Fractures of the Acetabulum Accuracy of Reduction and Clinical Results

7/28/2019 Fractures of the Acetabulum Accuracy of Reduction and Clinical Results

1/14


2/14

F R A C T U R E S O F T H E A C E T A B U L U M : A C C U R A C Y O F R E D U C T I O N A N D C L I N I C A L R E S U L T S 1633proto col establishe d in 1980; sep ara te com puter fileswere used for the initial and follow-up data. Completeinitial data were available for all 381 patients (386 hips);however, 122 pat ients (124 hips) had had inadequatefollow-up and I was unable to contact any of them foraddit ional evaluat ion. Two hundred and sixty-two hipsin 259 pat ients (three of whom had a bi lateral fracture) had been followed adequately, and the initial andfollow-up data for these patients form the primary basisfor this report . Hips were judged to have had adequatefollow-up if they had been followed for a minimum oftwo years (255 hips) or, if not, they had had a clearlypoor clinical result before two years (seven hips).Demo graphic Data and Fracture Types

The study included 184 male patients and seventy-five female pat ients . One hundred and six right acetab-ula (40 per cent) and 156 left acetabula (60 per cent)were fractured. The ages of the pat ients ranged fromeleven to ninety years (mean, thirty-seven years). Onehund red and forty-seven pat ients (56 per cent) werefrom tw enty throu gh thirty-nine yea rs old; only twenty-nine pat ients (11 per cent) were sixty years old ormore. The most common mechanisms of injury were amotor-vehicle accident (181 pat ients; 70 per cent), amotor vehicle-pedestrian accident (thirty-four pat ients;13 per cent), and a fall (thirty-five patients; 14 percent). (The nine remaining pat ients had other mechanisms of injury.)

On e hun dred and forty-eight fractures (147 pat ients;56 per cent) w ere associated with at least one addit ionalinjury. Fifty-one fractures (19 per cent) were associatedwith a head injury; twenty (8 per cent), an abdominalinjury; forty-eight (18 per c ent), a chest injury; sev entee n(6 per cen t), a genito-urinary injury; ninety-one (35 percent ) , an injury involving an extremity; eleven (4 percen t), an injury of the spine; and thir ty-thr ee (13 percen t), a nerve palsy. Thirty-four fractures (13 per cent)were associated with more than two injuries; fifty (19pe r ce nt), with tw o; and sixty-four (24 per ce nt), withone. The rem aining 114 fractures (44 per cent) w ere n otassociated with other injuries.All pat ients were ini t ial ly evaluated with use ofthree standard plain radiographs (one anteroposteriorradiograph and two 45-degree oblique radiographs ofthe pelvis [Judet radiographs])4 '81 2. Computer ized to

mog raphy was perform ed on all pat ients who were managed after 1983. Although compu terized tomog raphicscans and three-dimensional reconstruct ions of thescans were made for many pat ients , they were not usedto determine the need for operat ive t reatment or in theanalysis of the results. The d isplacem ent of the fracturewas measured separately. The maximum displacementseen on each of the three radiographs was recordedwithout adjustment for magnification. If it is assumedthat the maximum displacement seen on any of theradiographs was the most accurate measure of displace

ment, then displacement ranged from five to seventymillimeters and averaged twenty millimeters.With use of the initial radiographs, the fractureswere classified according to the criteria of Letourneland Judet12 . Of the 262 fractu res, fifty-four (21 pe r ce nt)were simple fracture types and 208 (79 per cent) wereassociated fracture types. Th e simple fracture type s included three anterior wall fractures (1 per cent), twelve

anterior column fractures (5 per cen t), twenty-two posterior wall fractures (8 per ce nt), eight posterio r colum nfractures (3 per cent), and nine t ransve rse fractures (3per cen t). The associated frac ture types included tenposterior colum n-posterior wall fractures (4 per cent),sixty transverse-posterior wall fractures (23 per cent),thirty-o ne T-shaped fracture s (12 per cen t), fifteen anterior column-posterior hemitransverse fractures (6 percent), and ninety-two both-column fractures (35 percent). There was one open fracture. The distribution ofthe fractures, with associated patterns accounting for79 per cent, reflects the fact that 246 patients (95 percent) were transferred to my care from other hospitalsbecause of the need for operat ive t reatment and thecomplexity of the fracture.

Eighty-three hips had a posterior dislocat ion andone had an anterior dislocation. Of the eighty-three po sterior dislocat ions, twenty-one were reduced closed before the operat ion and sixty-two were reduced at thet ime of the operat ion. Preoperat ive t ract ion was usedfor only a few patients for whom the operation wasdelayed after they were admitted to my institution; itwas used to preve nt posterior dislocat ion or wear of thefemoral head against a transtectal T-shaped or transverse fracture.Operative Technique

On the basis of the classification and the specificconfiguration of the fracture, and according to the recommendations of Letournel and Judet12 , a single operat ive approach was selected; i t was expected that theentire reduct ion could be performed with use of oneapproach. The Kocher-Langenbeck approach, in whichthe pat ient is posi t ioned prone on the Judet table, wasused in 112 hips (43 pe r cent) ; the ilioinguinal a ppr oac h,in which the patient is positioned supine on the Judettable, was used in eighty-seven (33 per c ent) ; and theextended i l iofemoral approach, in which the pat ientis positioned laterally on the Judet table, was used infifty-nine (23 per c ent). The goal of the opera tion wasto achieve an anatomical reduct ion of the innominatebone and the art icular surface of the acetabulum. TheKocher-Langenbeck and i l ioinguinal approaches wereconsidered preferable to the extended i l iofemoral approach because they involve less stripping of musclefrom the innominate bone and the femur; the extendedil iofemoral approach was chosen only when an anatomical reduct ion was judged to be probably impossiblewith use of one of the other two approaches alone. InV O L . 7 8 - A , N O . 1 1 , N O V E M B E R 1 9 96


3/14

1634 J. M. MATTAT A B L E I

O P E R A T I V E A P P R O A C H FOR E A C H F R A C T U R E T Y P E * !Operative Approach

