Periacetabular osteotomy through a modified ollier transtrochanteric approach for treatment of painful dysplastic hips

BACKGROUND: Elimination of abnormally high joint-loading resulting in excessive contact stresses may prevent or reduce the onset of osteoarthrosis in a dysplastic hip. A number of periacetabular osteotomies have been shown to be effective in restoring normal hip-joint mechanics. We treat acetabular dysplasia with a periacetabular osteotomy performed through a modified Ollier transtrochanteric approach. In this report, we describe the operative technique and the clinical and radiographic results. METHODS: Thirty-six patients (thirty-eight hips) in whom a painful dysplastic hip had been treated with a periacetabular osteotomy between March 1991 and June 1999 were included in the study. There were thirty-five female patients and one male patient with a mean age (and standard deviation) at the operation of 29.42 +/- 9.1 years. The technique utilizes a u-shaped skin incision, and a routine osteotomy of the greater trochanter with distal transfer if needed, and allows excellent visualization enabling the surgeon to perform the periacetabular osteotomy without penetrating the joint. RESULTS: At a mean of five years and six months postoperatively, the mean modified Harris hip score had improved from 59.1 +/- 15.8 points preoperatively to 87.97 +/- 14.3 points. Radiographically, the degree of osteoarthrosis had decreased in eleven hips, remained unchanged in twenty-four, and worsened in three. The mean anterior center-edge angle had increased from 22.0 degrees +/- 12.9 degrees to 36.1 degrees +/- 12.3 degrees, the mean lateral center-edge angle had increased from -2.7 degrees +/- 14.4 degrees to 26.6 degrees +/- 14.1 degrees, the mean acetabular index angle had improved from 23.4 degrees +/- 6.6 degrees to 12.7 degrees +/- 4.6 degrees, and the mean acetabular head index had increased from 48.2% +/- 12.7% to 73.1% +/- 16.0%. The Shenton line was restored in eleven hips. Thirty patients (thirty-two hips; 84%) had a satisfactory result. A poor preoperative functional score was associated with an unsatisfactory outcome (p = 0.00191). Complications included prolonged limping (eleven hips); numbness in the distribution of the lateral femoral cutaneous nerve (four); osteonecrosis of the rotated acetabular fragment (two); and acetabulofemoral impingement, heterotopic ossification, and a defect on the rotated ilium (one hip each). CONCLUSIONS: Painful dysplastic hips should be treated before function becomes seriously impaired. We believe that periacetabular osteotomy through a modified Ollier approach, which allows osseous cuts to be made under direct vision, can be learned readily. It provides improved femoral head coverage and relief of symptoms in most painful dysplastic hips in adolescents and young adults.     

The Bernese periacetabular osteotomy: clinical, radiographic and mechanical 7-15-year follow-up of 26 hips

BACKGROUND: The Bernese periacetabular osteotomy is used in dysplastic hips to increase the load-bearing area of the hip and to prevent osteoarthritis.The aim of our work was to determine the contact hip stress before and after the osteotomy and to compare the relief of stress with the long-term radiographic and clinical outcome. PATIENTS AND METHODS: We followed 26 dysplastic hips (26 patients) for 7-15 years after the index operation. Clinical evaluation was based on the WOMAC score, osteoarthrosis was evaluated with the T?nnis classification, the angles of lateral (CE) and anterior (VCA) femoral coverage were measured, and biomechanical parameters were studied. RESULTS: Periacetabular osteotomy increased the mean CE from 15 degrees to 37 degrees , and the mean VCA from 22 degrees to 38 degrees . The mean normalized peak contact stress was reduced from 5.2 to 3.0 kPa/N. Four hips required total hip arthroplasty after an average of 4.5 years, 8 hips showed considerable arthrosis progression, and 14 hips had no or mild arthrosis at follow-up. Preoperative WOMAC score, preoperative T?nnis grade and postoperative normalized peak contact stress were the most important predictors of outcome. INTERPRETATION: The Bernese periacetabular osteotomy improves the mechanical status of the hip. Long-term success depends on the grade of arthrosis preoperatively and on the magnitude of operative correction of the contact hip stress.     

