4 biomechanical stages of bone repair

8/3/2019 4 biomechanical stages of bone repair

1/5

T he F our B iom echan ica l S tag es o f F ra ctu re R epa ir* tBY AUG USTUS A . W H ITE III , M .D ., DR . M ED . SC 4 , M ANOHAR M . PA NJAB I , T EK . L IC ., DR . TECH 4,

A ND W AYN E 0. SOU THW ICK , M .D 4 , N EW HAVEN , CO NN EC T IC UT

F rom the Eng in ee rin g L abo ra to ry fo r M uscu lo ske le ta l D is ea ses .Sect ion of O rtho pa ed it S u rg e ry . Ya le U n ive rs ity S ch oo l o f M ed ic in e , Ne w Hav en

18 8 TH E JOURNAL OF BONE AND JO IN T SURGERY

ABSTRACT : B ased on ana lys is o f the torque-anglecurv es and roen tgenograph ic find ing s in fifty -th reehea ling tib ia l fra ctu res in rabb its tested in to rsion tofa ilu re , fou r b iom echan ica l s tages o f fractu re h ealin gwere defin ed , as fo llow s: S tage I - fa ilu re th roughor ig ina l frac ture site, w ith low stiffn es s; S tag e II -fa ilu re th roug h o rig ina l frac tu re s ite , w ith h igh stiff-ness; S ta ge Ill - fa ilu re partia lly th rough or ig ina lfrac tu re site and partia lly th rough in ta ct bone , w ithhigh stiffn ess; and S tage IV - fa ilu re en tire ly th roughin tac t bone , w ith h igh stiffn ess . T hese sta ges cor-re la ted w ith th e progressive in creases in th e averagetorque and energy ab so rp tion to fa ilu re a s hea ling pro-gres sed an d a lso w ith the ave rage tim es sin ce the o rig i-na l exper im en ta l frac tu re .

It is hoped tha t th is sy stem of stag ing w ill p rov id ebo th a standard by w h ich im portan t var iab les re la tedto u ltim ate strength o f h ea ling frac tu res can be co rre -la ted and an ob jec tiv e w ay to pred ic t d ela yed un ion sand non -un ion s and to determ ine th e leve l o f ac tiv itythat is sa fe for patien ts w ith a hea ling frac tu re .

Ex isting c la ssif ica tion s o f th e stages in frac tu re hea lingare based on b ioch em ica l o bse rva tions, h is to log ica l ap -pea rances, roen tgen ograph ic c r iter ia , c lin ica l jud gm en t,o r som e com b ina tion o f these . W e are n o t aw are o f an yc lassifica tion in w hich s tages of f ractu re repa ir a re basedon ob jec tive m easu rem en ts o f the m ech an ica l p rope rties o fthe h ea ling bone te sted to fa ilu re. B y ana lysis o f th eto rque -an g le cu rv es and roen tgen ogram s m ad e a fte r fa il-u re a t hea ling frac tu re site s in rabb its , w e iden tif ied fo u rclea rly de linea ted stag es in a stu dy o rig in a lly desig ned toin vestiga te th e effec ts o f cyc lic load in g o n the ra te o f frac -tu re healin g . The h is to log ica l f ind ings in th e s tu dy an dthe effec ts o f the cyc lic lo ad ing 12 are reported els ew here.

Th e pu rpo se o f th is p resen ta tio n is to desc ribe thefo u r stages o f frac tu re repa ir and to p re sen t th e b iom echan-ica l ev idence and ratio na le o n w hich they a re based .

