Rotational acetabular osteotomy for advanced osteoarthritis secondary to developmental dysplasia of the hip

Effect of coronal plane acetabular correction on joint contact pressure in Periacetabular osteotomy: a finite-element analysis

Background

The ideal acetabular position for optimizing hip joint biomechanics in periacetabular osteotomy (PAO) remains unclear. We aimed to determine the relationship between acetabular correction in the coronal plane and joint contact pressure (CP) and identify morphological factors associated with residual abnormal CP after correction.

Methods

Using CT images from 44 patients with hip dysplasia, we performed three patterns of virtual PAOs on patient-specific 3D hip models; the acetabulum was rotated laterally to the lateral center-edge angles (LCEA) of 30°, 35°, and 40°. Finite-element analysis was used to calculate the CP of the acetabular cartilage during a single-leg stance.

Results

Coronal correction to the LCEA of 30° decreased the median maximum CP 0.5-fold compared to preoperatively (p <  0.001). Additional correction to the LCEA of 40° further decreased CP in 15 hips (34%) but conversely increased CP in 29 hips (66%). The increase in CP was associated with greater preoperative extrusion index (p = 0.030) and roundness index (p = 0.038). Overall, virtual PAO failed to normalize CP in 11 hips (25%), and a small anterior wall index (p = 0.049) and a large roundness index (p = 0.003) were associated with residual abnormal CP.

Conclusions

The degree of acetabular correction in the coronal plane where CP is minimized varied among patients. Coronal plane correction alone failed to normalize CP in 25% of patients in this study. In patients with an anterior acetabular deficiency (anterior wall index < 0.21) and an aspherical femoral head (roundness index > 53.2%), coronal plane correction alone may not normalize CP. Further studies are needed to clarify the effectiveness of multiplanar correction, including in the sagittal and axial planes, in optimizing the hip joint’s contact mechanics.

Ilizarov Technique with Proximal Femoral and Triple Pelvic Osteotomy for the Treatment of Adolescent Developmental Dysplasia of the Hip

Objective  The significance of pelvic osteotomies in developed coxarthrosis is still disputable. Some authors believe that incongruence and early osteoarthritis of the articular surfaces are contraindications for joint-preserving surgery and will stimulate further progression. The opposite view is that triple pelvic osteotomy can be an alternative to early joint replacement. The present study reports the mid to long term results of adolescent patients with developed coxarthrosis treated by proximal femoral and triple pelvic osteotomies and fixed by the Ilizarov technique.

Methods  A retrospective review between 2002 and 2014 of the treatment of 26 patients with coxarthrosis due to developmental dysplasia of the hip (DDH). The sample was composed of 22 female and 4 male subjects with a mean age at operation of 14.7 years (range: 12–18 years) and mean follow-up of 5.9 years (range: 3–13 years).

Results  The initial functional results according to the Merle d'Aubigné and Postel criteria were: pain – 4.3 ± 0.05 points; range of motion – 3.6 ± 0.3 points; and gait – 4 ± 0.15 points. The average index of the weight bearing zone (WBZ) was of 38.7° ± 2.721°. The acetabular coefficient (AC) was of 162 ± 6.8, the center–edge angle (CEA) of Wiberg was of 3° ± 0.2°. The outcomes were followed up from 3 to 13 years. At the final follow-up, the radiographic outcomes showed that the value of the WBZ decreased to 8.2° ± 1.293° (0–15°), and that the AC increased to 249 ± 12.05. The average neck–shaft angle (NSA) was of 115° ± 4°, the articulo-trochanteric distance (ATD) was of 8,5 ± 1,5 mm, and the CEA of Wiberg was of 28° ± 1.6°) at the final follow-up. The distribution of the joints according to Tönnis et al was: grade I – 17 joints; grade II – 8 joints; and grade III – 1 joint. The outcomes were good for 14 patients (54%), fair for 10 patients (34.5%), and poor for 2 (11.5%) patients.