Periacetabular osteotomy for the treatment of severe acetabular dysplasia

BACKGROUND: The optimal treatment of severe acetabular dysplasia with subluxation of the femoral head or the presence of a secondary acetabulum remains controversial. The purpose of this study was to analyze the extent of surgical correction and the early clinical results obtained with the Bernese periacetabular osteotomy for the treatment of severely dysplastic hips in adolescent and young adult patients. METHODS: Sixteen hips in thirteen patients with an average age of 17.6 years (range, 13.0 to 31.8 years) were classified as having severe acetabular dysplasia (Group IV or V according to the Severin classification). Eight hips were classified as subluxated, and eight had a secondary acetabulum. Preoperatively, all patients had hip pain and sufficient hip joint congruency on radiographs to be considered candidates for the osteotomy. All sixteen hips underwent a Bernese periacetabular osteotomy, and six of them underwent a concomitant proximal femoral osteotomy. Postoperatively, the hips were assessed radiographically to evaluate correction of deformity, healing of the osteotomy site, and progression of osteoarthritis. Clinical results and hip function were measured with the Harris hip score at an average of 4.2 years postoperatively. RESULTS: Comparison of preoperative and follow-up radiographs demonstrated an average improvement of 44.6 degrees (from -20.5 degrees to 24.1 degrees ) in the lateral center-edge angle of Wiberg, an average improvement of 51.0 degrees (from -25.4 degrees to 25.6 degrees ) in the anterior center-edge angle of Lequesne and de Seze, and an average improvement of 25.9 degrees (from 37.3 degrees to 11.4 degrees ) in acetabular roof obliquity. The hip center was translated medially an average of 10 mm (range, 0 to 31 mm). All iliac osteotomy sites healed. The average Harris hip score improved from 73.4 points preoperatively to 91.3 points at the time of the latest follow-up. Eleven of the thirteen patients (fourteen of the sixteen hips) were satisfied with the result of the surgery, and fourteen hips had a good or excellent clinical result. Major complications included loss of acetabular fixation, which required an additional surgical procedure, in one patient and overcorrection of the acetabulum and an associated ischial nonunion in another patient. Both patients had a good clinical result at the time of the latest follow-up. There were no major neurovascular injuries or intra-articular fractures. CONCLUSIONS: The periacetabular osteotomy is an effective technique for surgical correction of a severely dysplastic acetabulum in adolescents and young adults. In this series, the early clinical results were very good at an average of 4.2 years postoperatively; the two major complications did not compromise the good clinical results.     

伯尔尼髋臼周围截骨术对严重髋臼发育不良的治疗

目的 研究和分析使用伯尔尼髋臼周围截骨术治疗严重髋臼发育不良的中期临床和影像学结果.方法 1997年10月至2002年12月对18例(20髋)严重髋臼发育不良(Severin分级Ⅳb级)的患者接受了伯尔尼髋臼周围截骨术.患者手术时平均年龄21岁,平均随访时间6.2年.本组患者术前患髋均已出现疼痛,术前功能位片显示关节面吻合.术后影像学评价畸形的矫正范围,截骨处的愈合情况及关节炎的进展.临床结果和髋关节功能由Harris评分进行评价,术前Harris评分平均78.5分.结果 比较术前和术后X线片,外侧中心边缘角(CE角)、前方CE角和臼顶倾斜角均有显著改善.所有髂骨截骨均愈合.患者术后末次随访Harris评分平均91.1分.18例患者中的14例对手术效果表示满意.20髋中16髋临床结果优.但有5髋存在畸形矫正不足.结论 伯尔尼髋臼周围截骨术是治疗严重髋臼发育不良的有效术式.这一截骨术可以在各个平面对严重的骨缺损进行矫正,中期临床结果令人满意.     

