CE Angle Research Articles

A comparative radiographic investigation of femoroacetabular impingement in young patients with and without hip pain

OBJECTIVE:To compare the existence of radiographic abnormalities in two groups of patients, those with and without hip pain.METHODS:A total 222 patients were evaluated between March 2007 and April 2009; 122 complained of groin pain, and 100 had no symptoms. The individuals in both groups underwent radiographic examinations of the hip using the following views: anteroposterior, Lequesne false profile, Dunn, Dunn 45°, and Ducroquet.RESULTS:A total of 1110 radiographs were evaluated. Female patients were prevalent in both groups (52% symptomatic, 58% asymptomatic). There were statistically significant differences between the groups in age (p<0.0001), weight (p = 0.002) and BMI (p = 0.006). The positive findings in the group with groin pain consisted of the presence of a bump on the femoral head in the anteroposterior view (p<0.0001) or in the Dunn 45° view (p = 0.008). The difference in the α angle in the anteroposterior, Dunn, Dunn 45°, and Ducroquet views for all of the cases studied was p<0.0001. The joint space measurement differed significantly between groups in the Lequesne view (p = 0.007). The Lequesne anteversion angle (ρ) and the femoral offset measurement also differed significantly (p = 0.005 and p = 0.0001, respectively).CONCLUSIONS:We conclude that the best views for diagnosing a femoroacetabular impingement are the anteroposterior pelvic orthostatic, the Dunn 45°, and the Ducroquet views. The following findings correlated with hip pain: a decrease in the femoral offset, an increase in the α angle, an increase in the Lequesne ρ angle, a decrease in the CE angle of Wiberg, a thinner articular space and the presence of a bump on the femoral head-neck transition.

Computational measurement of joint space width and structural parameters in normal hips

Joint space width (JSW) of hip joints on radiographs in normal population may vary by related factors, but previous investigations were insufficient due to limitations of sources of radiographs, inclusion of subjects with osteoarthritis, and manual measurement techniques. We investigated influential factors on JSW using semiautomatic computational software on pelvic radiographs in asymptomatic subjects without radiological osteoarthritic findings. Global and local JSW at the medial, middle, and lateral compartments, and the hip structural parameters were measured in asymptomatic, normal 150 cases (300 hips), using a customized computational software. Reliability of measurement in global and local JSWs was high with intraobserver reproducibility (intraclass correlation coefficient) ranging from 0.957 to 0.993 and interobserver reproducibility ranging from 0.925 to 0.985. There were significant differences among three local JSWs, with the largest JSW at the lateral compartment. Global and medial local JSWs were significantly larger in the right hip, and global, medial and middle local JSWs were significantly smaller in women. Global and local JSWs were inversely correlated with CE angle and positively correlated with horizontal distance of the head center, but not correlated with body mass index in men and women. They were positively correlated with age and inversely correlated with vertical distance of the head center only in men. There were interindividual variations of JSW in normal population, depending on sites of the weight-bearing area, side, gender, age, and hip structural parameters. For accurate diagnosis and assessment of hip osteoarthritis, consideration of those influential factors other than degenerative change is important.

Treatment of developmental dysplasia of the hip with periacetabular osteotomy.

