bone. In Fractures in Children. Rockwood, CA Jr., KE King (eds.) Vol. 3, J .B. Philadelphia: Lippincott Co. Ogden JA (1982) Anatomy and physiology of skeletal development. In: Ogden JA (ed.) Skeletal Injury in the Child. Philadelphia: Lea & Febiger. Ogden JA (1963) Injury to growth mechanisms of the immature skeleton. Skeletal Radiology 6:23 7-253. Ortner DJ (2003) Trauma. In Identification of Pathological Conditions in Human Skeletal Remains. 2nd ed. Ortner DJ (ed.). San Diego: Academic Press. Paton DF (1992) Fractures and Orthopaedics. Edinburgh: Churchill Livingstone. Perry MA (2005) “Redefining Childhood through Bioarchaeology: Toward an Archaeological and Biological Understanding of Children in Antiquity.” Archaeological Papers of the American Anthropological Association 15(1): 89-1 1 1. 102 Prosser I, S Maguire, SK Harrison, M Mann, JR Sibert, AM Kemp, and Welsh Child Protection Systematic Review Group (2005) How old is this fracture? Radiologic dating of fractures in children: A systematic review. American Journal of Roetgenology 184: 1282-1286. Rang M (1983) Injuries of the epiphysis, growth plate and perichondrial ring. In Rang M (ed.) Children 's Fractures. Philadelphia: J .B. Lippincott. Risselada M, Kramer M, de Rooster H, Taeymans O, Verleyen P, and van Bree H (2005). Ultrasonographic and Radiographic Assessment of Uncomplicated Secondary Fracture Healing of Long Bones in Dogs and Cats. Veterinary Surgery 34 (2): 99-107. Salkind NJ (ed.) (2007). Encyclopedia of Measurement and Statistics. Vol. 1. Thousand Oaks, CA: Sage Reference, p32-35. Sauer NJ (1998) The Timing of Injuries and Manner of Death: Distinguishing Among Antemortem, Perimortem, and Postmortem Trauma. In Forensic Osteology: Advances in the Identification of Human Remains. Reiches KJ (ed.) 2"d ed., Springfield: Charles C Thomas. Sirkin RM (2006) Statistics for the Social Sciences. 3rd ed. Thousand Oaks, CA: Sage Publications, Inc. Skak SV and TT Jensen (1988) Femoral Shaft Fractures in 265 Children: Log-normal correlation with age of speed of healing. Acta Orthpedica Scandinavia 59(6): 704-707. Sledzik PS and Kelley MA. Initial Osseus Remodeling Following Trauma. Manuscript. Tiedeman JJ, Lippiello L, Connolly JF, and Strates BS (1990). Quantitative Roentgenographic Denitometry for Assesssing Fracture Healing. Clinical Orthopaedics and Related Research 253: 279-286. Toal RL and Mitchell SK (2002) Fracture Healing and Complications. In Textbook of Vetrinary Diagnostic Radiology. Thrall DE (ed.) 4th ed., Philedelphia: WB Saunders Co. Waldron T (2000) “Hidden or overlooked? Where are the disadvantaged in the skeletal record?” In J Hurbert (ed.) Madness, Disability and Social Exclusion. London: Routledge. Walker PL (2001a) “A Bioarchaeolgical Perspective on the History of Violence.” Annual Reviews of Anthropology 30:573-596. Walker PL (2001b) “Is the Battered-Child Syndrome a Modern Phenomenon?” In press: Proceedings of the 10‘h European Meeting of the Paleopathology Association. 103 Walker PL, Cook DC, and Lambert PM (1997) Skeletal Evidence for Child Abuse: A Physical Anthropological Perspective. Journal of Forensic Sciences 42 (2): 196-207. Waters PM and AD Mih (2006) Fractures of the Distal Radius and Ulna. In Rockwood and Wilkins’ Fractures in Children 6“1 ed., Beaty JH and JR Kasser (eds.) Philadelphia, PA: Lippincott Williams & Wilkins. Yeo LI and MH Reed (1994) Staging of Healing of Femoral Fractures in Children. Journal of the Canadian Association of Radiologists 45(1): 16-19. 104 MICHIGAN STATE UNIVERSITY LIBRARIES Ill IIIIII III 3 1293 3062 5804