Factors which affect the progression of osteoarthritis after rotational acetabular osteotomy

Analysis of survivorship following periacetabular osteotomy for hip dysplasia based on three-dimensional acetabular coverage

Periacetabular osteotomy (PAO) is an established procedure for correcting acetabular coverage and preventing osteoarthritis progression in hip dysplasia. However, it is unclear how acetabular coverage changes three-dimensionally after PAO and how it affects survival. Therefore, this study aimed to investigate the change in three-dimensional acetabular coverage preoperatively and postoperatively and identify demographic, clinical and radiographic factors associated with conversion to total hip arthroplasty (THA) and radiographic osteoarthritis progression after PAO. We retrospectively reviewed 46 consecutive patients (66 hips) who underwent PAO, using preoperative and postoperative radiographs and pelvic computed tomography (CT). Three-dimensional acetabular coverage based on CT data was investigated. Kaplan-Meier survival analysis was performed, and hazard ratios were calculated using univariate Cox regression models to identify the risk factors associated with conversion to THA and radiographic osteoarthritis progression after PAO as the endpoints. Radiographic osteoarthritis progression was defined as a minimum joint space of <2.0 mm. The mean follow-up was 10.7 years. Post-PAO, acetabular coverage gradually increased from the anterosuperior to the superior to the posterosuperior direction. The survival rate after PAO was 98.0% at 10 years. Less postoperative superior acetabular coverage, with a hazard ratio of 0.93, was significantly associated with conversion to THA and radiographic osteoarthritis progression after PAO (P = 0.03). In this study, poor superior acetabular coverage after PAO was a significant risk factor for conversion to THA and radiographic progression of osteoarthritis. Therefore, surgeons should attempt to prioritize the correction of the superior acetabular coverage when performing PAO.

Preoperative T2 mapping MRI of articular cartilage values predicts postoperative osteoarthritis progression following rotational acetabular osteotomy

AIMS

Rotational acetabular osteotomy (RAO) has been reported to be effective in improving symptoms and preventing osteoarthritis (OA) progression in patients with mild to severe develomental dysplasia of the hip (DDH). However, some patients develop secondary OA even when the preoperative joint space is normal; determining who will progress to OA is difficult. We evaluated whether the preoperative cartilage condition may predict OA progression following surgery using T2 mapping MRI.

METHODS

We reviewed 61 hips with early-stage OA in 61 patients who underwent RAO for DDH. They underwent preoperative and five-year postoperative radiological analysis of the hip. Those with a joint space narrowing of more than 1 mm were considered to have 'OA progression'. Preoperative assessment of articular cartilage was also performed using 3T MRI with the T2 mapping technique. The region of interest was defined as the weightbearing portion of the acetabulum and femoral head.

RESULTS

There were 16 patients with postoperative OA progression. The T2 values of the centre to the anterolateral region of the acetabulum and femoral head in the OA progression cases were significantly higher than those in patients without OA progression. The preoperative T2 values in those regions were positively correlated with the narrowed joint space width. The receiver operating characteristic analysis revealed that the T2 value of the central portion in the acetabulum provided excellent discrimination, with OA progression patients having an area under the curve of 0.858. Furthermore, logistic regression analysis showed T2 values of the centre to the acetabulum's anterolateral portion as independent predictors of subsequent OA progression (p < 0.001).

CONCLUSION

This was the first study to evaluate the relationship between intra-articular degeneration using T2 mapping MRI and postoperative OA progression. Our findings suggest that preoperative T2 values of the hip can be better prognostic factors for OA progression than radiological measures following RAO. Cite this article: Bone Joint J 2021;103-B(9):1472-1478.

Transpositional periacetabular osteotomy with allografting in patients with severe dysplasia: mid-term results

AIM

The purpose of this study was to analyse the extent of surgical correction and the early clinical results obtained using periacetabular osteotomy with allogenic bone grafting in patients with severe acetabular dysplasia.

METHODS

44 hips in 38 patients were confirmed to have severe acetabular dysplasia and underwent this procedure. The mean follow-up period was 4.2 (range 1.5-8.2) years. Severe acetabular dysplasia was defined as a centre-edge angle less than 0°, an acetabular-head index less than 50% and an acetabular roof obliquity greater than 30°. Periacetabular osteotomy was performed with transpositional osteotomy of the acetabulum. The patients were divided into 2 groups according to the radiographic appearance: 34 hips in the early stage group and 10 hips in the advanced stage group. Postoperatively, the hips were radiographically assessed for dysplasia correction. The clinical results and hip function were measured using the Harris Hip Score.