Objective To report the preliminary results of treatment of developmental dysplasia of the hip (DDH) with periacetabular osteotomy. Methods From February 2002 to February 2008, 53 patients (55 hips) with DDH were treated with periacetabular osteotomy. 51 patients were females, 2 were males, with the average age of 25.5 years (ranged, 13 to 51 years). The hip pain period before surgery varied from 1 month to 6 years (mean 16 months). 6 patients had the history of hip surgery. The mean Wiberg CE angle was 3°(range, -20°to 15°). According to Tonnis osteoarthritis classification, there were 16 cases in grade Ⅰ, 1 in grade Ⅱ. 25 patients had Shenton's line broken. The ilioinguinal approach was used in former 13 cases. The modified Smith-Petersen approach was used in later 40 cases. Intertrachanteric varus osteotomy was done simultaneously in 6 cases. Results The mean follow-up period was 28 months (ranged, 12 to 60 months). Bone union was achieved in 3 months after surgery. The pain relieved in most of patients. The Har-ris hip score increased from 77.4 points (ranged, 68 to 87 points) preoperatively to 94.6 points (ranged, 70 to 100 points) post-operatively. The range of motion of the hip decreased 20°-60° after surgery. The mean CE angle increased to 29°(ranged, 20° to 50°) postoperatively. 5 patients had limp after surgery, mostly due to dysfunction of gluteus medius, and recovered after 6 months of exercises. 18 patients got lateral femoral cu-taneous nerve injury. Two patients suffered pelvic ring broken and healed without affecting on hip function.No complication such as infection, vascular injury, sciatic neve injury happened in this series. Conclusion Satisfactory results can be obtained through periacetabular osteotomy in young patients with DDH. Periac-etabular osteotomy can correct the acetabular deformity in multiplanar. No vascular impair in acetabular fragment. The stability of the pelvic can be reserved. Early rehabilitation is allowed after surgery. Key words: Hip dislocation; congenital; Osteotomy; Acetabulum

Acetabular morphometry and prevalence of hip dysplasia in the South Asian population

We carried out a cross-sectional study to measure the association of the seven acetabular parameters with pelvic morphometry and prevalence of hip dysplasia in our population. Convenience sampling was carried out and 250 consecutive patients who came to AKUH for intravenous pyelogram and had no complaints in the region of the hip joint were enrolled in the study. Post-micturition standardized plain antero-posterior pelvic radiographs of 250 asymptomatic adults (500 hip joints) was studied. There were 136 males (54.4%) and 114 females (45.6%). Mean age of our study population was 38 years (15–78 years). The average center edge angle was 35.5±6.6° standard deviation (SD), acetabular angle was 37.76±4.37°, depth to width ratio was 0.31±4.6°, roof obliquity was 10.6±6.2°, extrusion index was 0.1±5.8, lateral subluxation 8.9±2.7 mm, and peak to edge distance 17±3.98 mm. There was significant influence (p<0.05) of age in all angles except depth to width ratio. A total of seven hip joints (1.4%) were dysplastic with CE angle <25° while four of the seven hips were severely dysplastic with CE angle <20°. In the dysplastic group there was significant correlation (p<0.05) of CE angle with acetabular angle, depth to width ratio, extrusion index and peak to edge distance. Prevalence of hip dysplasia was found to be very low in our population. These results are consistent with the findings of studies carried out in other Asian countries.

Long-term Experience with Chiari's Osteotomy

Fifty-six years after the introduction of Chiari's pelvic osteotomy, we report the long-term function scores and radiographic grade of osteoarthritis in 66 patients with 80 pelvic osteotomies with a minimum followup time of 27 years (average, 32 years; range, 27-48 years). These 66 patients were those who could be contacted and who returned for a followup visit from among 450 patients operated between 1961 and 1981. Thirty-two hips (40%) in 28 patients had undergone a total joint arthroplasty after an average 26 years (range, 13-41 years). Forty-eight hips in 41 patients (60%) were not replaced, their Harris hip score being a median of 82 points (range, 37-100 points). For the 22 patients for whom we had complete radiographs the average preoperative CE angle was 11.6 degrees, 48.6 degrees (range, 31 degrees-82.8 degrees) immediately postoperatively, and 41.6 degrees (range, 13.7 degrees-90 degrees) at last followup . Despite a functional hip score in most patients retaining their native hip, the degree of osteoarthritis progressed at last followup. We observed a similar mean age at the time of osteotomy in patients converted to total hip arthroplasty and those retaining their native hip. Age at time of surgery was inversely correlated (r = -0.78) with the interval between the osteotomy and THA. In this select patient group we found good functional outcome in patients who underwent Chiari pelvic osteotomy, with a conversion rate of 40% to total hip arthroplasty a mean of 32 years after the procedure. Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.