Early results of the Bernese periacetabular osteotomy: the learning curve at an academic medical center

BACKGROUND: Most reports on the results of the Bernese periacetabular osteotomy for the treatment of developmental dysplasia of the hip have been by the originators of the procedure. In 1997, we began to use this osteotomy without direct training from the originators of the procedure. METHODS: Seventy-three patients (eighty-three hips) underwent a Bernese periacetabular osteotomy between 1997 and 2003 and were followed prospectively with use of the Harris hip score to assess clinical results and with use of anteroposterior pelvic and false-profile lateral plain radiographs to assess radiographic results. The three-dimensional position of the acetabulum was recorded preoperatively and postoperatively. The mean duration of follow-up was forty-six months. RESULTS: The average Harris hip score improved from 54 to 87 points (p < 0.001). Three hips (three patients) had a conversion to total hip arthroplasty at two, three, and four years after the periacetabular osteotomy. Preoperatively, fifty-four of the eighty-three acetabula were anteverted, and twenty-nine were either retroverted or had neutral wall relationships. Postoperatively, sixty-five hips (78%) were anteverted. Radiographically, in preoperatively anteverted hips, the average center-edge angle improved from 3 degrees to 29 degrees (p < 0.0001), the average anterior center-edge angle improved from 5 degrees to 31 degrees (p < 0.0001), and the acetabular index improved from 25 degrees to 5 degrees (p < 0.0001). In preoperatively retroverted or neutral hips, the average center-edge angle improved from 13 degrees to 33 degrees (p < 0.0001), the average anterior center-edge angle improved from 15 degrees to 36 degrees (p < 0.0001), and the acetabular index improved from 19 degrees to 2 degrees (p < 0.0001). Complications included four hematomas, three transient femoral nerve palsies, two deep wound infections, and one transient sciatic nerve palsy. Nine of the ten major complications and all four of the failed osteotomies occurred in the first thirty hips in which the index procedure was performed. CONCLUSIONS: In our experience, the early results of the Bernese periacetabular osteotomy have been encouraging, with a 92% survival rate at thirty-six months. The occurrence of complications demonstrates a substantial learning curve. Recognition of the true preoperative acetabular version and reorientation of the acetabulum into an appropriately anteverted position have become important factors in surgical decision-making. LEVEL OF EVIDENCE: Therapeutic Level IV.     

Surgical correction of acetabular dysplasia in the adult. A Boston experience.

Acetabular redirection surgery is the mainstay of treatment for the symptomatic, dysplastic hip. The authors' experience with the Salter innominate osteotomy, Wagner spherical acetabular osteotomy and the modified Bernese periacetabular osteotomy shows that major acetabular redirection surgery can reliably improve the structure of the dysplastic hip and delay or prevent secondary osteoarthrosis. The limited correction achieved by the Salter innominate osteotomy suggests this procedure generally should be reserved for younger patients with mild dysplasia. The modified Bernese periacetabular osteotomy is the authors' current preferred method of treating acetabular dysplasia, even in the presence of mild to moderate secondary osteoarthrosis.     

Periacetabular osteotomy in the treatment of neurogenic acetabular dysplasia

We carried out the Bernese periacetabular osteotomy for the treatment of 13 dysplastic hips in 11 skeletally mature patients with an underlying neurological diagnosis. Seven hips had flaccid paralysis and six were spastic. The mean age at the time of surgery was 23 years and the mean length of follow-up was 6.4 years. Preoperatively, 11 hips had pain and two had progressive subluxation. Before operation the mean T?nnis angle was 33 degrees, the mean centre-edge angle was -10 degrees, and the mean extrusion index was 53%. Postoperatively, they were 8 degrees, 25 degrees and 15%, respectively. Pain was eliminated in 7 patients and reduced in four in those who had preoperative pain. One patient developed pain secondary to anterior impingement from excessive retroversion of the acetabulum. Four required a varus proximal femoral osteotomy at the time of the pelvic procedure and one a late varus proximal femoral osteotomy for progressive subluxation. Before operation no patient had arthritis. At the most recent follow-up one had early arthritis of the hip (T?nnis grade I) and one had advanced arthritis (T?nnis grade III). Our results suggest that the Bernese periacetabular osteotomy can be used successfully to treat neurogenic acetabular dysplasia in skeletally mature patients.     