Extended Kocher-LangenbeckFracture Type Kocher-Langenbeck I l ioinguinal I l iofemoral and IlioinguinalAnterior wall (n = 3) 3Anterior column (n = 12) 11 1Posterior wall (n = 22) 20 (91 % ) 2 (9%)Posterior column (n = 8) 8Transverse (n = 9) 8 1Posterior column-posterior wall (n = 10) 10Transverse-posterior wall (n = 60) 46 (77%) 13 (22%) 1 (2%)T-shaped (n = 31) 1 9 ( 6 1 % ) 4 ( 1 3 % ) 6 ( 1 9 % ) 2(6%)Anterior column-posterior 14 1hemitransverse (n = 15)Both-column (n = 92) 1( 1%) 5 4 ( 5 9 % ) 3 6 ( 3 9 % ) 1(1%)Entire series (n = 262) 112(43% ) 87 (3 3%) 59 (2 2% ) 4(2%)

*As recommended by L etourne l and Judet12 .t All values are given as the numbers of hips.four hips (2 per cent ) , an ini tial Kocher-Langen beck ori l ioinguinal approach was inadequate to complete thereduct ion and fixation and a combined ilioinguinal andKocher-Langenbeck approach was used121417, during thesame session of anesthesia.

For six fracture types, the choice of the operat iveapproach was consistent . The ilioinguinal approach wasused for anterior wall , anterior column, and anteriorcolumn -posterior hem itransverse fractures. The K ocher-Langenbeck approach was used for posterior wall ,posterior column, and posterior column-posterior wallfractures (Table I). The operat ive approach for the fourremaining fracture types was chosen according to thespecific fracture pattern as follows.Transverse fractures: The Kocher-Langenbeck ap-proach is usually chosen. If the fracture line crosses theacetabulum from proximal anterior to distal posteriorand the displacement is greatest anteriorly, the ilioinguinal approach is selected.Transverse-posterior wall fractures: In most pat ients ,the Kocher-Langenbeck approach is employed. If thesurgeon expects unusual difficul t ies with reduct ion,the extended i l iofemoral approach may be selected.Transverse-posterior wall fractures are often difficultto reduce when they include a t ranstectal t ransversecomponent , when there is an extended posterior wallfracture (involving the pos ter ior border of the b o n e) ,when they consist of T-shaped and posterior wall fractures, and when they are associated with dislocation ofthe symphysis pubis or fracture of the contralateral pu-bis ramus.T-shaped fractures: Usually, the Kocher-Langenbeckap p ro ach is chosen . If the surgeon expects unusualdifficulties with reduction, the extended i l iofemoral ap-proach may be selected. T-shaped fractures that are of-ten difficult with regard to reduct ion include those witha t ranstectal t ransverse component , those with a wideseparat ion along the vertical stem of the T, and those

associated with dislocation of the symphysis pubis orfracture of the contralateral pubic ramus.Both-column fractures: These fractures are m o s tfrequently t reated through the i l ioinguinal approach.If the reduct ion is expected to be unusually difficult,the ex tended i l io femoral approach is chosen . Both-column fractures that include a complex fracture ofthe posterior column, a displaced fracture line crossin g the sacro-iliac joint, or a wide separat ion of theanterior and posterior columns at the rim of the acetabulum are often difficult to reduce.The Judet table was not available until 1985 but wasused consistently after that time. Before 1985, A M SC O(Am erican Steril izer Company, Erie, Pennsylvania) andKirschner fracture tables were used. The table is used to

position the extremity securely, with distal and lateralt ract ion applied to the femoral head in order to facilitate reduct ion and visualization of the acetabulum.The reduction was performed by direct manipulation of the bone with special reduct ion instruments;the goal was to achieve an anatomical reduct ion of theinnominate bone and the acetabulum. The fixation wasperformed with plates and screws in 226 hips (86 percent) and with screws alone in thirty-six (14 per cent)7,1213.Screws alone were used when the fracture divided theinnom inate bon e into large segments, as in high anteriorcolumn fractures or simple-pat tern both-column fractures. A fracture of the poste rior wall was not consideredan indication for fixation with screws alone. Fixationwith interfragm entary screws, with the reduct ion heldwith reduct ion forceps or clamps, was usually performedbefore definitive fixation with a plate. Provisional fixation with Kirschner wires was not used.The loss of blood and the durat ion of the operation varied according to the operat ive approach. TheKocher-Langenbeck approach was associated with amean blood loss of 900 milliliters (range, 100 to 3500milliliters); the ilioinguinal approach, with a m ean of

THE JOURNAL OF BONE AND JOINT SURGERY


4/14

F R A C T U R E S O F T H E A C E T A B U L U M : A C C U R A C Y O F R E D U C T I O N A N D C L I N I C A L R E S U L T S 16351366 milliliters (range, 300 to 6000 milliliters); the extend ed i l iofemoral approa ch, with a mean of 1642 mil li liters (range, 500 to 3500 milliliters); and the combinedKocher-Langenbeck and i l ioinguinal approach, with ame an of 2025 milliliters (rang e, 1400 to 2700 milliliters).The mea n d urat ion of the operat ion was 2.4 hours (range,one to eight hours) with use of the Kocher-Langenbeckapproa ch, 3.4 hours (range, one to twelve hours) w ith useof the ilioinguinal approach, 4.1 hours (range, two toseven hours) with use of the extended iliofemoral approach, and 6.3 hours (range, four to seven hours) withuse of the combined Kocher-Langenbeck and i l ioinguinal approaches .