Conclusion  The treatment of adolescent hip dysplasia requires a proper assessment of the degree of dysplasia and the surgery needed to redirect pelvic components to achieve suitable conditions for hip remodeling, and our mid- to long-term results showed very good outcomes when applying these principles using the Ilizarov technique.

Minimum 10-Year Clinical Outcomes After Periacetabular Osteotomy for Advanced Osteoarthritis Due to Hip Dysplasia

The purpose of this study was to examine the minimum 10-year clinical outcomes, including patient-reported and functional outcomes, of periacetabular osteotomy in patients with advanced osteoarthritis. A total of 46 hips in 44 patients with advanced osteoarthritis who underwent periacetabular osteotomy between 1992 and 2006 were retrospectively reviewed. Mean age at surgery was 47.5 years, and mean follow-up was 16.9±4.7 years. Survivorship was determined using the Kaplan-Meier method, and the associated risk factors for the endpoint-conversion to total hip arthroplasty less than 15 years after surgery-were evaluated. The Oxford Hip Score and the University of California, Los Angeles activity score were evaluated at final follow-up. The survival rates at 15 and 20 years after surgery were 80% and 59%, respectively. Multivariate analysis indicated that body mass index greater than 24 kg/m² (P=.034; odds ratio, 1.72) was significantly associated with the endpoint as an independent risk factor. For 32 hips of 31 patients with preserved native joints at final follow-up, the Oxford Hip Score and the University of California, Los Angeles score averaged 41±5 and 5.2±1.8, respectively, equivalent (P=.28 and P=.215, respectively) to the scores of 14 hips of 13 patients with conversion to total hip arthroplasty (38±8.7 and 5.8±1.4, respectively). The results of this mid-term study may be useful for surgical decision-making among patients with advanced osteoarthritis who want to preserve native hip joints. [Orthopedics. 2018; 41(5):300-305.].

Preoperative planning for redirective, periacetabular osteotomies

Redirective, periacetabular osteotomies (PAO) represent a group of surgical procedures for treatment of developmental dysplasia of the hip (DDH) in skeletally mature and immature patients. The ultimate goal of all procedures is to reduce symptoms, improve function and delay or prevent progression of osteoarthritis. During the last two decades, the understanding of the underlying pathomechanisms has continuously evolved. This is mainly attributable to the development of the femoroacetabular impingement concept that has increased the awareness of the underlying three-dimensional complexity associated with DDH. With increasing knowledge about the pathobiomechanics of dysplastic hips, diagnostic tools have improved allowing for sophisticated preoperative analyses of the morphological and pathobiomechanical features, and early recognition of degenerative changes, which may alter the long-term outcome. As redirective, PAO are technically demanding procedures, preoperative planning is crucial to avoid intraoperative obstacles and to sufficiently address the patient-specific deformity. Although conventional radiography has been used for decades, it has not lost its primary role in the diagnostic work-up of patients with DDH. Furthermore, an increasing number of modern imaging techniques exists allowing for assessment of early cartilage degeneration (biochemical magnetic resonance imaging) as well as 3D planning and computer-based virtual treatment simulation of PAO. This article reviews the literature with regard to the current concepts of imaging of DDH, preoperative planning and treatment recommendations for redirective, PAO.

Clinical Results and Prognostic Factors for Outcomes of Valgus Femoral Osteotomy Combined with Chiari Pelvic Osteotomy for Osteoarthritis of the Hip

Background

Surgeons have long debated whether advanced or end-stage osteoarthritis of the hip in young patients should be treated with total hip arthroplasty or osteotomy. We reviewed the intermediate-term clinical results of valgus femoral osteotomy combined with Chiari pelvic osteotomy (VCO) for advanced or end-stage osteoarthritis associated with severe acetabular dysplasia of the hip in young patients and analyzed prognostic factors related to conversion to total hip arthroplasty.

