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34 W . C . HEAD

THE JOURNA L O F BONE AND JO INT SURGERY

8. J O LLEY . M . N .: SALVAT I , E . A .: an d BROW N . G . C .: E ar ly R e su lts a nd C om plic atio ns of Su rfac e R epla cem en t o f the H ip . J . B on e and Jo in t

Su r g . . 64 .A : 366- 377, March 1 982.

9. MA. S . M . : K A ISO , J . M . : an d AM 5TUT z. H . C . : F r ic tiona l To rqu e in S urface and Conventio na l H ip R epla cem en t. J. B one and Jo in t Su rg . .

65-A : 366- 370, March 1983.

10 . MALLORY . T . H . , an d D AN i. JOHN : Con se rvat ive To tal H ip R epla cem en t. A Com parison o f W agne r R esu rfa cing A rthro p la sty and T otal A r ticu lar

R eplacem ent A r thro p lasty . O rth oped ic s. 5: 10 1 2- 1 (1 1 5 . 1982 .

II. SE W HOY . A . L .: HEDLE A . K .: C LARKE . I. C .: GRUEN . T . A . W .: AMSTUTZ , H . C .: CO STER . I. : an d MOR ELAND . J . R .: T he A cetabu lar

C em en t-B one In te rfac e in Exper im ental A rth rop last ies in D og s. C lin . O rth op .. 155 : 231-2 43 . 1 981 .

12 . T0wNLE \ - . C . 0.: H em i and To tal A rticu lar R ep lacem ent A rthrop lasty o f th e H ip w ith th e F ixed Fem o ral C up . O rth op . C lin . N orth Am e rica , 13 :

869-894 . 19 82 .

13 . TRENTAN I , C .

,an d VACCAR INO . F .: Ita lia n Expe rien ce. R e sur fac ing A rth rop las ty U sing th e P altr in ieri-T ren tan i R esurfacin g A rthro p la sty , 8 Y ear

A sses sm ent. O rth op . T rans., 5: 374 . 198 1 .

(up righ t I M4 h flu Journa l o / B one ii,id J oi nt .5 ur , i . i ncor pora t t - d

Th e R o le o f C om pu ter ized T om ograph ic S cann in g

in th e E va lu a tion o f M a jor P e lv ic F rac tu res

BY KEVIN G ILL . M .D .t , A ND ROBERT W . BUCHOLZ , M D .I’, DALLA S, TEXAS

From the D iv is ion o f O r tho paed ic Surgery . U n is-ers irs- o f Te xa s H ea l th S cie nc e C en ter a t D a llas . D a lla s

ABSTRACT : Tw en ty -five patien ts w ith doub le v er -

tica l frac tu res of th e pe lv ic r ing had eva lua tion s by bo th

p la in rad io graphy and com pu ted -tom ography scann ing

of th e pe lv is . In e igh t o f th e tw en ty -five patien ts, th e

in terp re ta tion tha t w a s m ade from the p la in rad io-

g raph s, ba sed on th e cla ssif ica tion o f P ennal et a l.,

chang ed w hen add itiona l anatom ica l in form ation w as

prov id ed by th e com pu ted-tom ography scan . W e rec-

omm end that com pu ted tom ography be u sed for : (1 )

doub le vertica l fra ctu re-d isloca tion s of th e pe lv ic ring in

w h ich p la in rad io graph s are inadequate to judg e pe lv ic

stab ility , (2 ) fra c tu res o f the pelv ic r ing w ith ex ten sion

in to th e ace tabu lum , and (3) m a jo r in ju r ie s to th e

hem ipe lv is that are to b e trea ted by open reduction and

interna l fix ation . H ow ever , due to th e in creased co st and

rad iation exposure , rou tin e com pu ted -tom ography scan -

flin g is not ju stif ied fo r a ll in ju r ie s to th e pe lv ic r ing .

V ertica l fractu re s tha t are on the sam e s ide o f the p e lv ic

ring . an d a re bo th an ter io r and poste rio r to the ace tabu lum

(M alga ig ne pa tte rn ), m ay re su lt in an un stab le hem ip elv is .