The operative findings included intra-articular freefragments in seventy-five hips (29 per cent); associatedinjury to the cartilage or the bone of the femoral head,or both, in fifty hips (19 per cent); and acetabular articular impaction in thirty hips (11 per cent).Postoperat ively, immobil izat ion or t ract ion was notused. Walking with thirty pounds (13.6 kilograms) ofweight-bearing on the ipsilateral extremity was usuallybegu n during the fi rs t week after the operat ion, depe nding on the severity of pain and the associated injuries.Full weight-bearing was allowed eight weeks after theoperat ion .The mean interval between the injury and the operat ion was nine days (range, zero to twenty-one days).The m ean du rat ion of hospital izat ion was nineteen days(range, three to 137 days; median , eighteen da ys).A uniform protocol for prophylaxis against deepvenous thrombosis was not established until 1990; at thatt ime, i t included use of continuous external pneumatic-compression devices for both lower limbs and administrat ion of Coumadin (warfarin) beginning forty-eightto seventy-two hou rs after the oper at ion and continuingfor forty days1. No prophylaxis against hete rotopic ossification was used.Data Collection

The telephone numbers and addresses of the patients were recorded as part of the initial collection ofdata . At tempts were made to contact , by te lephoneand by letter, patients who did not return for follow-up . Patients were assured that the fol low-up examination could be performed free of charge and, if necessary,they could be reimbursed for costs of t ransportat ion.A few pat ients had moved to a distant locat ion thatpreclude d ex amination in Los Angeles. Those pa t ients ,i f they could be contacted, were interviewed by telephone, and a cl inical examinat ion was performed andan anteroposterior radiograph of the pelvis was madeby another or thopaedic surgeon, who was re imbursedthro ugh funds allocated for this study. I assessed th efol low-up radiographs for those pat ients .Clinical and radiographic examinat ions were performed and data were reco rded at six months, one year,and two years; thereafter, they were performed annually

if the patient had osteoarthrosis or every two years ifno or only slight problems were identified. Only a fewpatients were examined at all of the follow-up intervals, but all were seen at the final interval and the datafrom that exam inat ion were used for this repo rt . At thelatest follow-up exam ination, separa te radiographic andcl inical grades were assigned. According to the radiographic criteria, a grade of excellent indicates a normalappearance of the hip; a grade of good, mild changes,small osteophytes, mo dera te (one-mil l imeter) n arrowing of the joint, and minimum sclerosis; a grade of fair,in termediate changes, mo derate os teophytes , moderate (less than 50 per cent) narrowing of the joint, andmo der ate sclerosis; and a grade of poor , advancedchanges, large osteophytes, severe (m ore tha n 50 percent) narrowing of the joint, collapse or wear of thefemoral head, and acetabular wear. The cl inical gradewas based on a modification of the system of Merled'Aubigne and Postel that I have used in previousstudies (Table II)1518 . The modification involves a morestrict grading of the score for the range of motion of thehip, which is determined by comparison of the totalscore for the injured side with that for the uninjuredside. Flexion, abduction, and a dduction w ere evaluatedwith the pat ient supine, and rotat ion was evaluated withthe pat ient prone. Limitat ions in extension were subtracted from the measurement of flexion, to give a singlescore for flexion-extension.

The score of Merle d 'Aubigne and Postel includesone subjective assessment for pain. The patient was interviewed by the examining surgeon, and the score wasbased on the responses to s ix quest ions:1. Do you have any pain?2. If you have pain, does i t require medicat ion?3. Are there any act ivi t ies that you can' t do nowbut could do before the acetabular fracture?4. Can you sit for a prolonged period of time, ordoes hip pain or s t i ffness require moving atintervals?5. Do you participate in sports or exercise activities,and are you limited in these?6. Do you work, and did you return to your pre-injury occupation?Patients who reported no problems in response to thesequestions were assigned a score of 6 points. Severalpat ients who part icipated in very high-demand sportsactivities (marathon running, triathlons, or universityvarsity sports) and had a decrease in perform ance afterthe injury also received a score of 6 points. A score of5 points was assigned to patients who had mild or interm ittent sy mp toms or limitations that is, pain ordiscomfort associated with rigorous act ivi ty but notnec essita ting analge sics, stiffness after sitting for oneor two hours, and aching or stiffness associated withchanges in the weather. Pat ients who needed pain medication or had pain that limited walking or work activities received a score of 4 points or less.

V O L . 7 8- A , N O . 1 1 , N O V E M B E R 1 99 6


5/14

1636 J. M. MATTAT ABL E I I

C L I N I C A L G R A D I N G SYSTEMPoints

PainN o n eSlight or intermittentAfter walking but resolvesModerately severe butpatient is able to walkSevere, prevents w alkingWalkingNormalNo cane but slight limpLong distance with cane or crutchLimited even with supportVery limitedUnable to walk

Range of motion*95-100%80-94%70-79%60-69%50-59%


6/14

FRACTURES OF THE ACETABULUM: ACCURACY OF REDUCTION AND CLINICAL RESULTS 16 37T ABL E I I I

D I S T R I B U T IO N O F T H E Q U A L I T Y O F T H E R E D U C T I O N A C C O R D I N G T O F R A C T U R E T Y P E ,A G E O F TH E P A TI EN T, A N D I N I TIA L D I S P LA CEM EN T O F TH E F RA C TU RE*

Fracture typeSimple (n = 54)

Anterior wall (n = 3)Anterior column (n = 12)Posterior wall (n = 22)Posterior column (n = 8)Transverse (n = 9)Associated (n = 208)Posterior column-posterior wall (n = 10)Transverse-posterior wall (n = 60)T-shaped (n = 31)Anterior column-posteriorhemitransverse (n = 15)Both-column (n = 92)

A ge11-19 yrs.(n = 19)20-29 yrs. (n = 76)30-39 yrs. (n = 71)40-49 yrs. (n = 39)50-59 yrs. (n = 28)60-69 yrs. (n = 20)70-90 yrs. (n = 9)

Initial displacement5-10 mm (n = 97)11-20 mm (n = 97)21-30 mm (n = 46)31-70 mm (n = 22)

Anatomical

31222 (100%)78

1048 (80%)16 (52%)

752 (57%)1860 (79%)52 (73%)25 (64%)1 7 ( 6 1 % )7 (35%)

674 (76%)64 (66%)34 (74%)13 (59%)

Quality i

Imperfect

11

10 (17%)10 (32%)6

24 (26%)1

12 (16%)13 (18%)9 (23%)6 (21%)8 (40%)3

19 (20%)19 (20%)9 (20%)5 (23%)

of Reduction

Poor

2 (3%)5 (16%)29 (10%)

4 (5%)6 (8%)3 (8%)3 (11%)2 (10%)

12 (12%)2 (4%)4 (18%)

SurgicalSecondaryCongruence

7 (8%)

2 (5%)2 (7%)3 (15%)

4 (4%)2 (2%)1 (2%)

*A11 values are given as the numbers of hips.teen years) (when the seven pat ients who had a poorresult and less than two years of follow-up were excluded). The over-all clinical result for the 262 hips wasexcellent for 104 (40 per c ent), good for ninety-five (36per cent), fair for twen ty-one (8 per cent), and poor forforty-two (16 per cent).

