Rotational Acetabular Osteotomy for Advanced Osteoarthrosis Secondary to Dysplasia of the Hip

7/27/2019 Rotational Acetabular Osteotomy for Advanced Osteoarthrosis Secondary to Dysplasia of the Hip

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Abstract Clinical and radiological studies were done onthe results of rotational acetabular osteotomy for ad-vanced osteoarthrosis secondary to dysplasia of 29 adulthips followed up for 6 to 11 years postoperatively (mean8 years). Clinical evaluation by Merle dAubigne andPostels system showed improvement from a preoperativemean of 12.8 to a follow-up mean of 14.8, with aggrava-tion being observed in 8 joints. Radiologically, this proce-dure produced adequated improvement regarding femoralhead coverage, but improvement in joint congruencycould not necessarily be obtained due to joint deformityand progression of arthrosis, with aggravation of jointcongruency being observed in 6 joints. The most impor-tant factor influencing the postoperative results of thisprocedure was postoperative joint congruency. If the post-operative joint congruency is satisfactory, with the jointcongruent index being more than 6.0, progression ofarthrosis can be prevented in the long term by this proce-dure, even in advanced cases.

Introduction

For osteoarthrosis secondary to dysplasia of the hip, peri-

acetabular osteotomies to transfer the position of the ac-etabula en bloc, such as Steels triple osteotomy [12, 13],Wagners spherical acetabular osteotomy [15], Epprightsdial osteotomy [3] and Tagawas rotational acetabular os-teotomy (RAO) [11], are theoretically superior to the con-ventional acetabuloplasties and pelvic osteotomy such asChiaris osteotomy [2] from the standpoint that thefemoral head can be covered with articular cartilage. Sat-isfactory results of this procedure have been reported forearly stage osteoarthrosis secondary to dysplasia of thehip, and the usefulness of this procedure has also beenshown in long-term results [5, 14]. However, only a fewdetailed reports have been made on the results of this pro-

cedure for advanced cases, and the long-term results havebeen obscure [5, 17]. In the present study, RAO was per-formed for advanced cases, and 29 joints were reviewed611 years postoperatively (mean 8 years and 1 month),including the indications for advanced cases.

Patients and methods

The 29 patients of this study suffer from advanced osteoarthrosissecondary to dysplasia of the hip and underwent RAO between1986 and 1991. Osteoarthrosis of the hip was staged fromprearthrosis to end stage arthrosis according to the radiological ap-pearance. Prearthrosis presented no osteoarthrotic change from ac-

etabular dysplasia, early stage arthrosis was characterised by slightnarrowing of the joint space associated with sclerosis of the sub-chondral bone, advanced stage arthrosis by marked narrowing ofthe joint space with some cystic lucencies and small osteophytes inthe femoral head and acetabulum, and end-stage arthrosis by dis-appearance of the joint space with marked osteophytes.

All patients were women except for one. Their age at the timeof operation ranged from 21 to 56 years, with a mean of 39 yearsand 6 months. The postoperative follow-up period ranged from6 years to 11 years, with a mean of 8 years and 1 month. Accord-ing to Charnleys category classification [1], there were 12 unilat-eral cases (A) and 17 bilateral cases (B). The stages of the non-op-erated side of patients belonging to category B were prearthrosis in4 joints, early stage arthrosis in 9 joints, and advanced stage

Y. Yasunaga H. Iwamori Y. Ikuta S. Yamamoto A. Harada

Rotational acetabular osteotomy

for advanced osteoarthrosis secondary to dysplasia of the hip

Results at 611 years postoperatively*

Arch Orthop Trauma Surg (1999) 119 : 253257 Springer-Verlag 1999

Received: 16 July 1998

ORIGINAL ARTICLE

*No benefits in any form have been received or will be receivedfrom a commercial party related directly or indirectly to the sub-ject of this article.