Methods

The study group included 54 hips in 50 patients (5 men and 45 women; average age at the time of surgery, 45.6 years). The minimum and average durations of follow-up were 10 and 17.6 years, respectively. The Japanese Orthopaedic Association hip score (JOA score) was used for clinical evaluation. The probability of survival of the VCO from the time of the operation until the end point of conversion to total hip arthroplasty was calculated with use of the Kaplan-Meier method. We defined prognostic factors of outcome (conversion to total hip arthroplasty) with the Cox proportional hazards model.

Results

The mean total JOA score increased from 53.0 points preoperatively to 77.1 points at 1 year postoperatively, 81.6 points at 5 years, and 76.8 points at 10 years. The survival rates were 83.3%, 59.7%, and 46.9% at 10, 15, and 20 years, respectively. On univariate and multivariate analyses, patients with a low degree of acetabular roof obliquity had better postoperative results.

Conclusions

VCO is a surgical approach that preserves joint function in young patients with advanced or end-stage osteoarthritis associated with severe acetabular dysplasia of the hip. The postoperative prognosis of VCO was improved in patients with a low degree of acetabular roof obliquity.

Level of Evidence

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Open treatment of dysplasia-other than PAO: does it have to be a PAO?

Hip dysplasia is a developmental disorder that results in anatomic abnormalities in which the acetabular coverage is insufficient. In the absence of severe degenerative changes, younger active patients with these symptomatic structural abnormalities are increasingly managed with joint-preserving operations. Historically there have been numerous reconstructive pelvic osteotomies. In recent years, the Bernese periacetabular osteotomy (PAO) has become the preferred osteotomy by many surgeons. Even so, as our understanding of the hip advances and new diagnostic and treatment techniques are developed, we sought to put a focus on the long-term results of augmental osteotomies and pelvic osteotomies other than the PAO, to see if any of these surgeries still have a place in the current algorithm of treatment for the dysplastic hip. As the longevity of the treatment is the focal point for joint preservation surgeries for the dysplastic hip, these authors have searched databases for articles in the English literature that reported results of long-term follow-up with a minimum of 11-year survivorship after surgical treatment of developmental dysplasia of the hip. Reconstruction osteotomies for the dysplastic hip are intended to restore normal hip anatomy and biomechanics, improve symptoms and prevent degenerative changes, in this manuscript each procedure is independently assessed on the ability to achieve these important characteristics.

Gender difference does not affect the outcomes of eccentric rotational acetabular osteotomy used in hip dysplasia

INTRODUCTION

Various types of periacetabular osteotomies have been proposed to treat acetabular dysplasia for young and active patients. Acetabular dysplasia is prevalent in women and rare in men, therefore few reports exist concerning periacetabular osteotomy of male patients. The purpose of this study is to clarify the gender differences in surgical techniques, radiographic and clinical outcomes.

MATERIALS AND METHODS

Between 1989 and 2007, we performed 530 eccentric rotational acetabular osteotomies and followed them annually for more than five years. Thirty-six male patients were investigated. As a control group, 72 female patients were matched for age and preoperative stage of osteoarthritis at the time of surgery. We evaluated operative time and blood loss, radiographic parameters, Harris Hip Score (HHS) and survival rate. We investigated the clinical and radiographic differences between men and women.

RESULTS

The mean operative time was 148 min in males and 135 min in females. The bleeding during surgery was 445 g in males and 351 g in females. HHS improved 94.1 points in males and 93.5 points in women postoperatively. The mean CE angle improved 31.7° in males and 35.1° in females. The mean AHI was 90.8% in males and 94.1% in females postoperatively. The survival rate of male patients were 92.8% and that of female patients were 98.1%.

CONCLUSIONS

The mean operative time and the blood loss were not significantly different between male and female patients. Postoperative CE angle tended to be smaller in male than female patients. The survival rate was not significantly different between males and females. Gender difference did not affect the clinical outcomes of ERAO in patients with hip dysplasia.