Fracture TypeForty (74 per c ent) of the fifty-four hips that had asimple fracture pattern had either an excellent or a goodclinical result at the latest follow-up evaluation, compared with 159 (76 per cent) of the 208 that had anassociated fractu re pa ttern (Table IV). The type of fracture pat tern (simple or associated) was independent ofthe clinical result (chi squ are = 3.522; p = 0.32), as wasthe specific frac ture type (chi squ are = 35.792; p = 0.12).How ever, t reatme nt of the T-shaped-posterior wall fracture type (fourteen hips) was associated with the highestprevalence of poor results (three excellent, five good,one fair, and five poor).Posterior DislocationFifty-nine (71 per ce nt) of the eighty -three hips thathad a posterior dislocation of the femoral head hadeither an excellent or a good clinical result, comparedwith 140 (78 per cent) of those that did not have a

posterior dislocation. With the numbers available, thisdifference was not significant (p = 0.18).Initial DisplacementThe mean ini t ial displacement of the fractures waseighteen millimeters in the hips that subsequently hadan excellent result, twenty-one millimeters in those thathad a good result, seventeen millimeters in those thathad a fair result, and twenty-three millimeters in thosethat had a poor resul t . With the num bers avai lable, thesedifferences were not significant (p = 0.28).Associated InjuriesThe clinical results for the patients who had associated injuries were similar to those for the patients who

did not. Of the 148 hips in the 147 patients who hadassociated injuries, fifty-nine (40 per cent) ha d an excellent resu lt; fifty-four (36 pe r cen t), a good r esu lt; fourteen (9 per cent), a fair result; and twenty-one (14 percent), a poor result. Of the 114 hips in the 112 patients who did not have associated injuries, forty-four(39 per cent) had an excellent result, forty-one (36 percent) had a good result, seven (6 per cent) had a fairresult, and twenty-two (19 per cent) had a poor result.The presence of a head injury did not adversely affectthe clinical score.VOL. 78-A, NO. 11, NOV EMBE R 1996


7/14

1638 J. M. MATTAT A B L E IV

DI S TRI BUTI ON OF THE CL INICAL R E SUL T S ACCO R DING TO F R A C T U R E T Y P E , Q U A L I T Y OF THE R E D U C T I O N , AND R A D I O G R A P H I C G R A D E *

Fracture typeSimple (n = 54)

Anterior wall (n = 3)Anterior column (n = 12)Posterior wall (n = 22)Posterior column (n = 8)Transverse (n = 9)Associated (n = 208)Posterior column-posterior wall (n = 10)Transverse-posterior wall (n = 60)T-shaped (n = 31)Anterior column-posteriorhemitransverse (n = 15)Both-column (n = 92)

Entire series (n = 262)Quality of the reduction

Anatomical (n = 185)Imperfect (n = 52)Poor (n = 18)Surgical secondary congruence

Radiographic gradeExcellent (n = 141)Good (n = 59)Fair (n = 29)Poor (n = 33)

Excellent

199 (41%)25721 (35%)6 (19%)8

36 (39%)104 (40%)

82 (46%)17 (33%)

3282 (58%)21 (36%)1 (3%)

Clinical ResultGood

116 (27%)33221 (35%)

18 (58%)5

35 (38%)95 (36%)68 (37%)18 (35%)

6349 (35%)32 (54%)13 (45%)

1 (3%)

Fair

1121

5 (8%)2 (6%)19 (10%)

21 (8%)10 (5%)

7 (14%)226 (4%)3 (5%)7 (24%)5 (15%)

Poor

17 (32%)1

113 (22%)

5 (16%)112 (13%)42 (16%)25 (12%)10 (18%)7

4 (3%)3 (5%)8 (28%)27 (82%)

*A11 values are given as the numbers of hips.

Damage of the Femoral HeadOf the fifty hips that had damage of the femoralhead, thirty (60 per cent) had an excellent or a goodclinical result, compared with 169 (80 per cent) of the212 hips that did not have such damage. The mean clinical score2"51 8 for the patients who had damage of thefemoral head was 14 points (range, 5 to 18 poin ts), significantly less (p = 0.01) than the mean score of 16points (range, 4 to 18 points) for those who did not havesuch damage.Intra-Articular Fragments andAcetabular ImpactionThe mean clinical score for the seventy-five hips thathad intra-art icular fragments was 15 points (range, 5to 18 points), compared with 16 points (range, 4 to 18points) for those that did not have such dam age. With thenumbers available, this difference was not significant(p = 0.15).The mean clinical score for the thirty hips that hadacetabular art icular impaction was 15 points (range, 7to 18 points), compared with 16 points (range, 4 to 18points) for those that did not have impaction. With thenumbers available, this difference was not significant(p = 0.21).Ag eThe pat ients were divided into two groups thosewho were forty years old or m o re and those who were

less than forty years old to determine whether therewas a relat ionship between the clinical result and theage-group. Of the 166 hips in patients who were lessthan forty years old, 134 (81 per cent) had an excellentor good result, compared with only sixty-five (68 percent) of the ninety-six hips in patients who were fortyyears old or more. This difference was significant (chisquare = 5.641; p = 0.02). However, when the variableof quality of the reduct ion was control led for, the age-group was found to be independent of the clinical result. An excellent or good clinical result was associatedwith 110 (85 per cent) of the 130 anatomical reduct ionsin the younger age-group, compared with forty (73 percent) of the fifty-five such reductions in the older age-group. An excellent or good clinical result was associated with eighteen (69 per cent) of the twenty-siximperfect reduct ions in the younger age-group, compared with seventeen (65 per cent) of the twenty-sixsuch reductions in the older age-group. Such a result wasassociated with six of the ten poor reduct ions in theyounger age-group, comp ared with three of the eight inthe older age-group.ReductionWhen hips with a congruent reduct ion and thosewith an intra-articular infection were excluded, the quality of the reduct ion was strongly associated with theclinical res ult (chi square = 14.982; p = 0.02) (Table IV).Th ere was an even stronger associat ion between the