RESULTS

The average preoperative Harris Hip Score improved from 70 to 91 points at the latest follow-up. The average centre-edge angle, acetabular-head index and acetabular roof obliquity improved from -9° to 36°, 41% to 91% and 31° to 2°, respectively. Continuity of the Shenton line improved from 15 to 35 hips. No instances of nonunion or of transported segment collapse were encountered in this series; however, a grafted allogenic bone was absorbed in 1 case.

CONCLUSIONS

The usage of allogenic bone grafting combined with periacetabular osteotomy is an effective technique for treating severe acetabular dysplasia. In this series, the early clinical and radiographic results were excellent.

A pre-operative predictive score for the outcome of eccentric rotational acetabular osteotomy in the treatment of acetabular dysplasia and early osteoarthritis of the hip in adults

AIMS

The influence of identifiable pre-operative factors on the outcome of eccentric rotational acetabular osteotomy (ERAO) is unknown. We aimed to determine the factors that might influence the outcome, in order to develop a scoring system for predicting the prognosis for patients undergoing this procedure.

PATIENTS AND METHODS

We reviewed 700 consecutive ERAOs in 54 men and 646 women with symptomatic acetabular dysplasia or early onset osteoarthritis (OA) of the hip, which were undertaken between September 1989 and March 2013. The patients' pre-operative background, clinical and radiological findings were examined retrospectively. Multivariate Cox regression analysis was performed using the time from the day of surgery to a conversion to total hip arthroplasty (THA) as an endpoint. A risk score was calculated to predict the prognosis for conversion to THA, and its predictive capacity was investigated.

RESULTS

The congruity of the hip, age, the pre-operative minimum width of the joint space and range of abduction were identified as factors predicting conversion to THA. For three groups of patients (scoring 0 to 5, 6 to 7, and 8 to 9 points), the Kaplan-Meier event-free rates of survival at 15 years post-operatively for conversion to THA were 99.6%, 85.2% and 67.3%, respectively.

CONCLUSION

These four pre-operative factors are easily measured and predict the prognosis for patients following ERAO. They may be used for decision making when offering surgical treatment to patients with acetabular dysplasia and early onset osteoarthritis. Cite this article: Bone Joint J 2016;98-B:1326-32.

Do labral tears influence poor outcomes after periacetabular osteotomy for acetabular dysplasia?

AIMS

Acetabular dysplasia is frequently associated with intra-articular pathology such as labral tears, but whether labral tears should be treated at the time of periacetabular osteotomy (PAO) remains controversial. The purpose of this study was to compare the clinical outcomes and radiographic corrections of PAO for acetabular dysplasia between patients with and without labral tears pre-operatively.

PATIENTS AND METHODS

We retrospectively reviewed 70 hips in 67 patients with acetabular dysplasia who underwent PAO. Of 47 hips (45 patients) with labral tears pre-operatively, 27 (25 patients) underwent PAO alone, and were classified as the labral tear alone (LT) group, and 20 (20 patients) underwent combined PAO and osteochondroplasty, and were classified as the labral tear osteochondroplasty (LTO) group. The non-labral tear (NLT) group included 23 hips in 22 patients.

RESULTS

There were no significant differences between groups for post-operative Harris hip scores, degree of progression of osteoarthritis or rate of reoperation. The pre-operative alpha angle was significantly larger in the LTO group compared with the other groups (p < 0.0001).

CONCLUSION

PAO provides equivalent short-term relief of pain and functional outcome in patients with or without labral tears. The rate of progression of osteoarthritis and reoperation was not significantly increased in patients with labral tears.

TAKE HOME MESSAGE

PAO provides equivalent short-term pain relief and functional outcomes in patients with acetabular dysplasia with and without labral tears. We did not find significantly increased risks of progression of osteoarthritis or re-operation in those with labral tears. Cite this article: Bone Joint J 2016;98-B:741-6.

Preoperative prognosis score is a useful tool regarding eccentric rotational acetabular osteotomy in patients with acetabular dysplasia

BACKGROUND

It is unknown how possible preoperative factors influence the postoperative outcome of eccentric rotational acetabular osteotomy (ERAO). We aimed to determine these factors and to develop a scoring system for predicting the prognosis after ERAO in patients with symptomatic hip dysplasia.