Relationship of acetabular dysplasia in females with osteoarthritis of the hip to the distance between both anterior superior iliac spines

BACKGROUND

Acetabular dysplasia (AD) is the main cause of hip osteoarthritis in Japan. A simple method to evaluate acetabular dysplasia would be helpful for early treatment or prevention of hip osteoarthritis. Acetabular dysplasia is reported to be associated with pathological transverse growth of the pelvis, indicating that the distance between the 2 anterior superior iliac spines might be useful for screening and detection of acetabular dysplasia. The purpose of this study was to determine if the acetabular dysplasia radiographic parameters are related to the distance between the 2 anterior superior iliac spines in patients with hip osteoarthritis.

MATERIAL AND METHODS

In this study, data obtained in a previous multi-institutional examination of patients with hip osteoarthritis in Japan were evaluated. The anterior superior iliac spine distances of 176 female patients (mean age, 54 years; range, 18-85 years) were measured by physical examination. The relationship between the anterior superior iliac spine distance and acetabular dysplasia was analyzed, and the anterior superior iliac spine distances of the patients with acetabular dysplasia who were at relatively high risk for hip osteoarthritis were compared with that of the patients at lower risk.

RESULTS

A statistically significant relationship between the anterior superior iliac spine distance and all of the acetabular dysplasia parameters was observed. The anterior superior iliac spine distances of the acetabular dysplasia patients with a relatively high risk for radiographic acetabular dysplasia parameters were significantly smaller than those of patients at lower risk. Even after adjustment for age, height, and weight, significantly increased relative risk for having high risk AD was found in patients with an ASIS distance of less than 24.5 cm.

CONCLUSIONS

There was a significant relationship between the anterior superior iliac spine distance and the degree of acetabular dysplasia.

Rotational acetabular osteotomy with resection of the capital drop and double floor for advanced osteoarthritis of the hip

Rotational acetabular osteotomy (RAO) is an established joint preservation technique for early stage osteoarthritis (OA). To extend the application of RAO for advanced OA with significant osteophyte formation, we added intraarticular procedures including removal of the double floor and the capital drop to create medialisation and better coverage of the femoral head.
The procedures were performed for seven joints with advanced OA. The average age of patients at surgery was 39 years. The follow-up periods ranged from five to 23 years. The capital drop was resected in five joints and both the capital drop and the double floor were removed in the other two joints.
The Japanese Orthopaedic Association Hip Score improved from 53 points before surgery to 69 at the latest follow-up. The range of flexion was decreased. The centre-edge angle, Sharp angle and acetabular head index were significantly improved. The femoral head was medialised 5 mm by surgery. Three joints (43%) showed progression of osteoarthritis. One joint (14%) needed replacement at seven years after RAO. Resection of the capital drop and curtain osteophyte with RAO improved joint congruity and medialisation of the femoral head, but decreased the range of motion of the joint due to increased bony coverage. Progression of degeneration of the joint is not preventable. We abandoned these procedures for advanced osteoarthritis of the hip joint especially in older patients who were suitable for replacement arthroplasty.

Rotational acetabular osteotomy through an Ollier lateral U approach for early-stage osteoarthritis secondary to acetabular dysplasia

OBJECTIVE

To explore the surgical technique and mid-term results of rotational acetabular osteotomy for early -stage osteoarthritis secondary to acetabular dysplasia.

METHODS

Rotational acetabular osteotomies were performed on 14 hips of 12 patients from May 2000 to May 2006 and the patients followed up. All patients were female and their average age was 28.9 years (range, 13-46 years) at the time of surgery. The mean duration of clinical and roentgenographic follow-up was 6.0 years (range, 3.1-9.1 years). The lateral center-edge (CE) angle, acetabular roof angle and head lateralization index were measured on radiographs taken preoperatively, postoperatively and at the time of final follow-up. Clinical follow-up included use of the Harris hip score. The acetabular osteotomies were performed through an Ollier lateral U transtrochanteric approach and postoperative traction and cast immobilization were not used.

RESULTS

All patients had satisfactory pain relief. The mean preoperative Harris score was 72 points; this had improved to a mean of 91 points at the time of last follow-up (P < 0.05). The mean CE angle improved from 0.9° preoperatively to 27° postoperatively (P < 0.05), the mean acetabular roof angle from 29° to 5° (P < 0.05) and the mean head lateralization index from 0.68 to 0.65. Solid bone-to-bone healing of the osteotomy sites and great trochanters occurred in all patients.

