Use of iliofemoral distraction in reducing high congenital dislocation of the hip before total hip arthroplasty

The Journal of Arthroplasty Vol. 11 No. 5 1996

Use of Iliofemoral Distraction in Reducing High Congenital Dislocation of the Hip Before Total Hip Arthroplasty Kuo-An

Lai, M D , * J a i n L i u , M D , * a n d T a n g - K u e L i u , M D , D M S c J -

Abstract: The iliofemoral distraction with Wagner's apparatus was conducted in 20

adult patients with untreated unilateral congenital dislocation of the hip (Crowe group IV) before total.hip :arthroplasty. During the distraction period of 8 to 17 days, this technique had effectively reduced high dislocation~ob!4,~.~5-.cm(range, 3.5-5 cm). No pin-tract infection was encountered. Surgical difficulties in total hip arthroplasty for these patients were reduced. Potential problems, such as irreducibility, overshortening, nerve palsy, and displaced femoral fractures, were avoided. At an average follow-up period of 43 months (range, 25-63 months), all patients have excellent or good results, with an average Harris hip score of 94.3 (range, 84-100). Leg length was restored. The iliofemoral distraction is valuable prior to difficult total hip arthroplasty for high dislocation. Key words: congenital dislocation of hip, iliofemoral distraction, total hip arthroplasty, leg-length discrepancy, sciatic neuropathy.

Total hip arthroplasty (THA) is an acceptable t r e a t m e n t for painful, neglected congenital dislocation of the hip (CDH) in adult patients. High displacement of the femoral h e a d relative to the acetabulum is frequently e n c o u n t e r e d in these patients. A previous report indicates that longterm stability of the prosthesis with better abductor function and leg-length equalization is best achieved by placing the artificial joint near the normal anatomic level [1]. This is difficult, however, to achieve in patients with high dislocations w i t h o u t generous soft tissue releases and shortening ol the proximal femur, which m a y result in

muscle weakness and significant leg-length discrepancy. The efficacy of preoperative skeletal traction with or w i t h o u t soft tissue releases is rarely discussed. Grill first reported six children with high CDH treated with soft tissue releases and the use of an external fixator for distraction before open reduction that avoided excessive shortening [2]. To reduce surgical difficulties and complications of THA, we applied Wagner's distraction apparatus b e t w e e n the ilium and f e m u r in 20 consecutive patients with unilateral, untreated, high CDH before THA.

Materials and Methods From the *Department of Orthopedics, National Cheng Kung University Medical Center, Tainan, and ~-Department of Orthopedics, National Taiwan University Medical Center, Taipei, Taiwan, Republic of China.

From 1988 to 1991, 20 adult patients with unilateral, neglected CDH with proximal displacement of the f e m u r greater t h a n 4 cm were treated with iliofemoral distraction before THA (Table 1). Seve n t e e n patients were w o m e n and three were men. Ages ranged from 24 to 51 years (average, 35.6 years). Twelve patients had involvement of the

No benefit in any form has been received or will be received from a commercial party related directly or indirectly to the subject of this article. Reprint requests: Kuo-An Lai, MD, Department of Orthopedics National Cheng K u n g University Medical Center, 138, Sheng-Li Road, Tainan, Taiwan, R.O.C.

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Table 1. Details of 20 Patients With Untreated High Congenital Dislocation of the Hip Treated With Iliofemoral

Distraction and Cementless THA Case No.

Sex

Age (years)

Side

Preoperative LLD (cm)

Gain by IFD (cm)

Gain After THA (cm)

1 2 3 4

F M F F

29 26 34 29

R R R L

5.0 4.0 6.0 5.0

4.5 3.5 5.0 4.5

4.5 4.0 5.0 5.0

5 6 7 8 9 10 ll 12 13 14 15 16 17 18 19 20

F F F E M F F F F F F M F E F F

44 34 37 28 38 39 41 36 51 43 24 28 31 46 48 26

L R R L R L R R L R L R R L L R

5.0 5.0 6.0 5.0 6.0 5.0 5.0 4.0 5.0 5.0 6.0 6.0 4.0 4.0 5.0 4.0

4.0 4.5 5.0 4.5 5.0 4.0 5.0 4.0 5.0 4.5 5.0 5.0 4.0 4.0 4.5 4.0

4.5 4.5 5.0 5.0 5.0 4.5 5.0 4.0 5.0 5.0 5.5 5.5 4.0 4.0 5.0 4.0

Complication

Follow-up Period (months)