PATIENTS

We included 700 patients (54 men, 646 women) who underwent ERAO during September 1989 to March 2013. The patients' clinical background, preoperative clinical findings, and preoperative imaging findings were examined retrospectively. Univariate and multivariate Cox regression were performed using the time from the day of surgery to a Harris hip score (HHS) <80 as an endpoint. A failure score was defined to predict the prognosis for an HHS <80, and its predictive capacity was assessed.

RESULTS

Ninety patients had an HHS <80. Forty-two patients underwent conversion to total hip arthroplasty (THA) after their HHS decreased to <80. Five factors were identified in relation to an HHS <80: a history of congenital dislocation of the hip, joint congruity, body mass index, the preoperative minimum joint space width, and the preoperative abduction range of motion. We estimated the weight of each factor using the results of multivariate Cox regression, and the outcome prediction scoring was obtained (0-17 points). For three groups of patients (total points of each factors: 0-5, 6-9, and ≥10 points), the Kaplan-Meier event-free survival rates at 15 years postoperatively for an HHS <80 were 97%, 81%, and 55%, respectively; the survival rates for THA conversion using this prediction scoring were 99%, 96%, and 85%, respectively.

CONCLUSIONS

Five preoperative factors can easily and clearly predict the prognosis following ERAO. The prognosis score may be a useful tool when making a decision regarding operative treatments in adult patients with acetabular dysplasia.

Curtain osteophytes are one of the risk factors for the poor outcome of rotational acetabular osteotomy

PURPOSE

Rotational acetabular osteotomy (RAO) is one of the surgical procedures for painful dysplastic hips. Although several risk factors for poor outcome of RAO have been reported, the presence of a curtain osteophyte in the acetabulum has not been evaluated as a possible risk factor. This study aimed to analyze the risk factors affecting the outcome of RAO and to clarify whether curtain osteophytes are one of the risk factors.

METHODS

We retrospectively analyzed 87 hips in 78 patients with a mean age of 36 (range, 13-54) years. The mean follow-up period was 8.3 (range, 2.1-19.5) years. The radiographic severity of osteoarthritis was classified into four stages: pre-arthrosis, initial stage, advanced stage, and terminal stage. The Japanese Orthopaedic Association (JOA) hip score was used for clinical evaluation. Poor outcome was defined as a hip with a JOA score < 80 points or terminal-stage osteoarthritis at final follow-up. Several factors were evaluated by logistic regression analysis.

RESULTS

At final follow-up, ten hips had a JOA score < 80 and nine hips had progressed to terminal-stage osteoarthritis. Since five hips had a JOA score < 80 as well as terminal-stage osteoarthritis, a total of 14 hips were determined to have poor outcome. An additional ten years of age at surgery, pre-operative minimal joint space < 2 mm, presence of a curtain osteophyte, and fair/poor congruency in abduction were identified as significant risk factors for poor outcome of RAO.

CONCLUSIONS

Hips with curtain osteophyte should be evaluated carefully before RAO.

Does Previous Hip Surgery Effect the Outcome of Tönnis Triple Periacetabular Osteotomy? Mid-Term Results

Hip dysplasia (HD) is 1 of the major reasons of coxarthrosis. The goal of the treatment of HD by Tönnis triple pelvic osteotomy (TPAO) is to improve the function of hip joint while relieving pain, delaying and possibly preventing end-stage arthritis. The aim of this study is to compare the clinical and radiological results of TPAO to determine if previous surgery has a negative effect on TPAO.Patients operated with TPAO between 2005 and 2010, included in this study. Patients divided into 2 groups: primary acetabular dysplasia (PAD) and residual acetabular dysplasia (RAD). Prepostoperatively, hip range of motion, Harris hip score (HHS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) hip score, visual analog scores (VAS), impingement tests, and also the presence of Trendelenburg sign (TS) were investigated for clinical evaluation. For radiological analysis pre-postoperative, anterior-posterior (AP) pelvis and faux profile radiographs were used. Acetabular index, lateral center edge (LCE) angle, and Sharp angles were measured by AP pelvis; anterior center edge (ACE) angle were measured by faux profile radiography. All the clinical and radiological data of the groups were analyzed separately for the pre-postoperative scores also the amount of improvement in all parameters were analyzed.SPSS20 (SPSS Inc., Chicago, IL) was used for statistical analysis. Wilcoxon test, McNemar test, paired t tests, and Mann-Whitney U tests were used to compare the groups. P < 0.05 were defined as statistically significant.Study included 27 patients: 17 patients were in PAD and 10 patients were in RAD. The mean follow-up period was 6.2 years (5.2-10.3 years). In all patients, the radiological and the clinical outcomes were better after TPAO except the flexion of the hip parameter. When the patient groups were evaluated as pre-postoperatively, more statistically significant parameters were found in the PAD group when compared with RAD group. Extension, impingement, TS, VAS, HHS, WOMAC score parameters in clinical outcome and LCE, ACE, Sharp angle, coverage ratio in radiological results were significantly better in PAD group postoperatively but in RAD group; only extension, VAS, HHS, and WOMAC parameters were clinically and LCE and Coverage ratio were significantly different compared with the preoperative measurements. The change of the parameters that used for the evaluation of clinical and radiological results did not show a significant difference between groups.Our data suggest that TPAO can be performed on patients with HD for both groups. Although there were fewer parameters which changed significantly after TPAO in RAD patients; the improvement of radiological and clinical results was similar for groups. Further long-term follow-up studies with large number of patients are needed to determine the proper results of TPAO.