Triple pelvic osteotomy in the treatment of Legg-Calve-Perthes disease

This article presents the results of Legg-Calve-Perthes (LCP) disease treatment using triple pelvic osteotomy. Thirty patients were analysed. The conditions for inclusion in the study were complete medical documentation and follow-up until the disease was resolved. Postoperatively, no patients were immobilised. Rehabilitation was initiated early in all patients, and full weight bearing was allowed after ten weeks. With this method, an increase of the CE angle of 17.43 +/- 4.020 degrees was achieved. Containment was increased from an initial 6.67% to 53.33% of patients at the final check-up. Similar improvement was achieved by using Herring classification of the damage; preoperatively most hips belonged to group C, and postoperatively to group A. Postoperatively, functional results were also considerably improved. The authors recommend triple pelvic osteotomy as the method of choice in the treatment of severe cases of LCP disease.

Vascularised iliac graft as a method of acetabular augmentation in subluxed hip in adolescents

This article presents the clinical experience of patients with a dysplasic subluxated hip treated with the same procedure involving a vascularised graft of iliac crest by sartorius muscle. This study was performed in three different centres, in two different countries, and in 31 patients with 37 hips (9 bilateral). All patients were clinically evaluated according to the Merle d Aubigne scale and radiological measuring of acetabular coverage, Sharp angle, and CE angle. Walking ability preoperatively was 4.87 and postoperatively 5.12, which was not statistically significant. Preoperative inclination acetabular angle was 59.0 degrees +/- 6.23 and postoperatively 37.5 degrees +/- 6.08 (P < 0.00001). Preoperative CE angle was -2.03 degrees +/- 13.5 and postoperatively was 41.0 degrees +/- 12.3 ( P < 0.00001). Index head acetabulum had a preoperative coverage of 48.3% +/- 13.0 and postoperatively 100.8% +/- 19.5. The head sphericity did not show any statistically significant difference in relation to the results. The results obtained were satisfactory from every point of view, making this the procedure of choice in the armamentarium to delay the need for a total joint as treatment of early osteoarthritis in young adults.

Triple pelvic osteotomy in the treatment of hip dysplasia

Insufficient femoral head coverage is found in a variety of diseases, with acetabular dysplasia as the most frequent disorder and triple pelvic osteotomy as the most recently introduced surgical treatment. This study analyses pre- and postoperative pathoanatomic characteristics of triple in comparison to Salter and Chiari osteotomies, with a logistic regression analysis of outcome predictor and effect explanator factors in relation to the chosen type of operation. The study involved 136 adolescents treated with Salter and Chiari osteotomies or a triple pelvic osteotomy at the Institute of Orthopaedic Surgery "Banjica" in Belgrade. The patients were between 10-20 years old at the time of operation. We collected and analyzed data from all the patients: illness history, operative parameters, preoperative and postoperative pathoanatomic data. The data was statistically processed using the statistical software SPSS, defining standard descriptive values, and by using the appropriate tests of analytic statistics: t-test for dependent and independent variables, chi2-test, Fisher's exact test, Wilcoxon's test, parameter correlation, one-way ANOVA, multi-factorial ANOVA and logistic regression, according to the type of the analyzed data and the conditions under which the statistical methods were applied. The average CE angle after triple pelvic osteotomy was 43.5 degrees, more improved than after the Salter osteotomy (33.0 degrees) and Chiari osteotomy (31.4 degrees) (F = 16.822; p < 0.01). Postoperative spherical congruence was also more frequent after the triple osteotomy than after the other two types of operations, and with a high significance. Preoperative painful discomfort was found to be a valid predictor of indications for the triple osteotomy over both Chiari and Salter osteotomies. The valid explanators of effect for the triple osteotomy are: postoperative joint congruence (compared to the Chiari osteotomy) and increase in joint coverage (compared to Salter osteotomy). Triple pelvic osteotomy is the method of choice in the management of acetabular dysplasia and other disturbances of hip joint containment in adolescent age.