S u ch in ju r ies a re a lead in g cause o f m o rb id ity and m orta lity

in the m ultip ly in ju red pa tien t. A ltho ugh im pro ved the ra -

p eu tic techn iq ues d irec ted a t in trap elv ic hem orrh age andasso cia ted pe lv ic v isce ra l in ju r ie s hav e d im in ish ed th e p re-

v io usly h ig h fa tality rate s , little p rog re ss h as been m ade in

red uc ing the ch ron ic d is ab ility tha t o ften fo llow s these h igh -

ene rgy in ju r ies . The in c idence of sym p tom a tic lim b-leng th

d isc repancy , p elv ic o b liqu ity , sa cro -ilia c a rth r itis . l ow -b ack

pa in , and pe rm an en t de fic its o f the Ium bo sacra l p lexu s re -

m a ins h ig h35 . D is sa tisfac tion w ith the lon g-te rm resu lts o f

5 R ead at the A nnua l M eeting o f The Am er ican A cad em y of Ortho-

pa ed ic S urg eon s. A nah eim . C a lifo rn ia . M arch I I . 1983 .

t D ivis ion of O rtho paed ic Su rge ry . U niv ers ity ot T ex as H ealth S ci-

ence C en ter, 5 323 H arry H ine s B ouleva rd , D a llas . T exas 75235.

conv en tion al treatm en ts h as stim u la ted a n ew in te re st in

do ub le ve rtica l frac tu re -d isloca tions o f th e hem ipe lv is .

In o rd er to m ake co rrec t the rapeu tic d ec isio ns it is

e ssen tial tha t the p elv ic in ju ry b e p ro pe rly cla ssif ied , w h ich

in tu rn dep en ds on th e p recis e d ete rm ina tion of its pa tho -

log ica l ana tom y . A ccurate re sto ra tio n of th e ana tom y of the

pe lv ic ring is the su re st w ay to m in im ize fu tu re m o rb id ity .

M o st c las sifica tion sy stem s re ly on a clin ica l jud gm en t o f

the p rob ab le m ech an ism of in ju ry , and a re based on th e

in te rp re ta tio n of standa rd an te ro poste r io r , in le t, and tilt ra -

d io g raph s o f the pe lv is6 . T he q ua lity o f these ro u tine

rad io g rap hs va ries w ith the po sition of the in ju red pa tien t,

ov erly ing so ft-tissue an d gas shadow s, and rad iog raph ic

re so lu tion . A p rec ise de te rm ina tion of the ex ten t o f th e

osseou s and ligam en tou s in ju ry to th e pe lv is , w h ich is e s-

sen tia l fo r co rrec t the rapeu tic dec ision s, is th ere fo re o ften

im possib le. Th e purpo se o f th is stu dy w as to ascerta in if

com pu te r-a ssis ted tom ograp h ic scans s ign if ican tly aid in the

d elin ea tion of the pa tho log ica l ana tom y o f do ub le ve rtica l

frac tu re s o f th e p elv ic r ing .

M ater ia ls and M ethods

Tw en ty -f ive pa tien ts w ith d oub le ve rtica l frac tu re o f

the pe lv ic r ing w ere exam ined w ith bo th ro u tine an te ro -po ster io r rad iog rap hs and p e lv ic com pu ted -tom ography

scan s. A ll pa tien ts h ad su sta ined at lea st o ne frac tu re an te rio r

and one p oste rio r to eith er ace tabu lum . Th e ag es o f the

pa tien ts ran ged from e leven to s ix ty - th ree years (m ed ian ,

th ir ty years) . T h ere w ere e igh t fem ale an d sev en teen m ale

pa tien ts . A ll in ju r ie s w ere cau sed by a h igh -ene rg y im pact

su ch as a m oto r-v eh icle acc iden t o r a fa ll from a h eig h t.