CONCLUSIONS

Rotational acetabular osteotomy through an Ollier lateral U approach, which provides wide exposure and technical ease, for early-stage osteoarthritis secondary to acetabular dysplasia can relieve pain and delay the appearance or reduce the severity of osteoarthritis. Satisfactory mid-term results can be obtained.

Patient selection criteria for periacetabular osteotomy or rotational acetabular osteotomy

BACKGROUND

Hip dysplasia is the most common cause of secondary osteoarthritis (OA). Periacetabular osteotomy (PAO) or rotational acetabular osteotomy (RAO) has been used as a joint-preserving procedure. However, the patient selection criteria are not clearly defined.

QUESTIONS/PURPOSES

Based on a systematic review, we identified reported patient selection criteria for PAO or RAO.

METHODS

We performed a systematic review of RAO and 18 studies met our inclusion criteria. For the PAO, the systemic review performed by Clohisy et al. was used. WHERE ARE WE NOW?: For patients with symptomatic hip dysplasia, lateral center-edge angle less than 10° to 30°, radiographic pre- or early OA, mean age at the time of surgery of 18 to 45 years, and improvement in joint congruency on AP radiograph with hip abduction, radiographic deformity correction consistently improved hip function in all studies. Radiographic OA progression was noted in 5% to 33% at 3.2 to 20 years postoperatively. Clinical score and prevention of radiographic OA progression of patients 50 years or older or with advanced stage were worse in younger patients or those with early stage. WHERE DO WE NEED TO GO?: The key challenges are (1) preoperative evaluation of articular cartilage; (2) indication for older patients; (3) prevention of secondary femoroacetabular impingement; and (4) intraarticular treatment combined with PAO or RAO. HOW DO WE GET THERE?: Future prospective, longitudinal cohort studies need to determine optimal patient selection criteria, risk factors for clinical failure, optimal deformity correction parameters, and the role of adjunctive surgical procedures.

The Chiari pelvic osteotomy for patients with dysplastic hips and poor joint congruency

We report the mid- to long-term (mean 20.3 years, 10 to 32.5) results of the Chiari pelvic osteotomy in patients with pre- to advanced stage osteoarthritis in dysplastic hips. We followed 163 Japanese patients (173 hips) with a mean age at surgery of 20 years (9 to 54). Overall, 124 hips (72%) had satisfactory results, with Harris hip scores ≥ 80. Satisfactory results were seen in 105 of 134 hips with pre- or early osteoarthritis (78%) and 19 of 39 hips with advanced osteoarthritis (49%). A total of 15 hips (9%) underwent a total hip replacement (THR) with a mean interval between osteotomy and THR of 16.4 years. With conversion to THR as the endpoint, the 30-year survival rate was 85.9% (95% confidence interval 82.3 to 89.5). It was 91.8% for patients with pre- or early osteoarthritis and 43.6% for those with advanced osteoarthritis (p < 0.001).

We now perform the Chiari osteotomy for patients with dysplastic hips showing poor joint congruency and who prefer a joint-conserving procedure to THR.

Peri-acetabular rotational osteotomy with concomitant hip arthroscopy for treatment of hip dysplasia

Reconstructive acetabular osteotomy is a well established and effective procedure in the treatment of acetabular dysplasia. However, the dysplasia is frequently accompanied by intra-articular pathology such as labral tears. We intended to determine whether a concomitant hip arthroscopy with peri-acetabular rotational osteotomy could identify and treat intra-articular pathology associated with dysplasia and thereby produce a favourable outcome. We prospectively evaluated 43 consecutive hips treated by combined arthroscopy and acetabular osteotomy. Intra-operative arthroscopic examination revealed labral lesions in 38 hips. At a mean follow-up of 74 months (60 to 97) the mean Harris hip score improved from 72.4 to 94.0 (p < 0.001), as did all the radiological parameters (p < 0.001). Complications included penetration of the joint by the osteotome in one patient, a fracture of the posterior column in another and deep-vein thrombosis in one further patient. This combined surgical treatment gave good results in the medium term.