Hip Score

Grade

63 62 60 54

100 95 100 84

Excellent Excellent Excellent Good

54 53 47 46 42 41 40 40 38 37 33 31 3I 30 28 25

94 97 98 91 92 100 93 93 90 i00 91 92 97 96 94 90

Excellent Excellent Excellent Excellent Excellent Excellent Excellent Excellent Excellent Excellent Excellent Excellent Excellent Excellent Excellent Excellent

---Poor cup anchorage Fissure --Fissure Fissure -Fissure ---Fissure ------

LED, l e g - l e n g t h d i s c r e p a n c y ; IFD, i l i o f e m o r a l d i s t r a c t i o n .

right hip and eight had involvement of the left. Scanograms were taken with patients in the supine position to measure leg length for preoperative and postoperative follow-up evaluations. Leg length was measured on both sides as the vertical distance from the highest point of the iliac crest to the knee joint line. Preoperative leg-length discrepancies ranged from 4.0 to 6.0 cm (average, 5.0 cm). Preoperative Harris hip scores ranged from 56 to 75 (average, 68.2).

Procedure of Iliofemoral Distraction The procedures were carried out in the operating room with patients under anesthesia. In 12 patients with adduction contracture, subcutaneous adductor tenotomy was done first. In every patient, two or three Schantz screws were inserted percutaneously between both cortices of the iliac crest (intercortical insertion) in parallel fashion. With the leg at neutral position, two Schantz screws were also inserted percutaneously into the supracondylar region of the femur parallel to the screws in the iliac crest. Wagner's apparatus was assembled for distraction (Fig. 1). Initial distraction of 1 to 2 cm was done on the first day; thereafter, 2 m m of distraction divided by four times per day was done during the distraction period. Vital signs and neurovascular functions of the limb were closely monitored during the distraction period. Patients were allowed limited ambulation with

crutches during this period. Pin-tract care was instituted to prevent infection. When a desired length was achieved on the follow-up radiograph, the Wagner device was removed prior to skin preparation for THA.

Total Hip Arthroplasty Total hip arthroplasty was carried out through a transtrochanteric approach in 12 patients with overgrowth of the greater trochanter. The Hardinge lateral approach was used in six patients and the pos~erolateral approach was used in two patients with relatively normal proximal femora. The capsule was opened. The femoral head was excised and the joint capsule was then completely removed. The iliac bone over the true acetabulum was denuded for placing bone-graft. Because of preoperative distraction, Hohman retractors were easily placed anterior, posterior, and inferior to the true acetabulum, and the true acetabulum was well exposed. Deepening of the true acetabulum without perforation of the inner cortex was done for accommodation of the acetabular component. If the acetabulum appeared too shallow to cover completely the acetabular component after the initial reaming, bone-grafting was performed with the autogenous femoral head for augmentation. The acetabular defect was usually located at the roof or the anterosuperior wall, and adequate roof coverage was achieved by both grafting and the

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Fig. 1. Procedure of iliofemoral distraction: (a) Percutaneous adductor tenotomy is done in cases with adduction contracture. (b) Two or three screws are inserted percutaneously into the iliac crest (intercortical) at least 6 cm deep. (c) Two Schantz screws are inserted, also percutaneously, into the supracondylar region parallel to the previous screws. (d) Wagner's apparatus is assembled for gradual distraction.

(d)

proper selection of cup size. These grafts w e r e secured with screws before further reaming. Femoral h e a d grafting was required in I8 patients. A cementless, press-fit, hemispherical acetabular c o m p o n e n t (Dual Radius, Osteonics, Allendale, N J) was t h e n applied w i t h s u p p l e m e n t a r y screw fixation. A press-fit femoral stem (Omnifit, Osteonics) was inserted. In cases of femoral fracture, cerclage wires were applied. Iliopsoas t e n o t o m y was done in six patients with flexion contracture after trial reduction. Trochanteric o s t e o t o m y was also fixed with wires.

Postoperative Care Patients w e r e allowed to leave the bed as early as the third postoperative day. N o n - w e i g h t - b e a r i n g a m b u l a t i o n with crutches was encouraged. Full weight bearing was allowed 3 m o n t h s after surgery. Muscle-strengthening exercises a n d gait training w e r e instructed w h e n necessary. Harris hip scores were recorded during the follow-up period.