E ach in ju ry w as c la ssif ied by the sch em a of P en na l et

al . , us ing th e in fo rm atio n ob ta ined from pla in an te ropo s-

teno r rad iog raphs. In let and tilt rad iog raphs o f th e pe lv is

w ere no t m ad e rou tin ely , in o rde r to m in im ize the to ta l

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!: i FIG. 1-A

In th is eig h te en-yea r-o ld p atien t th e an tero po ste rio r rad iog rap h is sugg est ive of a sta b le la tera l com p ress ion in jury o f th e p elv is.

F IG . I- B

T he com puted- tom og rap hy scan , how ever . dem onstra te s an u nsta b le f ractu re w ith com m inu tion of the sacro-il iac jo in t a nd p os terio r d isp lacem ent

of th e hem ip elv is.

COM PUTERIZED TOMOGRAPH IC SCANNING IN THE EVALUATION OF MA JOR PELVIC FRACTURES 35

TABLE I

D IAGNOSES MADE FR OM Pt. . ; iN R AD IOGR A PHS C oSIPAR I:D V iTH TH OSE M ADF. FR OSt C o slP tTF :n-T osio uR xPH \ S- sNs

I ni ti al C l as si fi ca ti on .

B ased on A ntero pos terto r F ttia l ( ‘la ssit tca tion . B a sed on

R adiograph s C om pu ted -To tito graph v Scans

A nte rop osterio r con ipre ssion in ju ry A nte rop osterio r com p res sio n in jury

L ateral c om pre ssion in jury I.a tera l com p res sio n in jury

3

‘. c::% .4 7

2 I 7

7

I 5

2 5 25

V e rtic al she ar in ju ry V ert ical she ar in ju ry

T ota l T otal

* In tw o of th ree app aren t an te rop os terio r com press ion in ju rie s, fou r o f sev en ap paren t la teral com p res sio n les ion s, an d tw o of f ifte en ap paren t

ver tica l-shea r in ju ries, a change o f d iag nos is w as m ade .

1 B ased on the class ific atio n of Penna l et a l.

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4

FIG. 2- A

T his preope rat ive p la in rad io graph o f a sev en teen -ye ar-o ld patien t show s comm inu tion of th e sac ral pa rs la te ral is a nd d ias tasis of the pu bic sym phy sis

w ith cepha lad d isp la cem en t o f the left hem ipe lv is.

Th e po sto perativ e rad iog rap h in the sam e patien t sh ow s screw fix ation o f th e le ft s acro-il iac jo in t and plate fix ation o f th e pu bis .

36 KEV IN G ILL AND R . W . BU CHOLZ

THE JOURNAL OF BON E AND JO INT SURGERY

rad ia tion exp osu re o f th e p atien t. T h e th ree m ajo r catego rie s

in th e cla ssif icatio n o f P enn al e t a l . a re : ( 1 ) a nte ro po ste rio r

com p ressio n in ju ry , (2 ) la te ra l com pression in ju ry (stab le

o r u nstab le ), an d (3 ) ve rtica l shea r in ju ry .

C om puted -tom ograph y scans o f th e pe lv is w ere a lso

m ade fo r a ll tw en ty -f ive p atien ts w ith in one w eek of the

tim e o f in ju ry . Th e ana tom ica l d a ta ob tain ed from the scans

w ere th en used to rec la ssify each in ju ry .

Th e G en era l E lec tric 8 800 h igh -re so lu tio n w ho le -b ody

scann e r w as used fo r all pa tien ts . T h e pa tien t w as pos itioned

in the d oughnu t-sh ap ed gan try o f th e scan ne r, w h ich cou ld

be v a ried in d iam e te r from tw en ty to fo rty -fiv e cen tim e te rs .

1 !

4

T he gan try a lso cou ld be tilted to as m uch as 20 degrees

o ff the v ertical, thu s a lter ing the p lane o f tom og raph y to

im p rov e v isua liza tion of any fractu re fragm en ts . F iv e -m il-

lim e te r con tiguo us c ross-sectio na l im ag es w ere m ade eve ry

tw en ty -tw o seco nds, w ith a rad ia tion do se o f ap prox im ate ly

on e rad pe r ax ia l cu t. A n av erage of eig h t to ten ax ia l cu ts

w as n ecessa ry to eva lua te th e po ste rio r elem en ts o f the pe l-

v ic r ing . A n en tire pe lv ic s tudy w as com p leted in le ss th an

ten m in u te s. The an ter io r p art o f th e pe lv ic r ing w as no t

rou tine ly scan ned , thu s m in im iz ing the to tal rad ia tion do se

to the pa tien t.