The effects of impingement and dysplasia on stress distributions in the hip joint during sitting and walking: A finite element analysis

Soft tissue damage has been observed in hip joints with pathological geometries. Our primary goal was to study the relationship between morphological variations of the bony components of the hip and resultant stresses within the soft tissues of the joint during routine daily activities. The secondary goal was to find the range of morphological parameters in which stresses are minimized. Computational models of normal and pathological joints were developed based on variations of morphological parameters of the femoral head (Alpha angle) and acetabulum (CE angle). The Alpha angle was varied between 40 degrees (normal joint) and 80 degrees (cam joint). The CE angle was varied between 0 degrees (dysplastic joint) and 40 degrees (pincer joint). Dynamic loads and motions for walking and standing to sitting were applied to all joint configurations. Contact pressures and stresses were calculated and crosscompared to evaluate the influence of morphology. The stresses in the soft tissues depended strongly on the head and acetabular geometry. For the dysplastic joint, walking produced high acetabular rim stresses. Conversely, for impinging joints, standing-to-sitting activities that involved extensive motion were critical, inducing excessive distortion and shearing of the tissue-bone interface. Zones with high von Mises stresses corresponded with clinically observed damage zones in the acetabular cartilage and labrum. Hip joint morphological parameters that minimized were 20 degrees <or= CE <or= 30 degrees and alpha <or= 50 degrees .

Evaluation of the ipsilateral knee more than 40 years after successful closed reduction of DDH

We asked whether the ipsilateral knee of patients treated by closed reduction for developmental hip dislocation (DDH) is affected by osteoarthritis (OA) more than 40 years later. In total, 61 patients (71 hips) with the diagnosis of DDH were included in the study. The average age at the time of closed reduction was 17.9 months. The follow-up after closed reduction averaged 44.4 years. We determined the following parameters on radiographs, taken in the standing position: minimal joint space width in the medial and lateral compartments of the knee, minimal joint space width of the hip joint, radiological signs of osteoarthritis of the knee and the hip joints (Kellgren and Lawrence), knee alignment, acetabular roof obliquity (AC angle), depth of the acetabulum (ACM angle) and center-edge angle (CE angle) according to Wiberg. All radiographs were measured twice manually with ruler and goniometer by two independent investigators. Interobserver and intraobserver reliability (test-retest) was calculated for all parameters. We observed that patients with bilateral DDH had significantly more joint space narrowing in the medial compartment of the knee joints than those with unilateral DDH. The length of follow-up correlated with radiological signs of OA in the hip, but not in the knee. We found a significant difference in medial compartment joint space narrowing between patients with unilateral DDH and those with bilateral DDH. The Kellgren-Lawrence classification, however, showed no significant differences between uni- and bilateral DDH. The knee alignment was always at the threshold of physiological values.

Growth disorders of the acetabular roof after acetabuloplasty in congenital hip dysplasia

The aim of this long-term study was to evaluate whether the Lance acetabuloplasty for congenital dysplasia of the hip causes a growth disturbance of the acetabular roof during or after puberty. 71 hips of 58 patients were followed clinically and radiologically over a maximum time of 16 years after the operative procedure of a Lance acetabuloplasty. The average age of the patients at the time of operation was 2.8 years (1-6 years). In order to assess the growth of the acetabulum in the early and long-term postoperative phase quantitative parameters (acetabular index of Hilgenreiner, CE angle of Wiberg, ACM angle of Idelberger) as well as qualitative parameters (disturbance of the ossification of the acetabulum and the femoral head) were determined in standardized X-rays of the pelvis, done routinely 6 months, 3 years, 5 years, 8 years and at an average of 11 years as the last follow-up examination after the operation. The assessment of these metrical parameters were carried out in accordance to the classification of the study-group "hip dysplasia" of the DGOT (normal--slight pathological--serious pathological) respecting the different age-groups and degrees of dysplasia. Although in the early postoperative phase the acetabular roof showed a positive development (65% of the CE angles could be considered normal 3 years after operation), the further growth of the acetabulum was disturbed in the period of puberty (8 years after operation only 33% of the CE angles could be considered normal, 51% were extremely pathological). And also in the last X-ray control after an average follow-up time of 11 years a significant retardation of the acetabular roof was seen in 51% of all cases. The Lance acetabuloplasty seems to damage the Ossa acetabuli, which are as centers of ossification the essential anatomic structures for the growth of the acetabular rim in adolescence. Other procedures such as the Salter osteotomy are to be preferred for the therapy of hip dysplasia.