Des ig nExper im en ta l M ethod s

In th ir ty - th ree adu lt fem a le N ew Z ea land rabb its* K appa D e lta Awa rd p ape r, rea d in par t a t th e C om b ined M ee ting

o f the O rth op ae d ic R e se arch S oc ie ty an d The Am e ric an A cadem y o f O r-t hopa ed i c S urg eo ns, N ew O r lea ns , L ou is ia na , J an ua ry 3 0 , 197 6 .

t Th is work w as supported by U .S . P ublic Hea lth G ran t R O lAM I6O 3I a nd by The C rip p le d C h ild re n s A id S oc ie ty . N ew H aven ,Connec t i cut .: Y ale University Schoo l o f M e dic in e, 333 C eda r S tree t, N ew H a-y en , C on ne ctic ut 06510 .

w eigh in g b etw een fo ur and 4 .5 k ilo g ram s, u sing a stan -dard ized surg ica l p roced ure an o steo tom y w as done a tth e m id -sha ft o f each tib ia b elow the p o in t w he re the tib iais jo ined by the fibu la . P a ralle l K irschn e r w ire s w erep laced tw o above and tw o be low each osteo tom y site , andth e ex pe rim en tal fractu re w as red uced an d h eld b y spe -cia lly con stru cted clam p s b y w h ich the m echan ica l env i-ronm en t w as qu an titativ ely co n tro lled an d m onito red . Acons tan t com p ress io n of tw en ty n ew tons ( tw o k ilog ram sfo rce ) w as app lied to bo th tib iae , w h ile on th e rig h t o r le f ttib ia , alte rn a ting th e side in sequen tia l an im a ls , asupe rim po sed cy clic load o f tw en ty new to ns (tw ok ilog ram s fo rce ) w as a lso ap p lied . T he schedu le o f cy clicload ing w as fif ty -five co un ts pe r m inu te fo r tw o hoursin th e m orn ing and tw o hours in the a fterno on , seven daysa w eek .

A t som e tim e du rin g the th ird , fou rth , f if th , s ix th ,s ev en th , an d e igh th w eek s a fte r osteo tom y , from tw o tos ix teen an im a ls w ere k illed an d the ir h ind lim bs w ere am -p u ta ted , lab e led , and fro zen a t -20 d egrees cen tig rad eu n til te sted a t a la te r d ate .

T he su rg ica l p rocedu re s w ere ca rr ied ou t un de r gen -e ra l anesthesia using su rg ical a sepsis . T h e m id -sh a ft o f thetib ia w as ex posed , an d a transve rse osteo tom y w as m adeusing an osc illa ting saw . T he bon e w as coo led w ith re frig -e ra ted R in ge rs so lu tion as the osteo tom y w as done . A fte rthe cu t w as com p leted , the expe rim en ta l fractu re w as re-duced ana tom ica lly an d th e tw en ty -new ton (tw ok ilog ram s fo rce ) com p ressio n w as app lied th roug h theclam p s a ttached to the fo u r K irschne r w ire s th at w ere in -s er ted tran sve rsely th ro ugh the b ones.

A fte r the ope ratio n , tw o ob liqu e ro en tgenog ram sw ere m ade to check th e red uc tion . E ach rabb it w as thenfu lly sup ported o n a slin g b en ea th the ch est and stom ach .Th e fo re lim bs w ere ab le to to uch a p latfo rm wh ile the h indlim bs w ere u nsu ppo rted an d accessib le fo r app ly ing thecy clic lo ad ing d ev ice to the w ire s. T ho raz ine (ch lo r-p rom azin e) w as g iven occasio na lly in the imm edia te p ost-ope rativ e p eriod fo r re stle ssn ess bu t o the rw ise the an im a lsapp ea red to be com fortab le an d a te w e ll.S pecim en P repa ra tion

P rio r to tes tin g the tib iae w ere d isa r ticu lated a t thekn ee and ank le , an d the sk in w as ca refu lly rem oved , leav -ing the m usc le in tac t be tw een the pa irs o f K irschner w iresto p reven t the bo ne spec im ens from dry ing ou t du ring thete sting procedure as w ell as to pro tec t th e h ealing fractu refrom acc id en ta l dam age du rin g d issec tion o f the so ft tis-