Tw elv e o f the pa tien ts un de rw en t su rg ica l p roced ures

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Th e postope rat ive com puted- to ti iog rap hy scan rev eals tha t th e screw thre ads d id n ot g ain ad equ ate p urcha se on the in ta ct sac rum . T his u ns atis fac to ry

po sition of the screw s de lay ed m obiliza tion of th e pat ien t.

C OM PU TER IZED TOM OGRAPH IC SCANN ING IN THE EVA LUAT ION O F M A JO R PELV IC FRACTURES 37

VO l. 66 -. . NC ) I . JAN UARY 1954

an d h ad fo llow -up com puted -tom ograp hy scans to ev alu ate

th e resu lt.

Results

In eig h t p atien ts th e in itia l c la ssif ica tion o f the pe lv ic

in ju ry , m ade from p la in rad iog raphs , w as chang ed b ecause

o f the ad d ition a l ana tom ica l in fo rm a tion prov id ed by the

com puted -tom ography scan . Four o f these pa tien ts h ad had

th e com ple te p la in rad iog raph ic s tudy , in c lud in g an te ro -

po ste rio r , tilt, an d in le t rad io g rap hs. T ab le I lis ts th e changes

in c la ssif ica tion acco rd ing to spec ific m ech an ism o f in ju ry .

F o ur in ju rie s th at o rig ina lly had b een c la ssif ied as stab le

w ere rec las sified as un stab le ve rtica l-shear in ju r ies (F ig s.

1 -A and 1-B ). In tw o o f th ese pa tien ts seve re comm inu tio n

of th e sac ro -ilia c jo in t w as sh ow n on the com puted -tom og-

raphy scan , and tw o dem ons tra ted p rev ious ly u nsu spec ted

poste r io r d isp lacem en t o f the ilium at th e sac ro -ilia c jo in t.

In s ix pa tien ts occu lt in ju rie s to th e con tra la tera l s ac ro -ilia c

jo in t w ere revea led b y the scan .

U n expected ex tensio n of the hem ipe lv ic frac tu re in to

th e ace tabu lum w as m ade v isib le by the com puted -tom og-

rap hy scan in th ree pa tien ts . S im ila r ly , an un satis fac to ry

p osition of th e sc rew s, w h ich w as im possib le to v isua lize

on the p la in rad iog raph s, w as show n by the pos to pe ra tive

scans in th ree pa tien ts (F ig s. 2 -A , 2 -B , an d 2-C ).

Th e scanne r can produ ce sag ittal reconstruc tive im ages

by u tiliz ing the in fo rm atio n prov id ed b y th e ax ial im ages.

I t c rea te s an im ag e in the sag itta l p lan e tha t is p e rpen d icu la r

to the ax ial p lane . H ow eve r , the se sag ittal reco nstruc tions

w ere no t fo und to be as he lp fu l in revea ling frac tu re -d is-

lo ca tion s o f the pe lv ic r ing as they have b een in d em on-

s tra ting iso lated ace tabu lar frac tu res .