We suggest that arthroscopy of the hip can be performed in conjunction with peri-acetabular osteotomy to provide good results in patients with symptomatic dysplasia of the hip, and the arthroscopic treatment of intra-articular pathology may alter the progression of osteoarthritis.

Treatment of experimental osteonecrosis of the hip in adult rabbits with a single local injection of recombinant human FGF-2 microspheres

Basic fibroblast growth factor (FGF-2) exerts anabolic actions on bone formation. Here we investigated the potential effects of recombinant human FGF-2 (rhFGF-2) on the repair process of osteonecrosis of the femoral head (ONFH) and the development of secondary osteoarthritis (OA) in adult rabbits. ONFH was induced by intramuscular injection with methylprednisolone, and vascular occlusion of the capital femoral epiphysis by electrocoagulation, in adult Japanese white rabbits. Animals were randomized into two groups: treatment and control. The treatment group was given a single local injection into the femoral head of 100 μg rhFGF-2 in 100 μl gelatin hydrogel microspheres 8 weeks after the ONFH procedure, and the control group was given phosphate-buffered saline in 100 μl gelatin hydrogel microspheres. Morphological, histopathological, and radiologic analyses, including micro-computed tomography scans and magnetic resonance imaging, showed collapse of the femoral head and progression of articular cartilage degeneration in the control group at 16 weeks after the single local injection of rhFGF-2. In contrast, rhFGF-2 treatment resulted in new bone formation in the femoral head and prevented the femoral head from collapsing. In addition, the changes in OA, assessed by the modified Mankin score, was significantly lower in the treatment group. Our results indicate that a single local injection of rhFGF-2 microspheres promoted the repair of the osteonecrotic femoral head and inhibited femoral head collapse and OA progression. rhFGF-2 may be a promising strategy for the treatment of ONFH.

Congenital hip disease in adults: terminology, classification, pre-operative planning and management

This paper reviews the current knowledge relating to the management of adult patients with congenital hip disease. Orthopaedic surgeons who treat these patients with a total hip replacement should be familiar with the arguments concerning its terminology, be able to recognise the different anatomical abnormalities and to undertake thorough pre-operative planning in order to replace the hip using an appropriate surgical technique and the correct implants and be able to anticipate the clinical outcome and the complications.

Periacetabular osteotomy reduces the dynamic instability of dysplastic hips

We compared the dynamic instability of 25 dysplastic hips in 25 patients using triaxial accelerometry before and one year after periacetabular osteotomy. We also evaluated the hips clinically using the Harris hip score and assessed acetabular orientation by radiography before surgery and after one year. The mean overall magnitude of acceleration was significantly reduced from 2.30 m/s(2) (sd 0.57) before operation to 1.55 m/s(2) (sd 0.31) afterwards. The mean Harris hip score improved from 78.08 (47 to 96) to 95.36 points (88 to 100). The radiographic parameters all showed significant improvements. This study suggests that periacetabular osteotomy provides pain relief, improves acetabular cover and reduces the dynamic instability in patients with dysplastic hips.

Rotational acetabular osteotomy for secondary osteoarthritis after surgery for developmental dysplasia of the hip