2/5

l.5

MAX IMUM TORQUE (1 )

EN ERG Y ABSORPT IO N (3 )

0 5 0ANGU LAR D ISPLAC EM ENT (D eg re es )

FIG . 1

THE FOUR B IOM ECHAN ICA L STAGE S OF FR AC TUR E R EPA IR 18 9

VOL . 59-A , NO . 2, M ARC H 1977

su e. T he p ortio ns o f the tib ia p rox im a l and d is tal to th eK irschne r w ire s w ere rem oved an d the tw o ends, inc lud ingthe w ire s, w e re po tted in q u ick -se ttin g p o lyeste r re sin toensu re p rec ise f it and fixa tion of each sp ecim en in theto rsion -te sting m ach ine . R oen tg en ogram s of the p repa redspec im ens w ere th en m ade in tw o p lanes at 9 0 degreesto each o th er .T orsio n T est

The bones w ere te sted in a to rsion -te sting m ach ine(A . H . B urstein , N ew Y ork , N .Y .) w h ich w as conn ectedto a reco rd in g osc illo sco pe (T ech tron ic ty pe 5 6 1 B ). U s in gth is experim en ta l setup , four m echan ica l m easu rem en ts o fth e stren g th o f each tib ia w h ile it w as sub jec ted to to r-s iona l load ing w ere de te rm in ed . T hese w ere : m ax im umto rq ue (1 ) , to rsion ang le (2 ) , ene rg y ab so rp tion (3 ) , ands tiffn ess (4 ) (F ig . 1 ). M ax im um torq ue w as the to rque atw hich the bone failed . T h e to rs io n ang le w as th e num bero f degrees o f to rsion al de fo rm atio n in the te st b one justp rio r to fa ilu re . M o st o fthe bon es be fo re th irty d ays o f hea l-ing had very low stif fness an d there fo re had angu la r de-fo rm a tion s o f a s m uch as 40 deg rees a t m ax im um torq ue .S ince an gu la r d efo rm a tions g rea te r than 8 deg rees w ou ldno t be c lin ica lly accep tab le , th e load -de fo rm atio n curvesfo r these w eak bon es w ere cons ide red o n ly u p to 8 de -g rees o f de fo rm atio n , and the m ax im um torque , ene rgyabso rp tio n , and stif fne ss w ere com puted at 8 d eg rees o fde fo rm atio n . T h is p ro cedu re , w e be liev e, pe rm itted va lidcom pariso ns o f th ese w eak bones w ith th ose tha t hadm ax im um defo rm atio ns in the v ic in ity o f 8 d eg rees. T heene rg y ab so rp tion w as used as a m easu re o f the ene rg y pu tin to the bon e un til failu re . It is rep re sen ted in F igu re 1 by

TORQUE(New ton Me te rs )

I .0

0. 5

A ty p ic a l c om pu te r-p lo tted to rqu e -an g le d is p la cem en t g ra ph show ingfo u r s tre ng th pa ram e te rs num bere d from one to fou r.

the shaded a rea un de r th e to rqu e-ang le cu rve up to th epo in t o f failu re . S tif fne ss w as de fin ed b y the to rq ue -ang lecu rve , w h ich w as n on-linea r. T he refo re , a sing le n um bercou ld n o t rep re sen t the true stif fn ess o f th e b one ; w e usedth e ra tio o f the m ax im um torq ue to the ang le at tha t po in t(F ig . 1 ) to d efine the stiffne ss o f th ese b ones.