Periacetabular osteotomy: preoperative radiographic predictors of outcome

Periacetabular osteotomy is an extremely effective treatment for the spherical dysplastic hip without significant secondary osteoarthrosis. Yet, the reliability of the procedure in patients with some degree of secondary osteoarthritis, asphericity, or associated deformities remains undefined. The purpose of the current study was to analyze a group of patients treated by periacetabular osteotomy for dysplasia to identify preoperative factors that predict outcome. Ninety-five consecutive hips in 87 patients treated by periacetabular osteotomy were studied prospectively. Of this group, 52 hips in 49 patients were studied for a minimum of 2 years after surgery. Forty-six of the 52 procedures resulted in hips with stable or improved cartilage space intervals. By Tonnis category, there were 0 of 21 failures in Grade 1, four of 22 failures in Grade 2 (18%), one of eight failures in Grade 3 (12.5%), and one of one failure in Grade 4 hips. Five of the six failures had factors identifiable on preoperative radiographs that separated these hips from the successful reconstructions. This study shows that periacetabular osteotomy can reliably produce a stable hip, even in the presence of Grade 3 arthrosis, provided that the joint shows an improved cartilage space interval on the preoperative functional radiographs.     

The Bernese periacetabular osteotomy: clinical,radiographic and mechanical 7–15-year follow-up of 26 hips

Background?The Bernese periacetabular osteotomy is used in dysplastic hips to increase the load-bearing area of the hip and to prevent osteoarthritis.The aim of our work was to determine the contact hip stress before and after the osteotomy and to compare the relief of stress with the long-term radiographic and clinical outcome.

Patients and methods?We followed 26 dysplastic hips (26 patients) for 7–15 years after the index operation. Clinical evaluation was based on the WOMAC score, osteoarthrosis was evaluated with the Tönnis classification, the angles of lateral (CE) and anterior (VCA) femoral coverage were measured, and biomechanical parameters were studied.

Results?Periacetabular osteotomy increased the mean CE from 15° to 37°, and the mean VCA from 22° to 38°. The mean normalized peak contact stress was reduced from 5.2 to 3.0 kPa/N. Four hips required total hip arthroplasty after an average of 4.5 years, 8 hips showed considerable arthrosis progression, and 14 hips had no or mild arthrosis at follow-up. Preoperative WOMAC score, preoperative Tönnis grade and postoperative normalized peak contact stress were the most important predictors of outcome.

Interpretation?The Bernese periacetabular osteotomy improves the mechanical status of the hip. Long-term success depends on the grade of arthrosis preoperatively and on the magnitude of operative correction of the contact hip stress.

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The periacetabular osteotomy. Minimum 2 year followup in more than 100 hips.

The results of 123 periacetabular osteotomies in 115 patients were reviewed at an average clinical followup of 4.3 years. The average age of the patients at the time of the operation was 32.9 years. The preoperative diagnosis was congenital dysplasia in 101 hips, Legg-Calve-Perthes disease in 10 hips, Charcot Marie Tooth disease in four hips, epiphyseal dysplasia in three hips, congenital coxa vara in two hips, slipped capital femoral epiphysis in one hip, and posttraumatic and postinfectious dysplasia in one hip each. The ilioinguinal approach was used in 67 hips and the modified Smith-Petersen approach was used in 56 hips. A periacetabular osteotomy was combined with an intertrochanteric osteotomy and/or trochanteric transfer in 32 hips. Ten hips underwent open reduction and internal fixation of an acetabular rim fracture and 18 arthrotomies were performed at the time of periacetabular osteotomy. The average Harris hip score increased from 65 points preoperatively to 89 points at latest followup. The average Merle d'Aubigne score increased from 13.6 points preoperatively to 16.3 points at latest followup. Overall, 83% of the hips were rated clinically as good to excellent. Seven hips have undergone total hip arthroplasty and six subsequent intertrochanteric osteotomies were performed. The majority of the major complications occurred when the osteotomy was performed through the ilioinguinal approach. The latest followup radiographic severity of osteoarthrosis, according to the criteria of T?nnis, improved or was unchanged in 117 hips (95%), and progressed in only six hips (5%). The majority of the hips with preoperative changes in the periarticular bone showed some evidence of regeneration, which was shown by a decrease in the subchondral sclerosis, disappearance of cysts, or healing of an acetabular rim fracture. The short term results of the periacetabular osteotomy are encouraging from the standpoint of improvements in clinical scores and in the appearance of the joint.     