Results The distraction period varied f r o m 8 to I7 days, and 3.5 to 5.0 c m (average, 4.5 cm) of distraction was gained. No Schantz screw loosening, pin-tract infection, or n e u r o v a s c u l a r complications w e r e observed. The average operative time for THA was

106 m i n u t e s (range, 55-160 minutes). Blood loss averaged 786 mL (range, 400-1,400 mL). No femoral shortening o s t e o t o m y was required in a n y patient. Fissure of the p r o x i m a l f e m u r occurred in five patients. There w e r e no displaced fractures. Four to 5.5 cm (average, 4.7 cm) of lengthening was gained after THA w i t h o u t n e u r o v a s c u l a r complications. One patient h a d early acetabular comp o n e n t revision due to p o o r a n c h o r a g e and had a good final result. At an average follow-up period of 43 m o n t h s (range, 25-63 m o n t h s ) , Harris hip scores averaged 94.3 (range, 8 4 - i 0 0 ) . Nineteen patients h a d excellent a n d one h a d a good result. Thirteen patients w e r e pain-free and seven h a d only mild pain. Sixteen patients h a d no limp a n d the r e m a i n i n g four h a d a mild limp. No assistive devices w e r e required for walking. Walking distance was u n limited in 17 patients and mildly limited, but over 100 m, in the r e m a i n i n g 3. Sixteen patients h a d m o r e t h a n 90 ° flexion a n d the r e m a i n i n g four h a d 60 ° to 90 ° flexion. Range of abduction was over 15 ° in 18 patients and 10 ° to I5 ° in the r e m a i n i n g 2. Only two patients s h o w e d a mild Trendelenburg sign. There w e r e n o postoperative prosthetic dislocations. Femoral c o m p o n e n t subsidence was observed in six patients, but w e r e all less t h a n 2 ram. There was no evidence of loosening. No patient h a d a final leg-length discrepancy greater t h a n 2 cm. A typical case is illustrated in Figure 2.

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Fig. 2. (A) A 39-year-old woman with untreated congenital dislocation of the left hip had 5.0 cm of leg-length discrepancy before surgery. (B) Four centimeters was gained by using distraction for 14 days. (C) Cementless THA was done with bone-graft augmenting the roof. Leg length was nearly equalized without complication. The functional result was excellent 41 months after surgery.

Discussion The earliest report of THA in patients was discouraging [3]; however, with u n d e r s t a n d i n g of the m o r b i d a n a t o m y , surgical technique, as well as special designs, m o r e recent reports h a v e led to

w i t h CDH increased improved prosthetic the accep-

tance of THA for the s y m p t o m a t i c adult with CDH [4-8]. Nonetheless, THA for neglected CDH in Crowe group IV [9] or high dislocation by Hartofilakidis classification [5] r e m a i n s challenging. The p r i m a r y difficulties arise f r o m the deficient acetabulum, p o o r femoral b o n e stock, and contracted soft tissues a c c o m p a n y i n g the high dislocation. A suc-

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cessful THA depends on stable fixation of the components and on soft tissue balance. Most previous reports focused on reconstruction of the acetabulum and the proximal femur. Harris et al. reported reconstruction of the acetabulum with autogenous femoral head for bone-graft [1]. D u n n and Hess reported deepening of the acetabulum and fenestration of the medial wall and bone-graft [10]. Paavilainen et al. reported reconstruction of the proximal t e m u r [8]. Woolson and Harris [11] and Huo et al. [7] even designed special prostheses for patients with CDH. Few reports discuss the problems of soft tissue release and limb-length equalization. Harley and Wilkinson reported a technique to bring d o w n the hip with soft tissue releases from the iliac bone [12]. Even fewer reports discuss preoperative reduction of the high dislocation. Grill was the first to describe the application of distraction b e t w e e n the ilium and f e m u r before open reduction for CDH in children [2]. After releasing the adductor, flexor, and abductor, distraction was started with the Wagner's apparatus at a rate of 2 m m per day for 3 to 5 weeks. In Taiwan, there are still m a n y adults with CDH w h o go untreated. In an earlier series, before using iliofemoral distraction, we reported 11 cases of adults with neglected CDH treated with cementless THA b e t w e e n 1985 and 1988 [13]. All were unilaterally involved and had leg-length discrepancies greater t h a n 4.0 cm (range, 4.0-7.0 cm; mean, 5.1 cm). Eight patients received a one-stage operation (with or w i t h o u t skeletal traction), and three patients had a two-stage operation after soft tissue release. The distance that the femoral head could be pulled d o w n by skeletal traction was limited. Extensive release of the adductor, flexor, and abductor muscles, either before or at the time of THA, was itself a major surgery that w e a k e n e d the muscles, resulting in p o o r function. Therefore, the operative time was longer (range, 110-390 minutes; mean, 239 minutes) and the blood loss greater (range, 900-2,500 mL; mean, 1,371 mL) than in this study. Femoral s h o r t e n i n g osteotomy was p e r f o r m e d in four cases because of difficulties in hip reduction and all resulted in leg-length discrepancies of more t h a n 2 cm in addition to limping. Two patients had more t h a n 3.5 cm of shortening on the operative side. Serious complications were e n c o u n t e r e d m o r e frequently (7 of 11 cases). Besides excessive shortening, other complications included two displaced f e m u r fractures, one dislocation, one sciatic nerve palsy, and one acetabular c o m p o n e n t dislodgment (Table 2). Since 1988, we have applied iliofemoral distraction for patients with high displacement of the