THE JOURNAL OF BONE AND JOINT SURGERY


8/14

F R A C T U R E S O F T H E A C E T A B U L U M : A C C U R A C Y O F R E D U C T I O N A N D C L I N I C A L R E S U L T S 1639clinical results associated with an anatomical reductionand those associated with imperfect and poor reductions combined. This is because, with the numbers available, the clinical results associated with the imperfectreductions did not differ significantly from those associated with the poor reduct ions. An anatomical reduction was strongly associated with an excellent or goodresult (chi square = 9.910; p = 0.002) (Table IV). Of theseven hips that had surgical secondary congruence, twohad an excellent clinical result, three had a good result,and two had a fair result. Postoperatively, the femoralhead w as judged to be congruen t with the acetabularroof in 250 (95 per cent) of the 262 hips; of these 250hips, 102 (41 per cent) had an excellent clinical result,ninety-two (37 per cent) had a good resul t , nineteen (8per cent) had a fair result, and thirty-seven (15 percent) had a poor resul t . The operat ion did not resul t incongruence in the remaining twelve hips (5 per cent);two had an excellent clinical result, three had a goodresult, two had a fair result, and five had a poor result.I t fol lows that postoperat ive congruence with the acetabular roof is a strong predictor of the clinical result(chi square = 8.450; p = 0.04).

Postoperat ive incongruence was observed in twelveof the seventy-seven hips that had an imperfect or apoor reduction. Of the sixty-five hips in this group thathad co ngru enc e, forty-four (68 per ce nt) had an excellent or good clinical result, compared with five of thetwelve that did not have congruence.Radiographic Grade

Of the 262 hips, 141 (54 per cent) had an excellentradio grap hic result, fifty-nine (23 per cen t) had a goodresult, twenty-nine (11 per cent) had a fair result, andthirty-three (13 per cent) had a poor resul t (Table IV).There was a s trong associat ion between the radiographic grade and the cl inical resul t (chi square =176.890; p = 0.00001) (Table IV ). O ne h undr ed andeighty-four (92 per cent) of the 199 hips that had anexcellent or good clinical result also had an excellent orgood radiographic resul t . There was a t rend in the cl inical scores relat ive to the radiogra phic grades. A radiographic grade of excellent was associated with a meanclinical score of 17 poin ts (ran ge, 8 to 18 poin ts); a gradeof good, with a mean clinical score of 17 points (range,8 to 18 points); a gra de of fair, with a me an clinical scoreof 14 points (range, 6 to 18 points); and a grade of poor,with a mean clinical score of 9 points (range, 4 to 15points). The rad iographic findings included narrowingof the joint in twenty hips (8 per cent), osteophytes inthirty (11 pe r cent) , wea r of the femoral head in th irteen(5 per cent), sclerosis in eight (3 per cent), and ectopicbone in 107 (41 per cent).Poor Clinical Results

Forty-two (16 per cent) of the 262 hips had a poorclinical result. Of these forty-two h ips, seve ntee n w ere

treated with a total hip replacement and four, with anarthrodesis . Thirteen hips had not had an addit ionaloperation at the time of writing, but total hip replacement or arthrodesis was considered appropriate forthese hips if requested by the patient. Eight hips had apoor resul t due to severe ectopic bone.Complications

Neurological injury (two sciatic-nerve palsies, onefemoral-nerve palsy, and six peroneal-nerve palsies) occurred during nine operat ions. The nerve palsies wereassociated with three Kocher-Langenbeck, two i l ioinguinal , two extended i l iofemoral , and two combinedKocher-Lan genbeck and i l ioinguinal approach es. In addition, a nerve palsy occurred secondary to the injury ofthirty-two hips. The clinical results for these forty-onehips were similar to those for the pat ients who did nothave palsy (thirty-on e [76 per cent] excellent and g oodresults and ten [24 per cent] fair and poor results, compared with 168 [76 per cent] excellent and good resultsand fifty-three [24 pe r cent] fair and po or re sults).A wound infection was a complication of the operation in thirteen hips (five of which had an extra-articularinfection and eight, an intra-articular infection). Allthirteen hips had had adequate fol low-up and were included in the study group. When infection was suspected, the pat ient was returned to the operat ing roomfor the remo val of specimens for culture , for irrigationand debridement , and for closure over suct ion drainage; ant ibiot ics were subsequently administered. No patient had an active infection or persistent drainage atthe latest follow-up examination. Four infections (allintra-art icular) developed after a Kocher-Langenbeckoperative approach; four (all extra-articular), after an

ilioinguinal approach; and five (four intra-articular andone extra-art icular), after an extended i l iofemoral approach. Six of the eight hips that had an intra-articularinfection had c omplete d estruct ion of the joint space anda poor clinical result. The remaining two intra-articularinfections were associated with one good result and onefair result. The five extra-articular infections were associated with three goo d and two fair resul ts . The meanclinical score of the patients who had an infection was12 points, compared with 16 points for those who didnot have an infection.Of the thirteen hips (5 per cent) that had wear ofthe femoral head, one had a fair clinical result andtwelve, a poor res ult. In ten of the thirtee n hips, the w earwas severe. Eight hips (3 per cent) had osteonecrosis ofthe femoral head; two of them had a good clinical resultand six, a poor result. Eighty-three hips (32 per cent)had a posterior dislocation; five (6 per cent) of them hadosteonecrosis. Wear of the femoral head was associated with five fracture type s: trans verse -pos terior wallfractures (five of sixty), both -colu mn fractures (four ofninety-two), posterior wall fractures (two of twenty-two), posterior column-posterior wall fractures (one of

V O L . 7 8 - A , N O . 1 1 , N O V E M B E R 1 9 96


9/14

1640 J . M . M ATTA%';

mt

'&';.

W

u_ i j . 1 . .

F I G . 1-AFigs. 1-A, 1-B, and 1-C: Radiographs of a forty-eight-year-old woman who had a both-column fracture of the right acetabulum.Fig . 1-A: Ante roposte rior and 45-degree oblique radiographs showing the fracture .