Rapidly Progressive Osteoarthritis After Arthroscopic Labral Repair in Patients With Hip Dysplasia

Recent reports of poor clinical outcomes after arthroscopic surgery in hips with marked dysplasia have emerged. Arthroscopic resection of the hypertrophic labrum in cases of dysplasia, especially in the absence of periacetabular osteotomy (PAO), has been implicated. Some patients will refuse PAO because it is a major open procedure, opting for a less invasive arthroscopic procedure. We present the cases of 2 young adults with marked dysplasia who had rapidly progressive osteoarthrosis despite arthroscopic labral repair. Though perhaps beneficial as an isolated procedure in borderline or mild dysplasia cases, arthroscopic hip surgery, even labral repair, may best be performed with PAO in cases with more severe dysplasia. Albeit attractive as a less invasive labral-preserving surgery, arthroscopic labral repair not only may fail to provide symptomatic improvement but may compromise or preclude a later PAO if rapidly progressive osteoarthrosis ensues. Hip arthroscopy may best be performed concurrently with or after PAO but not proceeding PAO in patients requiring both procedures.     

Medium-term results of the Bernese periacetabular osteotomy in the treatment of symptomatic developmental dysplasia of the hip

We studied the medium-term outcome of the Bernese periacetabular osteotomy in 52 patients (58 hips) with symptomatic developmental dysplasia of the hip and a mean age of 37.6 years (13 to 48). The operations were performed between 1993 and 2005 by the senior author with a mean follow-up of 66.7 months (13 to 153). There were 42 women (47 hips) and ten men (11 hips). Of these patients, 24 (30 hips) had an osteotomy on the right side and 22 (28 hips) on the left. Six patients had bilateral operations. The clinical outcome was assessed using the modified Merle d'Aubigne scale, and pre- and post-operative radiological evaluation using the modified Tonnis osteoarthritis score, the centre-edge angle, the acetabular index, the status of Shenton's line, and the cross-over sign. The mean centre-edge angle and the acetabular index were 14 degrees (2 degrees to 34 degrees ) and 23.6 degrees (0 degrees to 40 degrees ) before operation, and 36.6 degrees (16 degrees to 72 degrees ) and 7.9 degrees (0 degrees to 28 degrees ) after, respectively (p < 0.001, analysis of variance (ANOVA)). Shenton's line was intact in 23 hips (39.6%) before operation and in 48 hips (82.8%) after. The cross-over sign was present in 31 hips (53.4%) before and in three hips (5.2%) after operation (p < 0.001, ANOVA). The total Merle d'Aubigne clinical score improved from a mean of 12.6 (9 to 15) to 16.0 (12 to 18) points (p < 0.001, ANOVA). Only four hips required subsequent total hip replacement. Our results indicate that the Bernese periacetabular osteotomy provides good symptomatic relief for patients with little to no arthritis (Tonnis type 0 or 1) with an underlying deformity that can be corrected to a position of a stable, congruent hip joint.     

