The December 2024 Children’s orthopaedics Roundup. 360. looks at: Establishing best practice for managing idiopathic toe walking in children: a UK consensus; Long-term outcomes of below-elbow casting in paediatric diaphyseal forearm fractures; Residual dysplasia risk persists in developmental dysplasia of the hip patients after Pavlik harness treatment; 3D printing in paediatricorthopaedics: enhancing surgical efficiency and patient outcomes; Pavlik harness treatment for hip dysplasia does not delay motor skill development in children; High prevalence of hip dysplasia found in adolescents with idiopathic scoliosis on routine spine radiographs; Minifragment plates as effective growth modulation for ulnar deformities of the distal radius in children; Long-term success of Chiari pelvic osteotomy in preserving hip function: 30-year follow-up study

Introduction. Acetabular dysplasia is a common cause of osteoarthritis of the hip. Chiari pelvic osteotomy enables medialization of the center of the femoral head and improvement of coverage over the femoral head for hip dysplasia and prevents or delays progression of degenerative arthritis. We reviewed 104 patients after this augmentation procedure. Patients and methods. Between 1989 and 2000, 167 patients with developmental dysplasia of the hip had undergone the surgery at university hospital. Among them, 104 patients were able to be traced after surgery for more than 10 years. The mean follow-up period was 15.5 years. There were 96 women and 8 men with an average age of 34.3 years at surgery. The average angle of osteotomy was 6.6 degree craniad to the horizontal plane. Ratio of migration of the distal pelvis was 42%. Results. 8 hips were replaced by prosthesis. Setting total hip arthroplasty as an end point, 10-year, 15-year and 20-year survival rate was 99.0, 92.3 and 70.0% respectively. Patients with minimal grade of osteoarthritis at the time of osteotomy preserved 5.4 mm joint space on plain radiographs of last time follow-up. Patients with moderate or severe grade of osteoarthritis at the time of surgery had only 2.5 mm joint space at last. All patients with minimal grade of osteoarthritis could avoid total hip arthroplasty. Conclusion. Chiari pelvic osteotomy can prevent progression of degenerative arthritis in patients with minimal grade of osteoarthritis for more than 15 years

We present the results of Chiari pelvic osteotomy in the treatment of adolescent hip incongruence, with special interest in identifying possibilities, limitations and complications. In a series of 86 patients treated by Chiari pelvic osteotomy (13 operated bilateraly) at the Institute for Orthopaedic Surgery “Banjica” with a follow-up period more than 48 months, we analyzed the relation of Chiari-specific parameters collected from postoperative radiograms (osteotomy angle and heigth, and displacement index) to various preoperative and postoperative parameters (Sharp acetabular angle, Wiberg CE angle, Heyman and Herndon femoral head extrusion index (FHEI), Acetabular depth ratio (ADR), Shenton-Menard arch integrity, limb length discrepancy, gait quality) and functional result according to HHS and McKay scoring systems. We found highly significant improvements of Sharp angle (from 47.2±6.1° preoperatively to 38.6±7.8° finally, p<0.01), Wiberg CE angle (from 10.2±16.8° to 38.9±14.6°, p<0.01) and FHEI (from from 53.4±21% to 1.9±70.7%, p<0.01). In adition, HHS was also improved from 76±15.1 to final 87.9±9.4, p<0.01). We also assessed the satisfaction of both patients (index 4.2 out of 5) and surgeons (index 3.7 out of 5). Chiari pelvic osteotomy is useful surgical procedure in the selected cases of adolescent hip incongruence with disturbance of hip centering and coverage

The August 2012 Children’s orthopaedics Roundup³⁶⁰ looks at: whether 3D-CT gives a better idea of coverage than plain radiographs; forearm fractures after trampolining accidents; forearm fractures and the Rush pin; the fractured distal radius; elastic stable intramedullary nailing for long-bone fractures; aponeurotic recession for the equinus foot; the torn medial patellofemoral ligament and the adductor tubercle; slipped capital femoral epiphysis; paediatric wrist arthroscopy; and Pirani scores and clubfoot.