Y. Yasunaga () Y. IkutaDepartment of Orthopaedic Surgery,

Hiroshima University School of Medicine, 1-2-3 Kasumi,Minami-ku, Hiroshima 734-8551, JapanTel.: (+81)82-257-5233, Fax: (+81)82-257-5234

H. IwamoriDepartment of Orthopaedic Surgery, Chuden Hospital,Hiroshima, Japan

S. YamamotoDepartment of Orthopaedic Surgery,Matsuyama Red Cross Hospital, Matsuyama, Japan

A. HaradaDepartment of Orthopaedic Surgery, Yoshida General Hospital,Hiroshima-ken, Japan


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arthrosis in 4 joints. As an additional procedure, valgus osteotomywas performed on 2 joints.

Cases showing improvement in femoral head coverage andjoint congruency in abduction on anteroposterior view of plainX-ray and arthrography were as a rule considered indications forthe operative procedure.

For the clinical assessment, we used the system of MerledAubigne and Postel [8] graded from 0 to 6 relief of pain, restora-tion of mobility and improvement in walking.

Radiological indices included CE angle [16], acetabular roofobliquity [7] and head lateralisation index [4], which was calcu-

lated from two lengths, from the centre of the femoral head to thetip of the teardrop and between bilateral teardrops (Fig.1). The dif-ference in the radius of curvature between the femoral head and ac-etabulum was regarded as the joint space (mm). From this valuewe subtracted the deviation (mm) of the femoral head centre andacetabulum centre, and 5 was added to obtain the joint congruentindex [6]. This index was employed in evaluating joint congruency(Fig.2).

Operative technique

RAO procedure [11] reported by Ninomiya and Tagawa was em-ployed, but for immobilization of the rotated acetabulum followingosteotomy, a sapphier screw (Kyocera, Kyoto, Japan) was used in-stead of Kirschner wire. None of the patients underwent limbus re-section or osteophyte resection. Range of motion (ROM) exercises

of the hip joint commenced 7 days postoperatively, followed fromthe 6th postoperative week by partial weight-bearing. Full weight-bearing was initiated 56 months postoperatively.

Results

Clinical evaluation showed a significant improvement fromthe preoperative mean of 12.8 1.4, with pain 3.0 0.7,mobility 5.0 0.5, and walking 4.8 0.5 to follow-upmean of 14.8 2.6, with pain 5.2 1.3, mobility 4.8 1.0, and walking 4.8 1.0 (Wilcoxon signed-rank test:P < 0.001). Improvement in pain grade was good, but thatof mobility decreased. In 19 joints, functional gradingshowed a score of 15 or more at the time of follow-up toaccount for 66% of the total (Table 1). Aggravation com-pared with the preoperative score was observed in 8 joints,and in one joint total hip arthroplasty (THA) was per-formed in the 5th postoperative year. Category compari-son of the clinical score did not demonstrate any signifi-cant difference; the aggravation cases concerned 3 jointsin group A and 5 joints in group B.

Radiologically, the CE angle showed significant im-provement from a preoperative mean of 4.2 to a postop-erative mean of 33, and the acetabular roof obliquityfrom a preoperative mean of 31 to a postoperative mean

of 5.4, with no case of aggravation. The head lateraliza-tion index improved from a preoperative mean of 0.70 toa postoperative mean of 0.67, but the difference was notsignificant (Table 2).

Joint congruent index changed from a mean preopera-tive value of 3.7 to mean 3-month value of 5.5 and tomean follow-up value of 5.3. The follow-up joint congru-ent index was aggravated compared with the preoperativevalue in 6 joints. Narrowing of the lateral joint space wasthe cause of the decrease in joint congruent index withprogression of osteoarthrosis and aggravation of the clini-cal score compared with the preoperative score. In the pa-tients showing improvement, no change or aggravation injoint congruent index at the time of follow-up comparedwith the preoperative stage, significant differences in jointcongruent index were observed 3 months postoperativelyand at follow-up. Of 23 joints in the non-aggravationgroup, 11 with a joint congruent index of more than 6.0observed 3 months postoperatively either maintained thisvalue or showed improvement (Table 3).