No correlations between radiological angles and self-assessed quality of life in patients with hip dysplasia at 2-13 years of follow-up after periacetabular osteotomy

BACKGROUND

Only few studies have described patients' health-related quality of life (QoL) after periacetabular osteotomy (PAO). Thus, there is a lack of data on the self-assessed outcome of patients operated with PAO, and none of the existing studies correlate the results from Medical Outcomes Short Form-36 questionnaire (SF-36) with the radiological parameters.

PURPOSE

To investigate the health-related QoL for patients with hip dysplasia operated with PAO and to investigate whether QoL is associated with the acetabular angles or hypermobility.

MATERIAL AND METHODS

Out of 388 patients, 228 patients (mean age, 40.5 years; mean follow-up, 7.1 years) returned the SF-36 and Beighton questionnaires. The patient's QoL was compared to reference data from a Danish population. Center-edge (CE) and acetabular index (AI) angles were measured before and after PAO and the association with the patients' QoL was tested with logistic regression.

RESULTS

For both men and women the postoperative SF-36 score was significantly lower than for the reference data for a Danish population, especially for those dimensions concerning physical health. No association was found between the patients' CE or AI angles before or after PAO and their subsequent QoL. Significant associations were found between both Physical Component Score (PCS) and physical function (PF) and follow-up time after the operation. The adjusted OR for a PCS ≥ 50 was 0.87 (95% CI 0.76-0.99) and for a PF ≥ 85 0.81 (95% CI 0.71-0.91). No association between hyper mobility and PCS, PF, or bodily pain (BP) was found.

CONCLUSION

The physical components of QoL in patients undergoing PAO are significantly lower than the Danish population used as reference. Furthermore, the results suggest that physical function after PAO decreases with longer follow-up time. Neither the acetabular angles nor hypermobility is associated with the physical components of QoL.

Effect of intra-articular lesions on the outcome of periacetabular osteotomy in patients with symptomatic hip dysplasia

In order to clarify how intra-articular lesions influence the survival of a periacetabular osteotomy in patients with dysplasia of the hip, we performed an observational study of 121 patients (121 hips) who underwent a transposition osteotomy of the acetabulum combined with an arthroscopy. Their mean age was 40.2 years (13 to 64) and the mean follow-up was 9.9 years (2 to 18). Labral and cartilage degeneration tended to originate from the anterosuperior part of the acetabulum, followed by the femoral side. In all, eight hips (6.6%) had post-operative progression to Kellgren–Lawrence grade 4 changes, and these hips were associated with the following factors: moderate osteoarthritis, decreased width of the joint space, joint incongruity, and advanced intra-articular lesions (subchondral bone exposure in the cartilage and a full-thickness labral tear). Multivariate analysis indicated subchondral bone exposure on the femoral head as an independent risk factor for progression of osteoarthritis (p = 0.003). In hips with early stage osteoarthritis, femoral subchondral bone exposure was a risk factor for progression of the grade of osteoarthritis.

Although the outcome of transposition osteotomy of the acetabulum was satisfactory, post-operative progression of osteoarthritis occurred at a high rate in hips with advanced intra-articular lesions, particularly in those where the degenerative process had reached the point of femoral subchondral bone exposure.

Joint space wider than 2 mm is essential for an eccentric rotational acetabular osteotomy for adult hip dysplasia

BACKGROUND

Satisfactory intermediate-term results after an eccentric rotational acetabular osteotomy (ERAO) for the treatment of early osteoarthritis secondary to developmental dysplasia of the hip (DDH) have been reported. The purpose of this study was to investigate whether a minimum joint space width (JSW) in patients with advanced osteoarthritis secondary to DDH influences intermediate-term clinical and radiographic outcomes after performing an ERAO.