In order to manage painful subluxation/dislocation secondary to cerebral palsy, 12 hips in 11 patients received combined femoral and Chiari pelvic osteotomies with additional soft tissues releases at an average age of 14.1 (9.1-17.8) years. Pain relief, improvement in the arc of movement, sitting posture and ease of perineal care was recorded in all, and these features have been maintained at an average follow-up of 13.1 (8-17.5) years. The improvement of general mobility was marginal, but those who were community walkers benefited the most. Pre-operative radiological measurements have been modified post-operatively to use lateral margin of the neo-acetabulum produced by the pelvic osteotomy. The radiological migration index improved from a mean of 80.6% to 13.7% [p<0.0001]. The mean changes in CE angle and Sharp's angle were 72° (range 56°- 87°) [p<0.0001] and 12.3° (range 9°- 15.6°) [p< 0.0001] respectively. Radiological evidence of progressive arthritic change was seen in only one hip, in which only a partial reduction had been achieved, and there was early joint space narrowing in another. Heterotopic ossification was observed in one patient with athetoid quadriplegia who remained pain free. In seven hips the lateral Kawamura approach, elevating the greater trochanter, provided exposure for both osteotomies and allowed the construction of a dome-shaped iliac osteotomy, while protecting the sciatic nerve. This combined procedure provides a stable hip with sustained pain relief for the adolescent and young adult presenting with pain

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

To analyze the long term results of a third generation ceramic on ceramic bearing in cementless total hip arthroplasty (THA), we reviewed the clinical and radiological results of 100 consecutive THAs performed in 86 patients (68 females, 80 hips; 18 males, 20 hips) between 1996 and 1998. The average age at operation was 55 years with a range of 26 to 73 years. The diagnoses were osteoarthritis in 83 hips, osteonecrosis in 10 hips and rheumatoid arthritis in 7 hips. The articulation was composed of a hemispherical titanium porous bead-coated cup (AnCA), a Biolox Forte alumina ceramic cup liner and a ball with a diameter of 28-mm. The modular ceramic liner was fixed directly to the metal cup without polyethylene sandwich or metal rim. A press-fit technique of 1 mm under-reaming without screws was used for cup fixation. The ceramic head was fixed to a 12/14 taper cone of a modular neck which allowed changes in neck-shaft angle, anteversion, and offset. All operations were performed via a posterolateral approach under general anesthesia. To measure the cup orientation, an ellipse was fitted to the acetabular component rim on the early postoperative AP radiographs using computer software. The average cup inclination and anteversion in the radiographic definition were 41 (range 28 to 63) and 17 (range 3 to 34) degrees, respectively. 22 cups were outside the Lewinnek safe zone. All patients were radiographically evaluated in term of implant stability at two years using Engh’s criteria. All of the acetabular components radiologically were judged to be bone-ingrown stable at two years except one cup. 98 stems were judged to be bone-ingrown stable and the remaining two stems were judged to be fibrous stable at two years. After two years, all patients except for two were followed up clinically and radiologically for at least 10 years or until revision or death. One unstable cup was revised at 2.5 years. This case had a previous Chiari’s pelvic osteotomy and insufficient press-fit of the cup was assumed to have led to loosening. One of the two fibrous stable stems was revised at six years due to aseptic loosening. One rheumatoid arthritis hip with stable bone ingrown fixation developed late infection at six years and was revised. One stable cup showed chipping of the acetabular liner at 8 years and required revision. The orientation of this cup was 55 degrees of inclination and 17 degrees of anteversion and the high inclination was thought to be related to the ceramic liner chipping. The remaining hips showed no osteolysis or loosening at the final follow-up. There were no squeaking hips. The 10-year survivorships with the endpoint of mechanical loosening or revision were 96.7% and 95.6%, respectively. We conclude that the third generation ceramic on ceramic hip bearing without polyethylene sandwich provided long term stability and eliminated periprosthetic osteolysis

Implantation of a large-diameter femoral head prosthesis with a metal-on-metal bearing surface reduces the risk of dislocation, increases the range of movement, minimises the risk of impingement and, in theory, results in little wear.