Discussion

S tab ility o fthe pe lv ic rin g is d ep en den t on th e stru c tu ra l

in teg rity o f th e pos ter io r e lem en ts , in clu d ing the sac ro -ilia c

jo in t. the sac rum , the ilium , an d the ad jo in in g ligam en t

structures’. The po ste rosupe rio r sac ro -ilia c ligam en t co rn -

p lex p lay s an espec ially im po rtan t supp orting ro le. C orn -

p le te d isrup tio n of on e o r m o re o f th ese os seous o r

liga rnen tou s com pon en ts re su lts in an unstab le hem ip e lv ic

fragm en t. L esser in ju r ie s , su ch as an iso la ted ru p tu re o f th e

an te r io r sacro -iliac ligam en t o r a ha irlin e fractu re th rou gh

th e sacra l fo ra rn en , a re m in im ally d isp laced an d essen tia lly

stab le . W ith com ple te po ste rio rd isrup tion ofthe pe lv ic rin g ,

how ev er , d isp lacem en t o f th e h e rn ip e lv is m ay occu r in th ree

p lanes. M os t p atte rns o f in ju ry invo lve cep ha lad . p oste rio r,

and ex te rn al ro ta to ry d isp lacem en t’ . W hile n o qu an titativ e

criter ia fo r p elv ic stab ility hav e been un ive rsa lly accep ted .

it h as been gene ra lly ag reed th a t an y d eg ree o f cepha lad or

po ster io r d isp lacem en t o f the h em ipe lv is is d iagn ostic o f an

u nstab le le sio n6 .

A standa rd rad iog raph ic stu dy o f a traum atized pe lv is

inc lud es an te ropo ste rio r , in le t (x -ray beam d irec ted 3 0 to

45 deg rees caudad) , and tilt rad iog raphs (x -ray beam di-

rec ted 30 to 45 d egrees cepha lad ) . T he in let rad iog rap h

v isu alize s the an te rio r asp ect o f the sacra l pa rs la tera lis , the

sacro -ilia c jo in t, an d the ad jacen t pa rt o f the ilium , and can

be used to d e tec t an teropo ste rio r d isp lacem en t o f the h em i-

pe lv is . T h e tilt rad io g rap h d isc lose s the ex ten t o f cepha lad

d isp lacem en t. N one ofthese standa rd rad io g rap hs, h ow ev er .

dem onstrate the s tatu s o f the po ste rio r aspect o f the sac ro -

ilia c jo in t, the am oun t o f com m inu tio n of a sac ra l o r sacro -

ilia c frac tu re , o r the true am oun t o f ro ta tion o f th e hem i-

p e lv ic fragm en t. T hus , w h ile som e in fe ren ce co ncern in g

p e lv ic stab ility is fea sib le , a p rec ise de fin ition o f th e in ju ry

is ra re ly a tta inab le from these s tan dard rad iograp hs.

Com pu ter ized tom og raph ic scans appea r to o ffe r sev -

e ral d is tinc t adv an tag es ove r ro u tine rad io g rap hs. Th ese in -

d ude : ( 1 ) an unobs tru cted c ross-sectio na l im age o f the

seve rity o f th e po ste rio r in ju ry to the p elv ic r ing ; (2 ) a c lear

d isp lay of th e sp atia l o r ien tatio n an d p lanes o f d isp lacem en t

o f th e h em ipe lv is ; (3 ) a de ta iled p ic tu re o f any ace tabu la r

in vo lv em en t; an d (4 ) in pa tien ts trea ted b y in te rna l f ixa tion .

an accu rate w ay to ev alu ate th e adequ acy of frac tu re re -

duc tion , the p lacem en t o f im p lan ts . and th e p rog re ss o f

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FIG. 3-B

38 KEV IN G ILL AND R . W . BUCHO LZ

THE JOURNAL OF BON E AND JO INT SU RG ERY

Th is an te rop osterio r rad iog rap h of a tw en ty-f ive -ye ar-o ld v ict im o f a m otor-v eh icle ac cid en t show s a se em ing ly in tact p elv ic ring .

Th e com puted-tom ograph y scan , how ev er. d em ons tra tes a prev io us ly unsuspec ted lo ck ed sacro-il iac jo in t. E x tens ive com m inution o f th e po ste rio r

p art o f the sacrum was also n oted .

hea ling of th e frac tu re .