Magnetic resonance imaging pelvimetry before and after a periacetabular osteotomy

BACKGROUND: The majority of patients who undergo a reconstructive pelvic osteotomy because of symptomatic hip dysplasia are young women of childbearing potential. The purpose of this paper was to evaluate the effect of periacetabular osteotomy on the dimensions of the pelvic inlet and outlet in these patients. METHODS: The dimensions of the osseous pelvis of seven women with symptomatic hip dysplasia were measured with use of magnetic resonance imaging pelvimetry before and after periacetabular osteotomy. Four measurements were made: the bispinous diameter, the anterior-posterior inlet measurement, the anterior-posterior midpelvis measurement, and the transverse inlet measurement. Radiographic correction obtained with the osteotomy was documented with preoperative and postoperative anteroposterior pelvic and false-profile radiographs. RESULTS: Periacetabular osteotomy improved the T nnis angle and the Lequesne angle of the hip joint to an average of 8 degrees and 30 degrees, respectively. The hip center of rotation was medialized an average of 8 mm. None of the four measurements made with the magnetic resonance imaging pelvimetry decreased substantially after the periacetabular osteotomy. CONCLUSION: Periacetabular osteotomy does not markedly alter the pertinent pelvic dimensions in young female patients.     

Early experience and results with the periacetabular osteotomy. The Mayo Clinic experience.

The purpose of the present study was to review the early results of periacetabular osteotomy in the initial group of patients undergoing this procedure at the authors' institution. The first 21 hips in 19 patients with greater than 2 years followup, which represents the learning curve with this operation, were reviewed retrospectively. There were 14 females and five males with an average age of 21 years (range, 17-43 years). Intertrochanteric osteotomy was performed simultaneously on four patients with coxa valga and inadequate correction with periacetabular osteotomy alone. At an average of 38 months of followup (range, 24-52 months), the Mayo hip scores improved from an average of 46 points (range, 34-58 points) to an average of 68 points (range, 42-80 points). Hip range of motion declined slightly in all three arcs of motion. The lateral center edge angle of Wiberg improved from an average of 2 degrees to an average of 24 degrees. The loading zone angle (T?nnis) improved from an average of 24 degrees to an average of 11 degrees. The anterior center edge angle of Lequesne improved from an average of -6 degrees to an average of 38 degrees. Complications included two peroneal palsies, both of which resolved completely; three ischial fractures that healed uneventfully; three asymptomatic pubic nonunions; and asymptomatic heterotopic ossification in five patients. One patient underwent subsequent total hip arthroplasty for progressive arthritis and pain. Another patient required intertrochanteric osteotomy at a later date. The early results in this initial group of patients treated with periacetabular osteotomy show reliable radiographic correction of deformity and improved function with an acceptable complication rate. Patients should be counseled carefully about possible loss of motion postoperatively. Additional study is necessary to assess the long term results of this procedure.     

Periacetabular osteotomy for the treatment of acetabular dysplasia associated with major aspherical femoral head deformities

BACKGROUND: Acetabular dysplasia associated with deformity of the proximal part of the femur can result in hip dysfunction and degenerative arthritis in young adults. The optimal method of surgical correction for these challenging combined deformities remains controversial. METHODS: We retrospectively analyzed twenty-four hips in twenty patients who underwent a Bernese periacetabular osteotomy, which was done with a proximal femoral valgus-producing osteotomy in thirteen hips, for the treatment of acetabular dysplasia associated with proximal femoral structural abnormalities. The average age of the patients at the time of surgery was 22.7 years, and the average duration of clinical follow-up was 4.5 years. The Harris hip score and overall patient satisfaction with surgery were used to assess hip function and clinical results. Plain radiographs were used to assess the correction of the deformity, healing of the osteotomy, and progression of degenerative arthritis. RESULTS: The mean Harris hip score increased from 68.8 points preoperatively to 91.3 points at the time of the most recent follow-up (p<0.0001). Sixteen patients (nineteen hips) had an excellent clinical result, and one patient (one hip) had a good result. Two patients (two hips) had a fair result, and one patient (two hips) had a poor result. Twenty-two of the twenty-four hips improved clinically. There was an average improvement of 27.6 degrees in the lateral center-edge angle of Wiberg (p<0.0001), an average improvement of 33.1 degrees in the anterior center-edge angle of Lequesne and de Seze (p<0.0001), and an average improvement of 16.5 degrees in the acetabular roof obliquity (p<0.0001). The hip center was translated medially an average of 6.3 mm (p=0.0003). The T?nnis osteoarthritis grade was unchanged in twenty hips, progressed one grade in three hips, and progressed two grades in one hip. There were three major technical complications. At the time of the most recent follow-up, none of the hips had required total hip arthroplasty. CONCLUSIONS: The combination of acetabular dysplasia and proximal femoral deformities presents a complex reconstructive problem. The range of motion and radiographic assessment of the hip are major factors in the selection of patients for surgery. In selected patients, the periacetabular osteotomy combined with concurrent femoral procedures, when indicated, can provide comprehensive deformity correction and improved hip function.     