Between February 2004 and March 2007 we implanted 100 consecutive total hip replacements with a metal-on-metal bearing and a large femoral head into 92 patients. There were 51 men and 41 women with a mean age of 50 years (18 to 70) at the time of surgery.

Outcome was assessed using the Western Ontario McMaster University osteoarthritis index and the Harris hip score as well as the Devane activity score. These all improved significantly (p < 0.0001). At the last follow-up there were no cases of dislocation, no impingement, a good range of movement and no osteolysis, but seven revisions, two for infection and five for aseptic loosening. The probability of groin pain increased if the other acetabular component inclination exceeded 50° (p = 0.0007). At 4.8 years of follow-up, the projected survival of the Durom acetabular component, with revision for any reason, was 92.4% (sd 2.8) (95% confidence interval 89.6 to 95.2).

The design of the component made it difficult both to orientate and seat, which when combined with a poor porous coating, produced unpredictable fixation and a low survival at five years.

In order to treat painful subluxation or dislocation secondary to cerebral palsy, 11 patients (12 hips) underwent combined femoral and Chiari pelvic osteotomies with additional soft-tissue releases at a mean age of 14.1 years (9.1 to 17.8). Relief of pain, improvement in movement of the hip, and in sitting posture, and ease of perineal care were recorded in all, and were maintained at a mean follow-up of 13.1 years (8 to 17.5). The improvement in general mobility was marginal, but those who were able to walk benefited the most. The radiological measurements made before operation were modified afterwards to use the lateral margin of the neoacetabulum produced by the pelvic osteotomy. The radiological migration index improved from a mean of 80.6% (61% to 100%) to 13.7% (0% to 33%) (p < 0.0001). The mean changes in centre edge angle and Sharp’s angle were 72° (56° to 87°; p < 0.0001) and 12.3° (9° to 15.6°; p < 0.0001), respectively. Radiological evidence of progressive arthritic change was seen in one hip, in which only a partial reduction had been achieved, and there was early narrowing of the joint space in another. Painless heterotopic ossification was observed in one patient with athetoid quadriplegia. In seven hips the lateral Kawamura approach, elevating the greater trochanter, provided exposure for both osteotomies and allowed the construction of a dome-shaped iliac osteotomy, while protecting the sciatic nerve

Subluxation of the hip is common in patients with intermediate spinal muscular atrophy. This retrospective study aimed to investigate the influence of surgery on pain and function, as well as the natural history of subluxed hips which were treated conservatively. Thirty patients were assessed clinically and radiologically. Of the nine who underwent surgery only one reported satisfaction and four had recurrent subluxation. Of the 21 patients who had no surgery, 18 had subluxation at the latest follow-up, but only one reported pain in the hip. We conclude that surgery for subluxation of the hip in these patients is not justified.

Aims: Purpose of the study was comparison of the results of different pelvic osteotomies (Chiari, Salter, triple osteotomy) in the treatment of consequences of DDH in adolescents. Methods: Analysis included 124 patients treated operatively for consequences of DDH in adolescence. The average age of patients was 13.6. All patients were divided into four groups according to the operative technique used (isolated Salter pelvic osteotomy, Salter osteotomy and corrective femoral osteotomy, Chiari pelvic osteotomy and triple pelvic osteotomy). Preoperative and postoperative values of CE angle of Wiberg, acetabulum-head ratio of Heyman-Herndon and Harris hip score were analysed. Congruency was assessed according to Stulberg classiþcation before and after operative treatment. Results: Signiþcant improvement was achieved in all groups. The greatest improvement was noticed in the group of triple pelvic osteotomies. Comparison between groups has shown that signiþcantly better results were achieved with triple pelvic osteotomy. Conclusions: In dysplastic hips without signs of damage of the femoral head and neck we suggest triple pelvic osteotomy in patients older than 10. If deformity of femoral head exists, additional radiographic examination should be made to assess the possibility of achieving spherical congruency of the hip operatively. If this can be done we suggest performing triple or Salter osteotomy with corrective osteotomy of femur. Chiari pelvic osteotomy should be reserved for patients older than 10 in whom spherical congruency can not be achieved or if degenerative changes of the hip already exist