Follow-up results of adduction-derotation osteotomies in hip dysplasia

The first part of the investigation was concerned with the evaluation of radiographs of 64 children in whom 97 intertrochanteric adduction-derotation osteotomies were performed when the patients were between two and ten years old. Prior to surgery, immediately thereafter and two and six years later, the CCD, AC, ACM and CE angles of all the patients were measured on plain pelvic radiographs. On the radiographs made after six years 70% of the CCD angles were normal, while pathologic coxa valga was found in 15% and coxa vara also in 15%. The AC angle was normal in 32% , the ACM angle in 31%; however, these normal groups were only 76% identical. The CE angle had normalized in 32% of the cases. The second part of the paper deals with clinical and radiological follow-up findings in 46 of these patients in whom 64 hips had been treated. The follow-up period varied between six and 13 years. On clinical examination the result was found to be satisfactory in 59% and unsatisfactory in 41%. A comparison with radiological-anatomical findings showed that in 32% of the radiologically satisfactory cases there were some considerable functional limitations and subjective complaints. The author's own results are compared with communications in the literature, in particular with the Swiss collective statistics published by Jani (1973) and Reichelt and Hansen's publication (1975). To provide the reader with a survey of the number of cases, age at operation and periods of observation quoted by different authors, these data are presented synoptically in tabular form. Another table lists the criteria investigated by the individual authors (AC, ACM, CE, CCD and AT angles). The discussion is completed with conclusions relevant to clinical practice.

Analyses of survival time of joints with dysplastic arthrosis after intertrochanteric femoral osteotomy

Survivorship analysis was performed up to 13 years after intertrochanteric femoral osteotomies in 136 dysplastic hip joints with osteoarthritis. Varus-valgus and rotational osteotomies were evaluated. The criterium limiting survival was the recurrence of pain postoperatively. Joints with severely pathological Sharp Angles (> 48 degrees) showed a diminution within 10 years to 50%. Moderately pathological joints (< 49 degrees) needed 13 years to diminish to 50%. 3 groups of the CE angle showed a similar picture with somewhat more difference between the groups, but not statistically significant during this time. This was different when evaluating the 3 grades of arthrosis. Joints with grade 1 were free of pain after 13 years in only 51.2%, joints of grade 2 already after 10 years in only 37% (p < 0.05). The final values of grade 3 joints were found after only 5 years. This demonstrates that varus osteotomy is only of limited value in dysplastic joints with osteoarthritis. Operations correcting the acetabulum have to be compared. In 21 patients rotational osteotomies to correct external rotation contracture had a marked effect on pain in 90.4%, valgus osteotomies with rotation in 75%, varusosteotomies with rotation in 65%. Without rotation a marked reduction of pain was found in varus osteotomy in 61.6% and in valgus osteotomy in only 55%. So far, patients with diminished anteversion of the femur were not separated and treated specially. But diminished anteversion of the femur and/or acetabulum leads to osteoarthritis too.

Biomechanical parameters for planning Chiari's pelvic osteotomy

A Chiari osteotomy was performed in a macerated female pelvis specimen and the medialization of the distal pelvic segment bearing the hip joint was simulated within a range from 0-2.5 cm. In relation to the medialization different biomechanical hip-parameters were measured as well from the specimen as from the x-ray. For practical purpose the Wiberg CE angle towards the edge of the original acetabulum and the CE' angle towards the edge of the acetabular shelf are important parameters for preoperative calculation of the required amount of medialization.