F I G . 1-BAnteroposterior and 45-degree oblique radiographs made after open reduction and internal f ixation, performed with the extendediliofemoral approach seven days after the injury. This approach was chosen because of a proximal posterior column fracture that entered thesacro-iliac joint. The reduction was graded as imperfect; there was two millimeters of displacement of the articular surface, best seen on theoblique radiograph of the iliac crest.

t en ) , and T-shaped fractures (one of thirty-one).Ectopic bone was either absent or slight in 216 (82pe r cen t) of the 262 hips, and it was pres ent w ith orwithout limiting motion in forty-six (18 per cent). Moderate or severe e ctopic bone, associated with at least

a 20 per cent loss of motion, developed in twenty-threehips (9 per cent). As previously reported 2912, there is avery s trong associat ion between the operat ive approachand the prevalence of this amount of ectopic bone. Thisamount of ectopic bone was noted after nine (8 perTHE JOURNAL OF BONE AN D JOINT SURGERY


10/14

FRACTURES OF THE ACETABULUM: ACCURACY OF REDUCTION AND CLINICAL RESULTS 1641t

/ ' /Irt

)=>_>

u F I G . 1-CSequ ential follow-up radiog raphs . Left: Five mo nths after the ope ratio n, the joint space was narrow ed seco ndary to wear of the cartilage.Center: At eight months, the femoral head was smaller and had migrated in a proximal direction secondary to wear of both the femoral headand the aceta bulum. Right: One year after the injury, a total hip replacement was performed with the Kocher-Langenbeck approach. A graftfrom the femoral head was used to fill a defect in the acetabular roof that had resulted from wear; the graft was fixed with two screws.

cent) of the 112 Koche r-Langenbec k approache s, twelve(20 per ce nt) of the fifty-nine e xten ded i l iofemoralapproaches, and two (2 per cent) of the eighty-sevenil ioinguinal approaches.Eight hips (3 per cent) had a partial loss of reductionof the fracture after the initial open reduction and internal fixation. The clinical result was excellent for oneof thes e hips, good for two, and po or for five. Re pe atopen reduction in three of these hips led to an excellentresult in one with a T-shaped fracture, a good result inone with a both-column fracture, and a poor result inone with a t ransverse-posterior wall fracture.There were no non-unions in this series .

Comparison of the Hips That Had AdequateFollow-up with Those That Did Not

In order to test the validity of the sample of the hipsincluded in this study, the initial data for the 262 hipsthat had adequate fol low-up was compared with suchdata for the 124 hips that did not have ad eq ua te follow-up. The eight factors chosen for comparison were age,fracture type, initial displacement, posterior dislocation,femoral h ead injury, operat ive approac h, reduct ion, andwound infect ion . Wi th the numbers avai lab le , therewas no significant difference between the two groupswith regard to four factors: distribution of the fracturetype s (chi squ are = 9.566; p = 0.39), redu ction (chi

squa re = 4.845; p = 0.18), age (chi squ are = 10.539; p =0.10), and o pera tive a ppr oac h (chi squar e = 2.560; p =0.46). Ho wev er, a significant difference betw een the twogroups was found for the distribut ions of femoral headinjury (chi squar e = 9.554; p = 0.002), poste rior dislocation (chi square = 5.541; p = 0.02), initial displacement(chi square = 12.211; p = 0.007), and wound infection(chi squ are = 6.3689; p = 0.02). Th e significant differences occurred becau se 12 per cent mo re hips that hada femoral head injury were included in the study thanwer e lost to follow-up (fifty [19 per c ent] of 262, compare d w ith nine [7 per cent] of 124). Also , 12 per centmo re hips that had a posterior dislocation were includedin the study than were lost to follow-up (eighty-six [33per cent] of 262, com pared with twenty-six [21 per cent]of 124). Furth erm ore, 18 per cent more hips that hadbetween five and ten millimeters of initial displacementwere lost to follow-up than were included in the study(sixty-eight [55 per cent] of 124, com pare d w ith ninety-seven [37 per cent] of 262). Finally, all hips that had awound infection were included in the study and nonewere lost to follow-up.

DiscussionThe primary complication following a fracture ofthe acetabulum is post-t rau matic osteoarth rosis thatmay necessi tate a total hip replacement or an arthro-

VOL. 78-A, NO. 11, NOVEM BER 1996


11/14

1642 X M. MATTA

F I G . 2-AFigs. 2-A, 2-B, and 2-C: Radi ographs of a fifty-year-old man who had a posterio r column-poster ior wall fracture of the right acetabulum.Fig. 2-A: Anteroposterio r and 45-degree oblique radiographs showing the fracture.

F I G . 2-BAnteroposterior and 45-degree oblique radiographs made after open reduction and internal fixation with the Kocher-Langenbeckapproach, performed seven days after the injury. The reduction was graded as anatomical.

desis3'6'9-11-12-'5-IM"-22'23-25. Other possible sequelae include os- tremity secondary to bone deformity, defects, or wear1226,teonecrosis of the femoral head; acetabular non-union The goal of operative trea tment is to preserve a func-and bone defects; and shortening of the ipsilateral ex- tional, mobile, painless hip joint that continues to func-

THE JOURNAL OF BONE AND JOINT SURG ERY


12/14

FRACTURES OF THE ACETABULUM: ACCURACY OF REDUCTION AND CLINICAL RESULTS 1643

FIG. 2-CAnteroposterior radiograph made 8.5 years after the injury. The result was excellent clinically and radiographically, and motion of the hip

was normal. Full strength of the abductors did not return for four years. The very proximal fracture into the grea ter sciatic notch was judgedto have probably injured the superior gluteal nerve.tion for the rest of the patient 's life. Not all potentiallydeleterious effects of the initial injury can be completely countered in all patients. The success of the operat ion after high-energy trauma is contingent on thearticular cartilage of the hip remaining viable. If postt raumatic osteoarthrosis develops in the presence ofviable cartilage, it is primarily the result of altered pressure distribution of the femoral head articulating withan inaccurately reduced acetabulum. Specifically, thecontact area between the head of the femur and theacetabu lum is marke dly reduce d by a malredu ction, andthe force per uni t area to the art icular cart i lage increases. This results in loss of the joint space and, somet imes, in wear of the femoral head.