Th e deg ree o f po ste rio r d isrup tion o f th e pe lv ic r ing is

inva riab ly un de re stim ated on p la in rad iog raphs (F igs. 3 -A

and 3-B ). W hile frac tu re s o f th e sac rum o r ilium and sub-

luxa tio ns o f th e sac ro -ilia c jo in t ar e gene ra lly d etec tab le ,

the ex ten t o f com m inu tion is o ften le ss ev id en t. F rac tu re

comm inu tio n o ccurs m ost frequen tly a lon g the an te rio r a s-

pec t o f the sacro -iliac jo in t and th ro ugh th e th in ned cortice s

a long the sac ral fo ram ina2 9 . O ccasiona lly th e en tire sac ra l

pa rs late ralis w ill be fragm en ted . In th ree pa tien ts in o ur

ser ie s the comm inu tion w as jud ged on the com puted -tom og-

raph y scan s to b e to o ex ten sive to pe rm it sa tisfac to ry in te rn al

f ixa tion , an d ex terna l f ixa tion w as chosen as an a lterna tive

treatm en t. Po ste rio r lo ck ing of th e an ter io r lip o f the ilium

beh ind th e sac ral po rtion o fth e sac ro -ilia c jo in t w as app a ren t

in th ree o f o ur tw en ty -five p a tien ts . W hile such lo ck ing m ay

b e seen on a standa rd in le t rad iog raph of the p elv is , th is

o bscu red portion of the jo in t is d ifficu lt to ana lyze rad io -

g raph ical ly .

Th e ax ial transv erse cu ts o f the com puted -tom ography

scan can prov id e ind ispu tab le ev id en ce of frac tu re

d isp lacemen t5 . A nte ropo ste rio r an d ro tatio na l m a lpositio n

a re espec ially w e ll de linea ted . In th e ir c las sifica tion o f p el-

v ic d is rup tions , P en na l e t a l. d is tin gu ished b etw een s tab le

an te ro poste r io r an d late ral com press ion in ju rie s and un stab le

ve rtica l-shear in ju r ies , b a sed o n an ev a lu a tion of the sta tu s

o f th e po ste rosupe rio r sac ro -ilia c ligam en t com plex and the

re la tive po sitions o f th e h em ipe lv ic fragm en ts . Four o f ou r

tw en ty -five p atien ts w ere in itia lly ju dg ed to have com pres-

sion in ju r ies on the basis o f a s ing le an te ropo ster io r rad io -

g rap h , bu t late r th e in ju rie s w ere recla ssif ied as uns tab le

ve rtica l-sh ea r fractu re s because o f th e com ple te pos te r io r

in ju ry seen o n th e com puted -tom ography scans. T he p lans

fo r de fin itive trea tm en t in th ese fo u r p a tien ts w ere a lte red

acco rd ing ly . T he re su lts o f th is com para tive stu dy have

prom pted u s to jud ge and trea t all pe lv ic in ju rie s o n th e

basis o f th eir spec ific pa tho log ica l ana tom y ra th er th an b y

a p re sum ptiv e d iagn osis o f the m echan ism of in ju ry .

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COM PUTER IZED TOMOGRAPH IC SCANNING IN THE EVALUATION OF M A JOR PELVIC FRACTURES 39

VOL . 6 6-A , NO . 1 , JA NU ARY 19 84

Ace tabu la r d is rup tions frequ en tly accom pany p elv ic

r ing in ju rie s . W hile inv o lvem en t o f the h ip jo in t is u sua lly

ob v iou s o n p la in rad iog raph s, com pu ted -tom og raph y scans

id eally o u tline the degree o f frac tu re comm inu tio n and ace -

tab u la r incon gru ity47 . C om pute r ized tom og raph ic stu d ie s

g rea tly fac ilitate th e p reo pe ra tive p lann in g o f su rg ical ap -

p roaches.

O p en reduc tio n and in terna l fixa tion is occas iona lly thep refe rred treatm en t fo r an u nstab le pe lv ic -rin g in ju ry9 . P o st-

op era tive d ec ision s co ncern in g m obilizatio n of the pa tien t

an d w eig h t-b earing m ust be based o n a c lin ical judgm en t

at the tim e of ope ratio n o f the adequ acy of the f ixa tion and

th e phase o f os seous hea ling a t any g iven po in t in tim e .