Long-term results of intertrochanteric varus osteotomy for dysplastic osteoarthritis of the hip

The beneficial role of intertrochanteric varus or valgus osteotomy in the treatment of hip osteoarthrosis has been recognised since the 1920s. Even today, it has an important role to delay the need for hip replacement in younger patients. The purpose of this study was to evaluate the long-term results of intertrochanteric varus osteotomy for dysplastic osteoarthritis of the hip. Between 1980 and 1995, 52 hips with dysplastic osteoarthritis underwent an intertrochanteric varus osteotomy. All patients could be followed up after 17.8 years. Radiographic assessment included centre-edge (CE) angle of Wiberg and collodiaphyseal (CCD) angle. Dysplastic hip dislocation was classified according to Crowe. Osteoarthritis was graded according to Tönnis. Preoperative osteoarthritis was Tonnis grade 1 in 19 hips, grade 2 in 28 and grade 3 in five. Complications were also documented. Clinical evaluation included score according to Merle d’Aubigné, Harris Hip Score and range of motion. Six of 52 patients underwent total hip replacement (THR) within five years after intertrochanteric osteotomy. In these cases, preoperative osteoarthritis was grade 3 in four cases and grade 2 in one case according to Tönnis. Twenty-five of 52 patients underwent THR after an interval of five to ten years after intertrochanteric osteotomy. In these cases, preoperative osteoarthritis was grade 3 in one case and grade 2 in 24 cases according to Tönnis. Sixteen of 52 patients underwent THR after an interval of ten to 15 years after intertrochanteric osteotomy. In these cases, preoperative osteoarthritis was grade 2 in four cases and grade 1 in 12 cases according to Tönnis. In five patients the hip was functioning well after a period longer than 15 years. In all these cases osteoarthritis was grade 1 according to Tönnis. In 40.4% of patients, THR was delayed longer than ten years. The osteotomy performed well at a mean time of 9.7 years after the procedure (range 3–21). Intertrochanteric varus osteotomy for dysplastic osteoarthritis of the hip should be considered in early or mild osteoarthritic changes of the hip. Good prognosis with delay of THR of more than ten years can be expected to exceed 40%, even when indications are less than optimum.     

Outcome of periacetabular osteotomy for the management of acetabular dysplasia: experience in an academic centre