ResultsOne o f the goa ls o f th is in vestiga tion w as to te st the

h ypo thesis tha t the ra te o f frac tu re hea ling is in f luenced bythe m ech an ical env ironm en t. T o do th is the ra te s o f in -c rea se in stren g th in the frac tu red tib iae o f each rab b itw e re de te rm in ed , on e tib ia hav in g b een sub jec ted to con-stan t com pres sion an d the o the r, to bo th co nstan t an dalte rna ting com pressio n . T he resu lts , repo rtede l s ewh ere 12 , sh ow ed tha t w hen a ll tib iae w ere com paredthe re w as n o d iffe rence in h ea ling ra tes in the tw o m echan-ica l en v ironm en ts used . The refo re , a ll o f th e h ea ling b onesw ere p u t in to o ne group w ith ou t con side ring w he the rcom press ion or com pres sion com bined w ith cy clic load -ing had been app lied . T h is com b in ed g roup w as d iv id edacco rd ing to hea lin g tim e in to six sub group s o f frac tu re sstud ied a fte r th ree, fou r, f iv e , s ix , seven , an d e igh t w eek so f h ealin g.S treng th M easurem en ts a s a Fun ctio n o f T i,n e

F if ty - th ree o f the six ty -six bo nes w ere te sted andan aly zed . T h ir teen b on es w ere lost o r fo r techn ica l reasonsco u ld no t b e an a lyzed . T he m ean va lu es p lus o r m inus on estand a rd dev ia tion of the th ree m easu rem en ts o f streng tha re lis ted in T ab le I . T he ave rag e m ax im um torq ue inn ew ton -m ete rs (on e n ew to n-m ete r = ten k ilog ram sfo rce-cen tim e ter) a s a func tio n o f h ea ling tim e in days w aspro bab ly the best in d ica to r o f streng th . U p to abou ttw en ty -th ree d ay s, the to rqu e re flec ted the so -ca lledstreng th o f the so ft tis sues co nnec ting the fragm en ts andthe su rro und ing bone . A s hea ling progre ssed , the to rqu estren g th inc rea sed and reach a va lue o f abou t 1 .5 n ew to n -m e te rs a t e ig h t w eek s. T he en e rgy abso rp tio n , th e w o rkd one on the b one to de fo rm it up to th e po in t o f failu re ,reached a v alu e o f abo u t 0 .0 75 new ton-m e te r a t e igh t w eeks.T he ave rage stif fne ss rose sha rp ly and th en seem ed toleve l o ff at som e tim e afte r e igh t w eek s. A dd itio na l d e-

TABLE ICHANGES IN STRENGTH PARAM ETERS OF

EXPER IMENTAL FRACTURES AS A FUNCT ION OF T IME

Hea l ingT ime( W eeks )

N o. ofBone s

Torque( N m)

Av . S .D .Energy( N m)

A v. S .D .

St if fness(Nm/Deg . )A v. S .D .

3 2 0. 22 0.0 9 .016 . 007 .028 .0124 14 0 .3 5 0 .3 1 .0 1 9 .0 1 0 .08 1 .10 65 4 0. 75 0.30 .040 .015 .126 .0576 4 1 .1 3 0 .5 1 .0 65 . 047 .264 .0927 16 1 .3 3 0 .52 .0 72 .0 3 2 .25 7 .1 0 08 13 1.40 0.4 8 . 071 .042 .322 .074


3/5

56R ab bit # 54

TORQuE(NT-Il)

5 10A NG UL AR D IS PL OC EM EO T (D EG RE E) F IG . 3

F IG . 2A c om p os it e to rqu e -ang le g ra ph o f s ix b ones re p res en ta tiv e o f th e en -

tire he a ling pe rio d . Th e num bers o n th e g ra ph s in d ic a te day s o f he a lin gtim e. A s hea lin g p ro g re sse s , th e re is an in crea se in t he s tr en g th of un ionsh ow n by the changes in t he to rq ue -a ng le graphs .

f tCUt5 R D IS PL AC EM EN T (D EC RE ES )