Results of the treatment of congenital hip dislocation using Salter's open repositioning and pelvic osteotomy

In this paper the results of Salter's innominate osteotomy combined with an open reduction are shown on the basis of radiographic and clinical investigations. From 1969-1976 43 hips up to the age of 3.11 years had been treated after Salter's method. At the follow-up 65.6% of the hips were found to have normal or slightly pathological AC angles. 63.4% of the hips show good and fair results concerning the ACM angle. The results of the CE angle and the 'hip value' are disappointing: only just 34.1% of the hips can be considered good or fair. This is a consequence of the high rate of preoperative avascular necrosis on the one hand, on the other hand it is based on the fact that most of the cases had had a previous non-operative or operative treatment.

Vascularised iliac graft as a method of acetabular augmentation in subluxed hip in adolescents

This article presents the clinical experience of patients with a dysplasic subluxated hip treated with the same procedure involving a vascularised graft of iliac crest by sartorius muscle. This study was performed in three different centres, in two different countries, and in 31 patients with 37 hips (9 bilateral). All patients were clinically evaluated according to the Merle d Aubigne scale and radiological measuring of acetabular coverage, Sharp angle, and CE angle. Walking ability preoperatively was 4.87 and postoperatively 5.12, which was not statistically significant. Preoperative inclination acetabular angle was 59.0 degrees +/- 6.23 and postoperatively 37.5 degrees +/- 6.08 (P < 0.00001). Preoperative CE angle was -2.03 degrees +/- 13.5 and postoperatively was 41.0 degrees +/- 12.3 ( P < 0.00001). Index head acetabulum had a preoperative coverage of 48.3% +/- 13.0 and postoperatively 100.8% +/- 19.5. The head sphericity did not show any statistically significant difference in relation to the results. The results obtained were satisfactory from every point of view, making this the procedure of choice in the armamentarium to delay the need for a total joint as treatment of early osteoarthritis in young adults.

Multiple drillings of the acetabular fossa induce early joint remodeling after rotational acetabular osteotomy for hip dysplasia

We previously observed medial and/or lateral expansion of the subchondral bone in the acetabulum 3 years postoperatively in two out of three cases in which rotational acetabular osteotomy (RAO) was performed. Then we performed multiple drillings at the acetabular fossa in order to induce expansion of the medial subchondral bone in the acetabulum. The purpose of this study is to evaluate the effect of multiple drillings on early joint remodeling after RAO. Twenty-one women (21 joints) who had undergone RAO with multiple drillings at acetabular fossa (group D) were included. As a control group, 12 women (14 joints) without drillings in RAO procedure were observed (group C). The center-edge angle (CE angle), acetabular roof obliquity (AC angle), head lateralization index (HLI), and the angle between medial and lateral edge of acetabular roof (LOM angle) were measured on the radiographs preoperatively, at 1 month, 2 years postoperatively, and at the last follow-up. As regards the mean CE angle, AC angle, and HLI, there was no significant difference between the two groups. The mean LOM angle at 2 years and the last follow-up demonstrated significant difference between the two groups. Biomechanical and anatomical changes after RAO cause increasing stress to the medial side of the acetabulum. Moreover, bone marrow-stimulating procedure at acetabular fossa might be beneficial to develop early joint remodeling affected by bone marrow derived cells such as mesenchymal stem cells.

Is varus osteotomy necessary in one-stage treatment of developmental dislocation of the hip in older children?