Table 2. Comparison Between Groups of Patients With Untreated Congenital Dislocation of the Hip With and Without Iliofemoral Distraction Before THA Group With IFD Case (n) Age (years) Follow-up period (months) Preoperative LED (cm) Gain after THA

(cm) Operative time (minutes) Blood loss (mL) Hip score Major complications

20 35.6 (24--51) 43.0 (25-63)

Group Without IFD

P

11 25.5 (19-31) 46.0 (36-80)

5,0 _+0.7

5.1 +_ 1.0

.575 (NS)*

4.7 _+0.5

3.8 _+ 1.2

.03*

106 ± 29

239 _+74

.0001*

786 ± 268 94.3 +_4.2 1

1371 ± 456 85.2 + 8.1 7

.002* .004* .0001j-

*Student's t-test; tchi-square test. Ranges given in parentheses. IFD, iliotemoral distraction; LLD, leg-length discrepancy; NS, not significant.

femur before THA. The rationales are: (1) a more effective countertraction is applied across the hip joint; (2) it is a simple d o s e d surgery with little risk and few complications; (3) gradual distraction is safe; and (4) weakening of the muscle function is less. Also, initial distraction of I to 2 cm is safe, shortens the distraction period, and m a y reduce the chance of pin-tract infection. Two or three iliac pins are driven intercortically into the iliac crest as deep as possible to prevent loosening with distraction {14]. Two femoral pins are inserted into the supracondylar region instead of the proximal femur to avoid interference with the THA procedure. Nearly all previous reports have s h o w n high complication rates for THA in patients with CDH. C o m m o n complications include irreducibility, overshortening, nerve palsy, displaced fractures, dislocation, poor anchorage of implants, and limping. These complications were very c o m m o n in our earlier experiences w i t h o u t preoperative distraction; however, most of these complications were avoided in this series due to the use of iliofemoral distraction. We f o u n d it relatively technically easy to perform THA in patients with high. displacement of the f e m u r after iliofemoral distraction. The laxity after distraction and d o s e - t o - n o r m a l position of the f e m u r to the acetabulum made THA m u c h easier t h a n in those performed w i t h o u t distraction. The surgeons could concentrate more readily on acetabular and femoral reconstruction. Operative time, blood loss, and surgical complications were thus reduced, and the functional results are as good as those of ordinary THAs.

Iliofemoral Distraction Prior toTHA for CDH

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done with cement for severe dysplasia of the hip. J Bone Joint Surg 75A:1497, 1993 Paavilainen T, Hoikka V, Solonen KA: Cementless total hip replacement for severely dysplastic or dislocated hips. J Bone Joint Surg 72B:205, 1990 Crowe JE Mani VJ, Ranawat CS: Total hip replacement in congenital dislocation and dysplasia of the hip. J Bone Joint Surg 61A:15, 1979 Dunn HK, Hess WE: Total hip reconstruction in chronically dislocated hips. J Bone Joint Surg 58A: 838, 1976 Woolson ST, Harris WH: Complex total hip replacem e n t for dysplastic or hypoplastic hips using miniature or microminiature components. J Bone Joint Surg 65A:1099, 1983 Harley JM, Wilkinson JA: Hip replacement for adults with unreduced congenital dislocation: a n e w surgical technique. J Bone Joint Surg 69B:752, 1987 Lai KA, Liu TK, Yang CY, Lin CJ: Ileofemoral distraction for candidates of total hip arthroplasty with highly displaced femur. Trans AAOS 59:331, i992 Liu J, Lai KA, Chou YL: Strength of the pin-bone interface of external fixation pins in the iliac crest: a biomechanical study. Clin Orthop 310:237, 1995