We present the mid- to long-term results of the Chiari pelvic osteotomy for dysplastic hips. We followed 135 hips in 129 patients, with a mean age at the time of surgery of 24 years, for a mean of 16.2 years. We used the anterior iliofemoral approach without trochanteric osteotomy in the initial 31 hips. Thereafter, we used transtrochanteric approaches in an attempt to ensure that the osteotomy was at the most appropriate level, and to advance the high-riding greater trochanter distally. The next 79 hips therefore underwent a posterolateral approach and the most recent 25 hips an Ollier lateral U approach. The clinical result was excellent or good in 103 hips (77%). The outcome in 104 hips in which we used a transtrochanteric approach was superior, the osteotomy level was more appropriate and a Trendelenburg gait less common than in 31 hips in which we used an anterior approach. We therefore recommend the use of a transtrochanteric approach in order to ensure that the osteotomy is at an appropriate level and in order to achieve effective distal advancement of the high-riding greater trochanter

The senior author performed Kawamura Dome Chiari pelvic osteotomy on four patients with hip dysplasia, an incongruent hip joint and a weakly developed posterior wall that caused posterior instability. Although follow-up has not been long term, the uncomplicated postoperative course and improved hip stability of all four patients suggest that this operation offers a solution to a selected group of patients

Using a lateral approach during which the greater trochanter is excised, we performed domical pelvic osteotomy (modified chiari’s prpcedure) different from the original Chiarifs procedure. In a series of 176 modified Chiari pelvic osteotomies in 175 patients over 40 years old of the advanced coxarthrosis with acetabular dysplasia , in whom the postoperative courses were followed for more than 5 years (average, 6.9 years). JOA hip scores were improved in pain from 15.6 to 34.2 points and a total JOA score was improved from 55.7 to 76.5 points ,almost satisfactory results were obtained in 72.8% . In particular, markedly satisfactory results were obtained with respect to the improvement of pain in 84%. Radiographically, the coverage of the femoral head was markedly improved .The joint space was more dilated in 55% compared to that before surgery., however, the stage of coxarthrosis was more advanced in 18patients . In addition, the pathologic conditions of coxarthrosis had clinically deteriorated in 11 patients, resulting in treatment by total hip arthroplasty. As a result, there were more satisfactory results obtained, even in patients with advanced coxarthrosis, than expected. Based on the results of this study, we considered that the Modified Chiari’s procedure is most effectively indicated for mature patients with the flat headed hip joints complicated by acetabular sclerosis. Therefore, we perform this procedure in combination with femoral valgus osteotomy. In contrast, satisfactory results cannot be expected from this combination therapy particularly in patients with the atrophic type roundheaded hip joints exhibiting poor acetabular sclerosis. It is considered that the Modified Chiari’s procedure will be a useful treatment modality substituting for total hip arthroplasty even in mature patients, if applicable cases are carefully selected. Subsequently, we radiographically evaluated the prognosis of the acetabulum based on its preoperative status. Levels of acetabular sclerosis were classified into the following 3 grades : : atrophic, nornopholic and hypertrophic type.After surgery, the joint space was dilated or maintained in all patients with the hypertrophic type hip joints. However, most patients with the atrophic type hip joints showed the poor prognoses because the stage of coxarthrosis was further advanced in 18% of them. Concerning the capital morphology before surgery, when the prognoses were evaluated based on the preoperative capital morphology, 96% of the proliferative headed hip joints were successfully treated, while only 83% of the round headed hip joints were successfully treated. Even when the stage of coxarthrosis advanced during the prolonged period of follow-up and total hip arthroplasty is performed, it is the merit of this procedure that a larger size cup be applied without bone grafting.Because the matrix is formed satisfactorily in the newly generated acetabulum where osteotomy was performed. The present study evaluated the results of the Modified Chiari’s procedure performed mature patients with advanced coxarthrosis caused by acetabular dysplasia . Clinically, the JOA score was markedly improved in 84% patients. Radiographically, the coverage of the femoral head was more delated in 52%, compared to the joint space before surgery. However, the joint space narrowed in 18 patients, and total hip arthroplasty was performed in 6.3%. Modified Chiari method was considered to be a useful treatment modality that can sufficiently substitute for total hip arthroplasty in selected cases