Periacetabular osteotomy (PAO) is a very effective reconstructive procedure for treatment of acetabular dysplasia. An orthopaedic paediatric surgeon and a reconstructive hip arthroplasty surgeon performed this procedure together in the early phase of their learning curve and then performed it individually. The early clinical and radiographic results of 85 consecutive PAOs performed in this academic orthopaedic unit were reviewed. The mean Merle-d'Aubigné score increased from 12.4 preoperatively to 16 at follow-up. Pre-operatively 73 hips were anteverted and 12 were neutral or retroverted. The mean angle of Wiberg improved from 5 degrees to 21 degrees (p < 0.0001) in anteverted hips, and from 9 degrees to 30 degrees in neutral or retroverted hips. The mean angle of Lequesne and de Sèze improved from 6 degrees to 35 degrees (p < 0.0001) in anteverted hips, and in neutral or retroverted hips from 9 degrees to 30 degrees (p < 0.0001). The acetabular index improved from 26 degrees to 8 degrees (p < 0.0001) in anteverted hips, and from 21 degrees to 7 degrees (p < 0.0001) in neutral or retroverted hips. Over the 7 year period the blood loss and operative time improved from 2000 ml to 900 ml and 4 hours to 2 hours respectively. Four hips (four patients) required conversion to total hip replacement. The radiographic correction and improved clinical scores are similar to those in previous studies. This study shows a survival rate of 94% at 58 months following periacetabular osteotomy. The learning curve and the early results of this procedure performed in our academic unit are encouraging.     

Evaluation of a computerized measurement technique for joint alignment before and during periacetabular osteotomy.

Periacetabular osteotomy (PAO) is intended to treat a painful dysplastic hip. Manual radiological angle measurements are used to diagnose dysplasia and to define regions of insufficient femoral head coverage for planning PAO. No method has yet been described that recalculates radiological angles as the acetabular bone fragment is reoriented. In this study, we propose a technique for computationally measuring the radiological angles from a joint contact surface model segmented from CT-scan data. Using oblique image slices, we selected the lateral and medial edge of the acetabulum lunate to form a closed, continuous, 3D curve. The joint surface is generated by interpolating the curve, and the radiological angles are measured directly using the 3D surface. This technique was evaluated using CT data for both normal and dysplastic hips. Manual measurements made by three independent observers showed minor discrepancies between the manual observations and the computerized technique. Inter-observer error (mean difference +/- standard deviation) was 0.04 +/- 3.53 degrees for Observer 1; -0.46 +/- 3.13 degrees for Observer 2; and 0.42 +/- 2.73 degrees for Observer 3. The measurement error for the proposed computer method was -1.30 +/- 3.30 degrees . The computerized technique demonstrates sufficient accuracy compared to manual techniques, making it suitable for planning and intraoperative evaluation of radiological metrics for periacetabular osteotomy.     

髋臼周围截骨治疗成人髋关节发育不良

目的 探讨髋臼周围截骨治疗成人髋关节发育不良的手术适应证及疗效.方法 25例成人髋关节发育不良患者接受经改良Smith-Peterson人路的髋臼周围截骨术,女19例,男6例;年龄18～45岁,平均25.5岁.均为单侧发病,左侧14例,右侧11例.3例有既往手术史,2例Chari截骨术、1例Salter截骨术.髋关节骨关节炎T(o)nnis 0期13例、Ⅰ期9例、Ⅱ期3例.Shenton线不连续18例.髋臼外侧CE角4.57°±7.39°,前侧CE角0.95°±6.02°,髋臼顶倾斜角32.50°±5.96°,股骨头超出指数38.11%±5.70%,Harris髋关节评分(75.32±7.51)分.结果 全部患者随访2.0～7.5年,平均4.5年.3例髋关节骨关节炎T(o)nnis Ⅰ期者改善为0期,2例T(o)nnisⅡ期者改善为Ⅰ期,1例T(o)nnis Ⅰ期者进展为Ⅱ期.Shenton线不连续减少为10例.外侧CE角29.07°±5.81°,前侧CE角29.52°±4.51°,髋臼顶倾斜角19.17°±4.95°,股骨头超出指数24.20%±4.83%,Harris髋关节评分(84.88±4.88)分,与术前比较差异均有统计学意义.16例出现股外侧皮神经支配区感觉麻木,其中9例自行恢复,7例残留永久性麻木.1例出现髋关节周围Brooker Ⅰ型异位骨化.结论 经改良Smith-Peterson人路行髋臼周围截骨治疗成人髋关节发育不良可有效增加髋臼包容,改善关节功能,阻止髋臼周围硬化和囊性变,保持关节间隙,延缓骨关节炎进展.