The ex ac t loca tio n and pu rchase o f screw th reads a re o ften

d iff icu lt to de term in e o n p la in rad io g rap hs, bu t a re easily

seen on com puted -tom ograp hy scans. A n unsa tisfac to ry p o-

sitio n o f the screw s in the reg io n o f com m inu tion of the

frac tu re w as th ough t to com prom ise fractu re f ixa tion in th ree

p atien ts in ou r se r ies . C a llu s fo rm a tion an d bone -rem od e ling

a lso w ere c lea rly v isua lized on th e com pu ted -tom og raph y

scans th at w ere ob ta ined tw o to six m on th s af te r in ju ry .

B ased on the re su lts o f th is s tudy , w e recomm end the

use o f ad junc tive com puted -tom ograp hy scan s in the eva l-

ua tion of m a jo r p elv ic-r ing in ju r ies w hen th ere is a d oub le

vertical frac tu re o r su b luxa tion of the hem ip elv is in w hichan te ropos te r io r , in le t, and tilt rad iog raphs cann o t co nc lu -

sive ly d em ons tra te the stab ility o f th e in ju ry ; w hen th e re is

an ilia c frac tu re w ith ex ten sion in to o ne o r bo th ace tabu la ;

an d w hen m ajo r in ju r ies o f th e hem ipe lv is are to be trea ted

by open redu c tio n an d in te rn al fixa tion of th e p oste r io r p a rt

o f th e p elv ic r ing . H ow ev er , du e to the cost and rad ia tion

ex posu re o f p elv ic com pu ted -tom ograp hy scan s, ro u tine

scann ing of all pa tien ts w ith p elv ic-rin g in ju r ies is n o t

ju st i f ied .

References

1 . BU CHOLZ , R . W .: Th e Patho log ica l A na tom y of M a lga ign e F rac ture-D isloca tions o f th e Pelv is . J . B one and Join t Surg. . 63 -A: 400-404 . Mar ch

1981 .2. HOLD SWORTH , F . W .: D is loca tion and F ra ctu re-D is location of th e Pe lv is. J . Bone and Join t Surg. . 30-B (3 ): 461-4 66, 1948.

3 . HUNDLEY , J. M . : U nunite d U n stab le F racture s of the Pe lv is. In P roc eed in gs o f The Am er ican Academ y o f O rth opaed ic Su rgeon s. J . Bon e and

Jo in t Su rg . , 48 -A : 1 025 , Ju ly 1966 .

4 . LANGE , T . A . . an d A LTER , A . J. . JR . : Ev alu atio n o f Com p lex A cetabu lar F racture s by Com puted Tom ograph y . J. C om put. A ss ist. T om og . . 4:

849 -85 2 , 198 0 .

5. LAWSON , T . L .; FOLEY . W . D. ; CARRERA . G . F .; and BER LAND . L . L .: Th e Sacroilia c Jo in ts : Anatom ic, P la in Roentgen og rap h ic and Com pu ted

Tom ographic A nalysis. J . C om put. A ssis t. T om og. , 6 : 3 07 -31 4 . 19 82 .

6. P EN NA L , G . F .: T IL E , M ARV IN ; W ADDELL , J. P .; and GAR5 ID E , H EN RY : Pelv ic D isrup t ion : A sse ssm ent and C las sification . C lin . O r tho p .. 1 51 : 1 2-

2 1, 1 980.

7. SH IR KHO DA , A L l; B RA SHEAR , H . R . ; an d S TA A B . E . V . : C om pu ted Tom ography of A cetabu lar F ra ctu res . R ad iology , 1 34 : 683-688. 1 980.

8 . SLAT1 s. P . , an d HU ITTINEN , V .-M .: Doub le V ert ica l Fra ctu res of the P elv is. A R epor t on 163 P atien ts. A c ta C hir. S candinav ica , 138: 7 99 -807,

1972 .

9. T IL E, M ARV IN : Pe lv ic F racture s: O pe rative V e rsus N onop era tive T re atm en t. O r tho p . C lin . N o rth Am erica , 11 : 423-464 , 19 80 .