One goal of the current s tudy was to determinewhich factors associated with the injury could be usedto predict the p rognosis . Fracture type was not foundto be a significant predictor; in fact, the purpose ofthe classification system of Letournel and Judet12 wasanatomical descript ion and guidance of the operat iveapproach rather than prognosis . Of the subset of fourteen hips with a T-shaped posterior wall fracture, onlyeight had an excellent or good result, but this findingwas not s ignificant because of the small number ofthese fractures. Posterior dislocation at the time of theinjury, associated injuries, and the initial displacementof the fracture were not predictors of a worse prognosis, as previously reported26 . Also, as already noted,patients who were forty years old or more had significantly wor se clinical results (p = 0.02); how ever , thedifference is accounted for in the intermediate-resul t(good and fair) catego ry that is, the patien ts wh owere more than forty years old had fewer good and

more fair results, while the percentages of excellent andpoor results were almost identical for patients fortyyears old or less and those more than forty years old.Furthermore, when the factor of reduct ion is control ledfor, the differences between the two age-groups are nolonger significant, indicating that the result is more affected by redu ction tha n by age. Neithe r impac tion ofthe acetabular articular surface nor intra-articular freefragments, which indicate some degree of comminutionand addit ional problems in reconstruct ion, were predictive of the progn osis. Finally, the m ost clearly pred ictiveinitial factor was injury to the cartilage or bone, or both,of the femoral head; this factor was significantly predictive of a worse prognosis (p = 0.01).

Osteonecrosis of the femoral head, which is knownto result from the injury, can produce an unsatisfactoryclinical result regardless of the method of treatment;however, osteonecrosis occurred after only eight (3per cent) of the 262 fractures in the current study. Letournel and Judet12 reported osteonecrosis after nineteen (4 per cent) of 492 fractures. Subsequent wear ofthe femoral head against a malreduced acetabulum wasa more frequent problem and was seen in thirteen (5per cent) of the 262 hips in the current series. Higherrates of osteon ecrosis (thirtee n [23 per ce nt] of fifty-six hips) have been reported in other series 26 ; howev er,the wear may have been incorrect ly at t ributed to osteo nec rosi s (Figs. 1-A, 1-B, and 1-C).Another goal of the current s tudy was to assess therelat ionship between the qual i ty of the operat ive reduction (including any complications) and the clinicalresul t . When the resul ts of anatomical reduct ion werecompared with those of imperfect and poor reduct ions,

VOL. 78-A, NO. 11, NOVEMBER 1996


13/14

1644 J. M. MATTAthe forme r w as found to be a highly significant pre dictorof an excellent or good clinical result (chi square =9.910; p = 0.002). In earlier reports of the results inthe cur ren t series, with smaller num ber s of hips andshorter durat ions of fol low-up, anatomical and imperfect reductions were found to have similar outcomes1618 .In those reports , an anatomical reduct ion was definedas one that resulted in zero to one millimeter of displacement; an imperfect (satisfactory) reduction, as onethat resulted in two to three millimeters of displacement; and a poor (unsat isfactory) reduct ion, as one thatresul ted in more than three mil l imeters of displacement16 '8. The largest difference in the results was foundwhen those of anatomical and imperfect reduct ionswere grouped together and compared with those ofpoor reduct ion. With the greater number of pat ientsand the longer durat ion of fol low-up in the currentreport, the findings have changed. The results of anatomical reduction clearly differed from those of imperfect and poor reductions, a finding that supports that ofLetournel and Judet12 (Figs. 2-A, 2-B, and 2-C). Thesenew findings have led me to abandon the terms usedpreviously for reduction (anatomical, satisfactory, andunsatisfactory). The term satisfactory is particularly misleading because it implies that displacement of as muchas three mil l imeters is acceptable; al though this wassupported, to a certain degree, by the data reportedpreviously1618, i t is not supported by the current, morecomplete data.

Despite the appearance of an anatomical reduction on radiographs, there may still be imperfectionson areas of the articular surface that are invisible onstandard plain radiographs or are hidden by platesand screws. Eve n whe n the quality of the reduction isknown precisely, the al lowed one mil l imeter of displacement is not s t rict ly anatomical nor are the inevi table displacements that are too small to be seen,felt, or measured. I believe that these tiny displacements are always present , even with an anatomicalreduction. It follows that there are always alterationsin the distribution of pressure within the joint afteran acetabular fracture and i ts operat ive reconstruction. It must therefore be hypothesized that satisfactory clinical and radiographic results are due in partto the capability of the acetabulum in an adult to tolerate limited changes in the distribution of pressureand perhaps to reshape itself over time. However, ifa satisfactory long-term result is to be achieved, theterm anatomical reduct ion must be inherent in themindset of the operating surgeon, who must strive for

a reduct ion with no residual displacement .One of the main difficulties in the analysis of theseresults is the loss of almost one-third (124 of 386) ofthe hips to follow-up. Despite my continued efforts andthose of my research assistants , we were only partially successful because of the mobility (due to changesin residence and reasons related to occupation) of thisyoung-adul t American populat ion . The recourse wascomparison of the initial data for the 262 hips that hadad equ ate follow-up with those for the 124 hips that hadinadequate follow-up, in order to test the validity of thesample available for study.

Several factors indicate that the over-all rates ofexcellent and good clinical results would have beenslightly better if all patients had been available forfollow-up. Patients who had less than two years offollow-up and a clearly poor result were included, whilethose who had an excellent or good result but less thantwo years of follow-up were excluded. Significantlymore patients (p = 0.02) who had an associated injuryof the femoral head were available for follow-up. Allthirteen hips that had an infection were available forfollow-up. In addition, the series was skewed toward themore complex associated types of fractures, as most ofthe patients were not initially admitted to my institutionbut were referred later because of expected technicaldifficulty with the reduction and fixation. Therefore, thecurrent data probably represent an underest imation ofthe possibility of preserving the hip joint after a displaced acetabular fracture.