The treatment of residual deformity following surgery for developmental dysplasia of the hip remains controversial. The rationale for the use of the rotational acetabular osteotomy (RAO) is that it increases the weight-bearing area by shifting the osteotomized acetabulum to cover the femoral head. This can improve joint function as well as achieve relief of pain. However, it is unclear if this osteotomy can improve a compromised hip when performed for the treatment of residual deformity and acetabular dysplasia after surgery for developmental dysplasia of the hip. We aimed to report the clinical outcome as assessed by need for total hip arthroplasty (THA) and by the Merle d'Aubigné and Postel scores. In addition, we tried to assess the radiographic outcomes as assessed by Tönnis's classification. Only two hips required THA, which was performed in two patients at 11 and 12 years after RAO, respectively. The mean Merle d'Aubigné clinical score improved from 14.1 +/- 2.3 points (range, 10 to 17) preoperatively to 15.8 +/- 2.9 points (8 to 18) at final follow-up (p < 0.02). Radiological assessment at final follow-up showed the obvious progression of osteoarthritis in five hips. One patient in grade 1 preoperatively progressed into grade 3 at final follow-up; four patients in grade 2 preoperatively progressed into grade 3. In our study, this osteotomy prolonged the functional life of the hip, and only two hips needed THA after a mean follow-up of 11 years. We found that advanced arthritis pre-osteotomy is associated with progression of radiologic changes.

Comparison of periacetabular osteotomy and total hip replacement in the same patient

We evaluated 31 patients with bilateral dysplastic hips who had undergone periacetabular osteotomy for early (Tönnis grade 0 or 1) or moderate (Tönnis grade 2) osteoarthritis in one hip and total hip replacement for advanced (Tönnis grade 3) osteoarthritis in the other. At a mean follow-up of 5.5 years (2 to 9) after periacetabular osteotomy and 6.7 years (3 to 10) after total hip replacement, there was no difference in the functional outcome in hips undergoing osteotomy for early or moderate osteoarthritis and those with a total hip replacement, as determined by the Merle d’Aubigné and Postel score and the Western Ontario and McMaster Universities osteoarthritis index. More patients preferred the spherical periacetabular osteotomy to total hip replacement (53% vs 23%; p = 0.029). Osteoarthritis secondary to hip dysplasia is often progressive. Given the results, timely correction of dysplasia by periacetabular osteotomy should be considered whenever possible in young patients since this could produce a favourable outcome which is comparable with that of total hip replacement.

Joint congruency as an indication for rotational acetabular osteotomy

Long-term results of periacetabular osteotomy for advanced-stage osteoarthritis secondary to developmental dysplasia of the hip are reportedly unsatisfactory compared with results for early-stage osteoarthritis. Other preoperative information that can be used to determine indications for periacetabular osteotomy is therefore important to avoid performing osteotomy in young patients with advanced-stage osteoarthritis who would not likely achieve substantial benefit. We retrospectively reviewed 47 patients (49 hips) with advanced-stage osteoarthritis who underwent rotational acetabular osteotomy (RAO) using preoperative congruency in abduction. The minimum postoperative followup was 8 years (mean, 12.3 years; range, 8-20 years) and mean age at surgery was 43.1 years (range, 30-59 years). At followup, osteoarthritic stage was improved in 12 hips, unchanged in 24 hips, and had progressed in 13 hips. Preoperative joint congruency in abduction was good in 13 hips, poor in 32 hips, and narrowed in four hips. Patients with better congruency in abduction had better results. We believe osteoarthritis with good congruency in abduction preoperatively remains a good indication for RAO even in advanced stages of disease.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Rotational acetabular osteotomy for advanced osteoarthritis of the hip joint with acetabular dysplasia

Between August 1986 and July 1997, we performed rotational acetabular osteotomy (RAO) according to the methods of Ninomiya and Tagawa in 161 patients (179 hips). Among them, 63 patients (68 hips) had advanced osteoarthritis. We assessed the outcome at a mean of 12 years after rotational acetabular osteotomy was performed for the treatment of advanced osteoarthritis in a series of patients with acetabular dysplasia. Eleven patients did not return for final follow-up and were excluded from the study, leaving 52 patients (57 hips) for analysis. The mean Merle d'Aubigné clinical score improved from 12.6 points (range 9-16) preoperatively to 14.3 points (range 7-18) postoperatively (p < 0.002), mainly because of increased scores for pain. At final follow-up, 50 of the 57 hips were still functioning. The results of rotational acetabular osteotomy for correction of advanced osteoarthritis in adults with acetabular dysplasia were satisfactory after a mean of 12.2 years.