Innominate osteotomy, varisation-derotation osteotomy, and shortening osteotomy are the most common surgical procedures used to achieve pelvifemoral realignment in the treatment of children over three years of age with developmental hip dislocation. It is well known that varus osteotomy can improve the acetabular index but it does have some disadvantages. The aim of this study was to discuss the results obtained with patients treated only with Salter osteotomy, derotation osteotomy, and shortening, without varus osteotomy, and to evaluate the need for varisation on the basis of these results. Between 1996 and 2001, twenty-four hips, sixteen unilateral and four bilateral, of a total of twenty patients treated with this method and available for final controls were evaluated. The study included sixteen female and four male patients with a mean age of 4 years 2 months (ranging between 2 years 10 months and 8 years). The mean follow-up period was determined as 6.57 years (range 5-10 years). McKay's clinical criteria, Sever's radiological criteria, and the evaluation system modified by Trevor et al. were used for evaluation of the results. Based on McKay's clinical criteria, eighteen hips (75%) were classified as type I, four hips (16%) as type II, and two hips (9%) as type III. According to Sever's radiological criteria, thirteen hips (54%) were graded as grade I, nine hips (37.5%) as grade II, and two (8.5%) as grade III. According to the modified evaluation system of Trevor et al. the results were categorized as excellent in thirteen hips, good in nine hips, and moderate in two hips. Pre-operative mean acetabular index was measured as 37.3 degrees (28 degrees -50 degrees ) and early post-operative mean acetabular index as 26 degrees (18 degrees -38 degrees ). In the final radiological examination the mean acetabular index was measured as 18.3 degrees and the mean CE angle as 30.1 degrees (15 degrees -38 degrees ). Avascular necrosis affecting the results developed in five hips. It is concluded that in older children with developmental dislocation of the hip (DDH) treated with one-stage combined surgical intervention, adequately stable concentric reduction can be achieved without varisation and that varus osteotomy is not always necessary.

Is bladder exstrophy a risk factor for hip arthrosis?

Purpose Although the management of patients born with bladder exstrophy (BE) may include pelvic osteotomies, nothing is known about the long-term natural history of the pelvic deformity. We assessed the orthopaedic outcome in adult patients. Material and methods 22 BE patients treated with ureterosigmoidostomies between 1945 and 1968 were evaluated clinically using Harris hip scores and radiographically using Tonnis classification. Results The mean age of the patients was 50 ±12 years. Clinical evaluation revealed an excellent outcome resulting in 91-100 points of the Harris Hip Score in 80 % of the left and in 76 % of the right hips. Good outcomes of 81-90 points were found in 10 % of the left hips and in 14 % of the right hips, while fair outcomes of 71-80 points were found in the remaining 10 % of both hips. No patient scored less than 70 points. 16% of the patients were classified as Tonnis grade 0, 63% as grade 1 and 21% were classified as grade 2. No patient was classified as Tonnis grade 3. The mean pubic symphysis diastasis was 87 mm (range: 30-152 mm). The mean CE angle on the right hand side varied from 24-44° (mean CE angle 35°) and on the left from 24-50° (mean CE angle 36°). No instability of the symphysis nor the sacroiliac joint was detected. Conclusions We concluded that patients with bladder exstrophy and an untreated pelvic deformity are not at risk of a higher incidence or earlier onset of hip arthrosis than normals. Long-term follow-up reveals no pelvic instability.

The role of triple pelvic osteotomy in therapy of residual hip dysplasia and sequel of AVN: long-term experience

Triple pelvic osteotomy was performed for sequel of DDH including AVN between 1981 and 2002 for 329 patients (351 hips, 280 females, 49 males, average age at surgery 16.5 years, range 9-41 years, follow-up 4-25 years). A small modification of Steel's technique consisting of strictly subperiostal resection of segment from both pubic and ischial bone was used. Average gain of lengthening extremity was 1.8 cm. The average CE angle was improved from 7.8 to 35.5 degrees. Clinical results were evaluated according to Merle d'Aubigne and reflected to the preoperative clinical and radiological findings. There were 146 hip joints in 128 patients (76%) with excellent results in the group of congruent hips without arthrosis. In 182 hips in 178 patients with hip joints with some deformity, limited ROM and decentration, 40% were excellent, 32% good, 23% fair and 5% unsatisfactory results were achieved. The group of decentrated hip joints in young adults in incongruency, limited ROM and sometimes severe arthrosis consisted of 23 monolateral surgeries with 39% unsatisfactory, 39% fair and 22% good results, respectively. No major neurovascular complications were seen. Non-unions were recorded in 19 patients (5.4%), including 2 triple and 2 double non-unions. Based on our long-term experience, we can conclude that triple pelvic osteotomy according to Steel in our modification is a safe method and gives regularly excellent or good results for correction of clinical and radiographic appearance of acetabular dysplasia when there is a proper indication.