FIG. 5 FIG. 6 FIG. 7F ig . 4 : R oen tg en og ram s o f S tag e -I frac tu re he a ling b e fo re (le ft) a nd a fte r (rig h t) tes ting . R ubbery low -s ti ffne ss fa i lu re o ccu rred a t th e frac tu re s ite .F ig . 5 : R o en tg en og ra m s o f S ta ge -Il frac tu re h ea lin g be fo re (le ft) an d a fte r (rig h t) tes tin g . H ard -tissu e , h ig h -s tiffn es s fa ilu re oc cu rred a t the frac -

ture s ite.F ig . 6 : R oen tg eno gram s o f S tag e - Ill frac tu re h ea lin g b e fo re ( le f t) an d a fte r (rig h t) tes t ing . H a rd -tis sue , h igh -s ti ffn ess fa ilu re o ccu rred b o th a t th e

fra c tu re s ite an d in the in tac t bo ne .F ig . 7 : R oen tge no gram s o f S tag e -IV frac tu re h ea ling be fo re (le ft) an d a fte r (r igh t) te s ting . H ard -t iss ue , h ig h -s tiffne ss fa ilu re o ccu rre d en tire ly in

th e in tac t bon e.

19 0 A . A . WHITE III, M . M . PAN JA B I, AND W . 0 . SOU THW ICK

TH E JOURNAL O F B ONE AND JO INT SURGERY

tails o f the tem pora l ch an ges in streng th a re g iven e lse -whe r e 10C hanges in the T orque -A ng le Gr a p h s

T he chang in g pa tte rn s o f the to rqu e -ang le g raphs o fs ix rep resen ta tiv e bo nes w ith hea lin g tim es ran g ing fromtw en ty -on e to fifty -six days a re sh ow n in F ig u re 2 . F romthese graphs it is ev id en t tha t the stiffness inc reased w ithtim e in b o th the in itia l an d the fina l pa rt o f hea lin g .

T he earlie st ev idence o f re tu rn in g stren g th w as seena fte r tw en ty -one to tw en ty -fo u r day s o f h ea ling . In thebones w ith hea ling tim es of tw en ty -one to tw en ty -sixdays , the so ft tis su e had a ru bbery typ e of behav io r -th a t is , a low to rqu e and a la rg e angu lar d efo rm a tion as-soc iated w ith a low stiffness. In the la te r phase of hea ling ,a fte r fo rty -n ine to f ifty -six days, the bon es had a h a rd -tissue type of behav io r - tha t is , a h igh to rque an d sm a llangu lar de fo rm a tion assoc iated w ith a h igh stif fn es s . T he

To rqu e -ang le g ra ph s o f the t ib ia e o f on e rab b it a fte r tw en ty -s ix da yso f h ea lin g, d em onstra tin g a d ram atic d iffe ren ce in th e pa tte rns o f thetw o cu rves . The le ft bo ne is s tron ge r a nd has a h ard -tis su e typ e o f c u rv e ,whi l e the righ t bone is w eake r and has a so ft-tissue type o fcu rve . The righ tle g wa s sub jec ted to com p re ss ion an d cy c lic loa d in g a nd th e le ft . to c om -p res s io n o n ly . In the who le se ries , the re w as n o co ns is te n t d iffe ren ce a s-so c ia ted w ith the two types o f trea tm en t 12

so ft-tissue an d h ard -tissue phases w ere sharp ly dem ar-cated a t approx im ate ly tw en ty -s ix to tw en ty -sev en d ay s byan abrup t ch an ge , d ram a tically ex em plified b y theto rq ue -ang le p lo ts o f a p air o f bo nes from the s a m e rabb i t(F ig . 3 ) . T h ese tib iae a f ter tw en ty -six day s o f hea ling hadto rqu e-ang le cu rves tha t w ere m ark ed ly d iffe ren t. T herigh t tib ia (26 R ) fa iled w ith low stiffn es s (a rubb ery ,so ft-tis su e typ e of fa ilu re pa ttern ) and the le ft tib ia (26 L )fa iled w ith re la tiv e ly h ig h s tiffness (a hard -tis sue type offa ilu re pa tte rn ).