The factors found to be correlated to the clinical eval-uation at the time of follow-up were joint congruent index

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Fig.1 Radiological indices ofthe hip: = CE angle, = ac-etabular roof obliquity, head

lateralisation index = A1/2 T

Fig.2 Joint congruent index =(b a) d+ 5 (a radius of cur-vature in femoral head, b ra-dius of curvature in acetabu-lum, ddeviation of femoralhead centre and acetabulumcentre)

Table 1 Clinical score of 29 patients before and after rotationalacetabular osteotomy (RAO, THA total hip arthroplasty)

Score Preoperative Follow-up

Excellent (18) 0 5

Good (1517) 6 14

(Fair 1214) 18 6

Poor (< 12 or THA) 5 4

Table 2 Radiological evaluation in 29 patients before and 3months after RAO

Preoperative Postoperative

Centre-edge angle 4.2 9.0 33 9.0**(range) (22 to 10) (20 to 50)

Acetabular roof 31 8.8 5.4 10*obliquity (range) (12 to 47) (6 to 30)

Head lateralisation 0.70 0.08 0.67 0.11index (range) (0.59 to 0.91) (0.51 to 0.89)

*P < 0.01, ** P < 0.001, preoperative vs postoperative value,Wilcoxon signed-rank test


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Table 3 Joint congruent indexvalues

*P < 0.05, ** P < 0.001, Mann-Whitney U-test

Preoperative 3 months postoperative Follow-up

Total 3.7 1.4 5.5 1.5 5.3 2.0(29 joints)

Joints showing improvement 3.7 1.6 5.7 1.6 6.0 1.5or no change at follow-upcompared with preoperative > 6.0 (11 joints)index (n = 23) 7.0 0.9 7.5 0.4

***

****

< 5.9 (12 joints)4.4 0.9 4.7 0.8

Joints showing aggravation 4.0 1.1 4.5 0.6 2.4 0.4at follow-up compared withpreoperative index (n = 6)

3a b c

4a b c

5a b c

Fig.3ac A 50-year-oldwoman belonging to categoryB. Clinical score improvedfrom preoperative 11 (pain: 2,mobility: 5, walking: 4) to fol-low-up of 17 (pain: 6, mobil-ity: 6, walking: 5) at 9 yearsand 1 month postoperatively.Joint congruent index was

5 preoperatively (a), 6.5 at3 months postoperatively (b),and 7 at follow-up (c). Nochange in the non-operatedside was observed at the earlystage

Fig.4ac A 21-year-oldwoman belonging to categoryB. At the age of 13 years, sheunderwent varus osteotomy.RAO was performed togetherwith valgus osteotomy of thefemur. Clinical score improvedfrom preoperative 14 (pain: 4,mobility: 5, walking: 5) to fol-

low-up of 16 (pain: 6, mobil-ity: 5, walking: 5) at 8 yearspostoperatively. Joint congru-ent index improved from 5 pre-operatively (a) to 6.5 postoper-atively (b), and to 7.5 follow-ing remodeling (c). No changein the non-operated side wasobserved at prearthrosis

Fig.5ac A 31-year-oldwoman belonging to categoryB. Clinical score aggravatedfrom preoperative 13 (pain: 3,mobility: 5, walking: 5) to fol-low-up of 10 (pain: 4, mobil-ity: 2, walking: 4) at 9 years

and 6 months postoperatively.Joint congruent index im-proved from preoperative 3.0(a) to postoperative 4.5 (b), butdecreased to 2.0 at follow-up(c)


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at the time of follow-up (R = 0.740, P < 0.0001), postop-erative follow-up period (R = 0.597, P < 0.001) and jointcongruent index 3 months postoperatively (R = 0.497, P

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Rotational Acetabular Osteotomy for Advanced Osteoarthrosis Secondary to Dysplasia of the Hip