METHODS

A total of 113 patients (116 hips) with a JSW of ≤3 mm were consecutively treated by ERAO for advanced osteoarthritis of the hip and then were followed for more than 5 years. Based on the preoperative JSW, the patients were divided into three groups: minimum JSW of ≤1 mm (JS1 group); JSW >1 mm but ≤2 mm (JS2 group); JSW > 2 mm but ≤3 mm (JS3 group). The average ages of the JS1, JS2, and JS3 patients were 40, 44, and 43 years, respectively. The average follow-up period was 10.6 years.

RESULTS

Overall conversion to total hip arthroplasty (THA) was performed in 14 joints. According to a Kaplan-Meier survivorship analysis at 15 years after the index operation, 96% of the patients with a JSW of >2 mm (JS3 group) did not require conversion to THA.

CONCLUSIONS

A JSW of >2 mm before surgery is considered essential to obtain an excellent intermediate-term result following performance of an ERAO.

Periacetabular osteotomy: a systematic literature review

The Bernese periacetabular osteotomy is commonly used to treat symptomatic acetabular dysplasia. Although periacetabular osteotomy is becoming a more common surgical intervention to relieve pain and improve function, the strength of clinical evidence to support this procedure for these goals is not well defined in the literature. We therefore performed a systematic review of the literature to define the level of evidence for periacetabular osteotomy, to determine deformity correction, clinical results, and to determine complications associated with the procedure. Thirteen studies met our inclusion criteria. Eleven studies were Level IV, one was Level III, and one was Level II. Radiographic deformity correction was consistent and improvement in hip function was noted in all studies. Most studies did not correlate radiographic and clinic outcomes. Clinical failures were commonly associated with moderate to severe preoperative osteoarthritis and conversion to THA was reported in 0% to 17% of cases. Major complications were noted in 6% to 37% of the procedures. These data indicate periacetabular osteotomy provides pain relief and improved hip function in most patients over short- to midterm followup. The current evidence is primarily Level IV.

LEVEL OF EVIDENCE

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

Transposition osteotomy of the acetabulum for advanced-stage osteoarthritis of the hips

BACKGROUND

Transposition osteotomy of the acetabulum (TOA) was the first periacetabular osteotomy in which the acetabulum was transposed with articular cartilage. TOA improves coverage of the femoral head and joint congruity. The purpose of this study was to investigate whether TOA is an appropriate option for treating osteoarthritis of the hips at the advanced stage by comparing it with matched control hips at the early stage.

METHODS

Between 1998 and 2001, TOA was performed in 104 hips of 98 patients. Altogether, 16 of 17 hips (94%) with osteoarthritis at the advanced stage were examined and compared with 37 matched control hips at the early stage. The mean age at the operation was 48 years (38-56 years), and the mean follow-up period was 88 months (65-107 months).

RESULTS

TOA corrected the acetabular dysplasia and significantly improved containment of the femoral head. Clinical scores were also significantly improved in both groups. In the advanced osteoarthritis cases, there was a tendency for abduction congruity before transposition osteotomy of the acetabulum to reflect the clinical outcome.

CONCLUSIONS

TOA is a promising treatment option for advanced osteoarthritis of the hips as well as for patients at an early stage when preoperative radiographs show good congruity or containment of the joint.

[Indications and results of corrective pelvic osteotomies in developmental dysplasia of the hip]

BACKGROUND

Joint-preserving reconstructive surgeries in children and adolescents remain challenging for orthopaedists with regard to indication and surgical technique. Besides skeletal maturity and tissue quality at the time of surgery, the kind and degree of deformity, the causative pathologies in secondary dysplasias, and the prognosis have to be considered when deciding for or against a surgical procedure. Developmental dysplasia of the hip (DDH) is the most frequent deformity that indicates reorienting surgery on the hip joint in children and adolescents. The aim of these procedures is to prevent early secondary osteoarthritis. For patients and families as well as for the orthopaedist, risk-benefit analysis is of major interest.

METHODS

In this study, the surgical techniques and specialties of different reconstructive operations are presented. Based on a review of the literature, the results of defined surgical methods are discussed and compared with own experiences.