Th e F ou r B iom echan ica l S tages o f H ea lingT he d is tinc t chang e in the load -de fo rm a tio n curve a t

tw en ty -s ix to tw en ty -seven days from a rubb ery qua lity toa m uch s tiffer , ha rd -tis sue typ e o f re siliency is som e tim esev iden t c lin ica lly w hen frac tu res a re trea ted in trac tion .B o th th e phy sic ian and the p atien t m ay ob se rv e tha t the


4/5

M AX MUMTORQUE

ENERGY1. 5

UiI- I0

0. 5

0Stage

n=F IG . 8

H is to g ram show in g ave ra ge m ax im um to rq ue s fo r th e fou rbiomechani ca l s tages o f fra ctu re hea lin g . V e rtic a l line s abo ve an d be lo wth e a ve ra ge po in ts re p resen t on e s ta nda rd de v ia tio n from th e m ean .

.1 0

UiI-Ui

z0I-Uiz

.0 5

0S tage I II III IV

n (10 ) (7 ) (15 ) (21 )F IG . 9

His togram show ing a ve ra ge ene rgy abso rp tio ns fo r th e fou rbiomechanical s ta ge s o f f ra ct ur e hea lin g . V ertica l line s abo ve an d b e lowth e av erage po in ts rep resen t one stand ard d ev ia t ion from th e m ean .

I II III(JO ) (7 ) (1 5 ) (2 1 )

THE FO UR BIOM ECHAN IC AL STAGE S OF FR AC TUR E REPA IR 19 1

VOL . 59 -A , NO . 2, M ARC H 1977

frac tu re becom es s tuck du rin g a rath e r sh o rt p eriod oftim e . I t is th is change from the sp ringy , e la stic , low -stiffness res istance to the m ore rig id , h igh-s tiffness resis -tance tha t the c lin ic ian fee ls w hen the frac tu re becom esstuck .

In to rsio na l te sting on e exp ec ts the failu re to o ccu r atthe w eak es t pa rt o f the struc tu re . In the hea ling tib ia l frac -tu re s in o ur rabb its te sted w ith to rsion al load ing , fa ilu reo ccu rred in o ne o f th ree w ays , w ith the fa ilu re lines in oneo f the fo llow ing positio ns: p u rely th roug h the expe rim en-tal frac tu re (hea ling os teo tom y site) ; pa rtia lly th ro ugh theh ea ling experim en tal frac tu re an d p ar tia lly th roug h the in -ta c t bon e; o r en tire ly th roug h the in tac t bo ne , no t inv o lv -ing th e hea ling expe rim en ta l frac tu re .

B ased on these ch aracte r is tics o f hea ling b one tes tedto failu re , w e estab lished th e fo llow ing fo ur b iom echan i-ca l s tag es o f frac tu re repa ir.

S tage I: The bone fa ils th ro ugh the o rig ina l expe ri-m en ta l fractu re site w ith a low -stif fne ss , rub be ry p atte rn ,and a to rque -an g le cu rve lik e the one fo r th e tw en ty -on e-d ay cu rv e in F ig u re 2 . The fa ilu re m ode o f a bon e in th isstage o f hea ling is illu stra ted by th e roen tg enog ram s m ad eb efo re and a fte r fa ilu re sh ow n in F igu re 4 .

S tage II : T he bone fa ils th roug h the o rig ina l ex pe ri-m en ta l frac tu re site w ith a h igh -stif fn e ss , ha rd -tissue pa t-

tern lik e the tw en ty -seven-day curve in F igu re 2 , and afa ilu re m ode like the on e illu stra ted by the roen tg en o-g ram s m ade be fo re and a fte r tes tin g sh ow n in F igu re 5.