The strong relat ionship between the qual i ty of thereduction and the clinical result closely parallels thefindings of Letournel and Judet12 . It can theref ore beconcluded that the posi t ive resul ts reported by Letournel and Judet can be reproduced by the concentratedefforts of a surgeon who treats these fractures frequently and over an extended period of t ime. Otherauthors have reported poor resul ts for as many astwenty-four (43 per cen t) of fifty-six hips when multiplesurgeons with less experience and inconsistent protocols participated52 6. Thus, the indications for operativetreatment may not be the same in all clinical settings, asa pat ient who has had an operat ion that resul ted in apoor reduction or a serious complication can be worseoff than one who has had no operation at all. Management of patients at specialized centers where these injuries are treated frequently will probably yield the bestclinical re sults.

NOTE: The a utho r thank s Margare t del Valle. B.S. , for her help in the tabulation,description, and statistical analysis of the results.

References1. Fishmann, A. J.; Greeno, R. A.; Brooks, L. R.; an d Matta, J. M.: Prevention of deep vein thrombosis and pulmonary embolism inacetabular and pelvic fracture surgery. Clin. Orthop., 305:133-137,1994.2. Ghalambor, N.; Matta, J. ML; an d Bernstein, L.: Heterotopic ossif ication following operative treatment of acetabular fracture . Ananalysis of risk factors. Clin. Orthop., 305: 96-105,1994.3. John son, E. E.; Matta, J. M.; Mast, J. W.; an d Letournel, E.: Delayed re cons tructio n of acetabula r fractures 21-120 days following injury.Clin. Orthop., 305:20-30,1994.

T HE JOURN AL OF BONE AND JOIN T SURGE RY


14/14

FRACTURES OF THE ACETABULUM: ACCURACY OF REDUCTION AND CLINICAL RESULTS 16 454. Judet, R.; Judet, J.; an d Letournel, E.: Fract ures of the acetabu lum: classification and surgical appr oach es for open reductio n. J. Boneand Joint Surg., 46-A: 1615-1646, Dec. 1964.5. Kaempffe, F. A.; Bone, L. B.; an d Border, J. R.: Open reduction and internal fixation of acetabular fractures: heterotopic ossificationand other complications of treatment. J.Orthop. Trauma, 5: 439-445,1991.6. Kebaish, A.; Roy, A.; an d Rennie , W.: Displaced acetabular fractures: long-term follow-up.. /. Trauma, 31:1539-1542,1991.7. Knight, R. A., an d Smith, H.: Central fractures of the acetabulum. / . Bone and Joint Surg., 40-A: 1-16, Jan. 1958.8. Letournel, E.: Les fractures du cotyle, etu de d'u ne serie de 75 cas. / . chir, 82: 47-87,1961.9. Letournel, E.: The results of acetabu lar fractures treat ed surgically. 21 yea rs' experien ce. In The Hip. Proceedings of the Seventh OpenScientific Meeting of The Hip Society. St. Louis, C. V. Mosby, 1979.10 . Letournel, E.: Op en red ucti on and inte rnal fixation of aceta bular fract ures: long term re sults and analysis of 1040 cases [abstract ]. In 1s t

International Symposium on Surgical Treatment of Acetabular Fractures, p. 2. Paris, Fond ation de L'Avenir, 1993.11 . Letournel, E. : The treatment of acetabular fractures through the i l io inguinal approach. Clin. Orthop., 292:62-76,1993.12 . Letournel, E., an d Judet, R.: Fractures of the Acetabulum, edited by R. A. Elson. New York, Springer, 1993.13 . Levine, M. A.: A treatment of central fractures of the acetabulum. / Bone and Joint Surg., 25:902-906, Oct. 1943.14 . Matta, J.: Opera tive indications and choice of surgical approach for fractures of the acetabulum. Tech. Orthop., 1:13-22,1986.15 . Matta, J. M.: Operative treatment of acetabular fractures through the i l io inguinal approach. A 10-year perspective. Clin. Orthop., 305:10-19,1994.16 . Matta, J. M., an d Merritt, P. O.: Displaced acetabu lar fractures. Clin. Orthop., 230: 83-97,1988.17 . Matta, J. M.; Letournel, E.; an d Browner, B. D.: Surgical management of acetabular fractures. In Instructional Course Lectures, The

American A cademy of Orthopaedic Surgeons. Vol. 35, pp. 382-397. St. Louis, C. V. Mosby, 1986.18 . Matta, J. M.; Mehne, D. K.; an d Roofl, R.: Fractures of the acetabulum. Early results of a prospective study. Clin. Orthop., 205: 241-250,1986.19 . Matta, J. M.; Anderson, L. M.; Epstein, H. C; an d Hendricks, P.: Fractures of the acetabulum. A retrospective analysis . Clin. Orthop.,205:230-240,1986.20 . Mayo, K. A.: Open reduction and internal fixation of fractures of the acetabulum. Results in 163 fractures. Clin. Orthop., 305: 31-37,1994.21 . Merle d'Aubigne, R. M., an d Postel, M.: Functional results of hip arthroplasty with acrylic prosthesis. J. Bone and Joint Surg., 36-A:451-475, June 1954.22 . Oransky, M., an d Sanguinetti, C : Surgical treatm ent of displaced a cetab ular fracture s: results of 50 consecutive cases. / Orthop. Trauma,7:28-32,1993.23 . Pantazopo ulos, T., an d Mousafiris, C : Surgical treatment of central acetabular fractures. Clin. Orthop., 246: 57-64,1989.24 . Rom ness , D. W., an d Lewallen, D. G.: Total hip arthro plasty after fracture of the acetab ulum . Long- term resu lts. /. Bone and Joint Surg.,72-B(5): 761-764,1990.25 . Ruesch, P. D.; Holdener, H.; Ciaramitaro, M.; an d Mast, J. W.: A prospective study of surgically treated acetabular fractures. Clin.

Orthop., 305: 38-46,1994.26 . Wright, R.; Barrett, K.; Christie, M. J.; an d Johnson, K. D.: Acetabular fractures: long-term follow-up of open reduction and internal' fixation. J. Orthop. Trauma, 8: 397-403,1994.

VOL. 78-A, NO. 11, NOVEM BER 1996

Documents

Fractures of the Acetabulum Accuracy of Reduction and Clinical Results