RESULTS

Only limited information is available about the clinical long-term outcome after defined reconstructing surgery on the hip joint in children and adolescents. The degree of the deformity, the age of onset, and the surgical experience of the orthopaedist are crucial factors in decision making for or against a surgical treatment. In early childhood, acetabuloplasty and Salter osteotomy are widely accepted to correct DDH. Triple and periacetabular osteotomies are preferred and have shown promising results in late adolescence and young adults. When the triradiate cartilage (growth plate) is closed, good outcomes can be achieved by the Ganz osteotomy. Intertrochanteric varus and derotation osteotomies of the femur may serve as additional procedures for pelvic osteotomies and are rarely indicated as a single procedure today.

CONCLUSION

Reconstructive surgery on the hip joint improves function and may prevent early osteoarthritis and delay progression of cartilage degeneration in most patients when the indication and surgical technique are appropriate.

Factors leading to osteoarthritis after eccentric rotational acetabular osteotomy

We performed eccentric rotational acetabular osteotomy consecutively in 273 hips in 248 patients with hip dysplasia. Twenty-one patients were male and 227 were female. The average age was 37.7 years at the time of the index operation. Twenty-two hips had no osteoarthritis, 129 had early osteoarthritis, 117 had advanced osteoarthritis, and five had end-stage osteoarthritis. Twenty-six hips also were treated with concomitant intertrochanteric valgus osteotomy. Patients were followed for a minimum of 5 years after surgery. The average Harris hip score improved from 71 points preoperatively to 92 points at the final followup. Nine hips were converted to total hip arthroplasty as a result of deterioration after surgery. Kaplan-Meier survivorship analysis 15 years after the index operation indicated 97% in pre- and early stages and 87% in advanced and end stages when the end point was total hip arthroplasty. Risk factors identified by multivariate analysis for development of osteoarthritis of the hip 5 years after the index operation were body mass index (24 kg/m2 or more), concomitant valgus osteotomy, operative year between 1989 and 1992, a postoperative center-edge angle of Wiberg less than 25 degrees , and a postoperative horizontal distance of the femoral head from the tear drop (40 mm or more).

LEVEL OF EVIDENCE

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

A computer simulation of rotational acetabular osteotomy for dysplastic hip joint: does the optimal transposition of the acetabular fragment exist?

For young patients who have early signs of coxarthrosis resulting from acetabular dysplasia, periacetabular osteotomies for correcting abnormal stress distribution can be useful for preventing the progression of the disease. However, it is difficult to confirm the optimal transposition of the osteotomized acetabular fragment. To deal with this problem, we devised a computer program to support preoperative planning. Hip images obtained by computed tomography were loaded into our program, and a three-dimensional voxel model was created. Then, osteotomy was simulated and the pressure distribution was analyzed with a rigid-body spring analysis (computational nonlinear mechanical analysis). The three-dimensional pressure distributions in seven dysplastic hips were evaluated before and after virtual rotational acetabular osteotomy. A peak pressure was calculated for every 5 degrees of rotation of the acetabular fragment. The peak pressure decreased gradually and increased again afterward, indicating the optimal transposition of the acetabular fragment. The postoperative peak pressure decreased to about 40% in the most improved case. This program allows the hip joint mechanics to be evaluated easily so that the advantages and disadvantages of various surgical methods can be examined biomechanically prior to surgery.

Triple osteotomy of the pelvis for acetabular dysplasia: age at operation and the incidence of nonunions and other complications influence outcome

We investigated the variables which determine the outcome after triple osteotomy of the pelvis for the treatment of congenital dysplasia of the hip. We reviewed 51 patients (61 hips) with a median age at operation of 23 years who were treated with a Tönnis triple osteotomy. The median follow-up was six years with a minimum of two years. Eight patients (eight hips) required a revision procedure. Of the remaining 53 hips, the results were good or excellent in 36 (68%) when evaluated according to the Harris hip score (median 90 points), and 33 patients (65%) were satisfied with the procedure. Logistic regression analysis indicated that the incidence of complications such as nonunion at an osteotomy site influenced patient satisfaction (p = 0.079). The incidence of complications correlated positively with increasing patient age at operation (p = 0.004). The amount of acetabular correction did not correlate with patient satisfaction. In univariate analysis, the groups of 'satisfied' and 'not satisfied' patients differed significantly in Harris hip score, age, incidence of nonunion at the osteotomy sites, complications and late revisions. In conclusion, the patient's age at operation and the incidence of complications influence patient satisfaction after triple osteotomy, but the amount of radiologically evident acetabular correction shows no correlation to outcome.