S tage 111 : T he bone fa ils pa rtia lly th ro ug h th e o rig i-n al expe rim en ta l frac tu re s ite an d pa rtially th ro ugh thep rev io usly in tac t bo ne w ith a h igh -stiffne ss , h ard -tissuep a ttern lik e th e fo rty -n in e-day to rqu e-ang le cu rv e pa tternin F igure 2 . A n ex am ple of a S tag e- Ill failu re m od e is seenin the roen tgen ogram s in F ig u re 6 w hich w ere m ad e be fo reand afte r te stin g .

S tage 1V : T he site o f failu re is no t re la ted to the o rig -ina l expe rim en ta l frac tu re and o ccurs w ith a h igh -stif fn es spa tte rn like the fifty -six -day cu rv e illu stra ted in F igu re 2 .T he fa ilu re m ode h ere resem ble s th e on e show n on theroen tgeno gram s in F igure 7 .

Havin g iden tif ied these s tag es w e reaso ned th at ifthey a re va lid and a re to be m ean in g fu l an d use fu l, th eysho u ld co rrela te w ith th e qu an tita tive m easu rem en ts o fstreng th as w e ll a s the tim e sin ce frac tu re . T he b ones w erethe re fo re g ro uped in to the fou r b iom ech an ica l s tages onthe basis o f the te st da ta , and the av erage m ax im um to rq ueand ave rag e en ergy ab so rp tion to failu re fo r each groupw ere d ete rm ined (F igs. 8 and 9). A lth ou gh th ere w as con -s ide rab le v aria tio n , a d istin ct trend w as ev id en t in th ep rogre ssive inc rea se in s treng th from S tag e I to S tage IV .W hen th e av erage tim es a fte r fractu re fo r the bon es in eacho f the fo u r stages w ere com pared , th e sam e p ro gre ss io nw as ev iden t (F ig . 10 ) . A s dem on strated by the h istog ram s(F igs. 8 , 9 , and 1 0), th e fou r stages co rre lated c lose ly w ithstreng th and hea ling tim e , and th e sta tis tic al co rre la tion so f th e d iffe ren ces sh ow n in th ese h istog ram s as de te rm inedby t te st w ere sign if ican t (T ab le II) , excep t those fo ren ergy abso rp tio n in th e la ter stages o f h ea lin g .


5/5

S IGN IF KANCE OF D IF FERENC ES B ETW EEN TH E M EAN MAX IMUM TORQUES ,ENERGY ABSOR PT IONS . AND H EALIN G T IM ES OF THE FOUR STAGES 60 FRACTURE

I-I l 1Il-I ll :1:

Ill-IV 1: *t 40

>-0

20

0-Stage I

n = (10)H ifi Iv(7 ) (15) (21)

Histogram sh ow ing ave ra ge hea lin g t im e s a nd s tan da rd de v ia tion s fo rth e fou r b iom echan ica l s tag es o f frac tu re h ea lin g .

m ore roen tgeno grap h ic in fo rm a tion relev an t to the fo u rs tages of hea ling becom es ava ilab le , it m ay b e po ss ib le toreco gn ize an d iden tify the stages o f fractu re h ealin g a t an yg iv en tim e in the c lin ica l s itua tion .

References

TH E JO UR NAL OF B ONE AND JO INT SUR GER Y

19 2 A . A . W H ITE III , M . M . PAN JA BI , A ND W . 0 . SOU THW ICKTABLE II

S tag es M axim um EnergyCompa r e d T orque Ab sorp tion Hea lin g T im e

I-Ill * *ll- lV t *

* p < 0 .0 1 ( si gn if ic an t) .. p < 0 .0 5 ( si gn if ic a nt ).1: p > 0 .0 5 (n ot s ig nif ica nt) .

DiscussionTh e precis e, o b jectiv ely d ete rm ined d em arcatio n be -

tw een th e s tages and the corre lation s of th e streng th d e-te rm ina tions and hea ling tim e m ake us o p tim istic abou t thev alid ity an d po ten tia l u se fu lness o f the prop osed classifica-tio n . T he need fo r non-d estruc tive tests o f bone s treng thhas a roused cons id erab le in te rest 13 , 59 , h 1 , and the fou rstages o f hea ling defined b y our b iom echan ica l te stsshou ld be of v alu e in the deve lopm en t o f such clin ica ltes ts. T he end of S tage I is read ily recog n izab le c lin ica llyby physica l exam ina tion or by m ore o b jec tive tes ts6 -9 . If

I . ABENDSCHE IN . WALTER , and HYATT , G . W .: U ltrason ics and S e le c ted Ph ys ica l P ro pe rtie s o f Bo ne . C lin . O rthop . . 69: 2 94 -30 1 , 19 70 .2. BRASH , J . I. . an d SKORECK I , J .: Termina t ion o fth e M odu lu s o fE la s tic ity o f B on e b y a V ib ra tio n M e th od . M ed . B io l. E n g . , 8 : 38 9 -3 93 , 19 70 .3. CAMPBEL L , J. N ., a n d JUR IST . J . M .: M echan ic a l Im ped an ce o f the F em u r: A Pre l im ina r y Repo rt. J . B iom ech ., 4 : 3 19 -3 22 , 1 9 71 .4 . CR ELIN , E . S .: WHIT E . A . A .; PANJAB I , M . M .; a nd SOUTHWICK, W . 0 .: C orre la tio ns o f M icros co p ic A na tom y w ith Physic a l P rop e rties o f

H ea ling F ractu res. (To b e p u bl is he d .)5. DOHERTY , W . P .: B 0v ILL , E . G .; an d WILSON , E . L .: E valuat ion of the Us e o f Resonan t F requencies to Charac te rize Phys ic a l P rop e rties o f

H um an L ong Bones. J . B iom ech ., 7 : 55 9 -5 61 , 19 74 .6. J E RNUE RGE R . ACKE : M easu rem en t o f Stabil ity of T ib ia l F ra ctu res . A M echan ica l M eth od . A cta Or thop . Scand inas ca . Su pp lem en tum 135 ,

1970 .7. JUR IST , J. M .: In V iva Det erm ina t i on of the E las tic R e sp on se o f B one . I. M e tho d o f U lna r R esona n t F requency D cte rm in a tion . P hys. Med .Biol.. 15 : 417-426 . 1 97 0 .

5. L EW IS , J . L .: GOLDSM ITH . W .: an d WONG , A .: Im pac t R e sp on se o f L on g B ones as a D iag no stic To o l b r F rac tu re Hea ling . P roc . 26 th A nnu alC on fe re nce on E ng ine e r ing in M ed ic ine a nd B io lo gy . p . 45 , 1973 .

9. MATTHEWS . L . S .; KAU FER , HER BERT ; an d SONSTEGARD , D . A .: M anua l S ens in g o f F ra c tu re S tab ili ty : A B iom echan ic a l S tud y . A c ta O rth op .Scand inav ic a , 45 : 373-381 , 1974.

10 . PANJAB I . M . M ., a nd WHIT E , A . A .: Tem pora l C h anges in th e P hys ica l P rop e rt ies o f H ea lin g Bone F ra c tu re s . (T o he pub lishe d .)I I. THOMPSON , G . T .: In V ivo D e te rm ina tion o f B one P rop er ties from M echan ica l Im pedan ce M easurem en ts . A bs tra c t from A ero sp ace M ed ic a l

A sso c ia tio n Annua l S c ien ce M ee tin g , La s V egas , N e vad a , M ay 1973 .12 . WHITE . A . A .; PANJAB1 , M . M .; an d SOUTHWICK , W . 0 .: E ffec ts o fC om p res s io n an d C yc lica l L oa d in g on F rac tu re H ea lin g . A Q uan t ita t iveB iom echan ica l S tud y . (To b e pub lis hed .)

4 biomechanical stages of bone repair

Documents