The aim of the study was to determine the mid-term clinical result of the patient operated by Chiari pelvic osteotomy. A mid-term evaluation of the Chiari pelvic osteotomy performed on 65 hips in 58 patients is presented. Indications were: 1) congenital hip dysplasia in cases where conservative or other surgical treatment had failed, 2) deformed, laterally uncovered femoral head due to Legg-Calvé-Perthes disease, 3) age between 10–40 years, 4) no signs of advanced osteoarthritis. Patients were classified according to pain, limp, Trendelenburg sign, range of motion, abductor muscle strength, and radiographic appearance (Wiberg and Idelberger angles). A mean follow-up of five years revealed relief of pain and an increase of hip motion in many cases. However, limping and a positive Trendelenburg sign frequently persisted. The radiographic appearance showed that the Wiberg angle had increased from the preoperative average of 6 degrees to 30 degrees postoperatively. The Idelberger angle decreased from the preoperative average of 72 degrees to an average of 60 degrees postoperatively. The Chiari osteotomy is a technically exacting procedure which provides adequate femoral head coverage. This coverage facilitates pain relief and increased function. However, the results were less consistent in the cases of Perthes disease. Considering the indications and contra-indications, the Chiari pelvic osteotomy has good clinical results in the reduction of painful standing and walking of young adult patients with DDH

We compared the clinical and radiological effects of the Salter and the Chiari pelvic osteotomy on congruent dysplastic adolescent hips with mild symptoms and free of degenerative changes. The Salter innominate osteotomy has a significant role in the surgery of paediatric hips with significant elasticity of triradiate cartilage, while the Chiari procedure is reserved for incongruent dysplasia with mild or moderate arthrosis in adolescents or young adults. Neither of these operative procedures is an ideal indication for congruent dysplastic adolescent hips free of arthrosis. Hypothetically, the residual remodelling potentials of immature congruent dysplastic adolescent hips can be sufficient to overcome the disadvantages of the Salter and the Chiari osteotomy and give good, long-lasting results. The effects of these quite different procedures in two homologous groups were compared. There were 30 hips treated with Chiari and 25 hips corrected by Salter osteotomy. All hips were congruently dysplastic according to the distance between the centres of the femoral head and the acetabulum (Klaue et al., classification). Groups were homologous considering mean age (14.5 years), follow-up period (8.5 years), presence of preoperative pain, Trendelenburg sign, and degenerative changes. Assessment for pain and Trendelenburg sign was made at follow-up. Radiological measurement was made of the central-edge angle of Wiberg (CE), acetabular angle of Sharp (AAS), and the femoral head coverage index of Heyman and Herndon (FHC). Progression of degenerative changes was analysed according to the criteria of Kellgren and Lawrence. At follow-up in the Chiari group, presence of pain was reduced from 54% to 6.6%, and from 35% to 12% in the Salter group. The presence of Trendelenburg sign was reduced 3% in the Chiari group and remained the same in the Salter group. At control, mean values of radiological parameters were normal in both groups (Salter: CE-27.8°, AIS-36.8°, ING-82.8%; Chiari: CE-36.8°; AIS-39.7°; ING-90.8%). Individual analysis showed 16% of dysplastic hips in the Salter group, and none in the Chiari group. Only one hip (4%) had grade 1 arthrosis after Salter osteotomy. There were five grade 1 hips (17%) in the Chiari group and one (3%) grade 2 arthrotic hip. At follow-up (mean 8.5 years) greater reduction of pain was found in the Chiari group than in the Salter group, but the presence of Trendelenburg sign remained almost unchanged in both groups. There was normalisation of the mean values of radiological parameters in both groups, but the Salter osteotomy was unable to correct dysplasia in 16% of the adolescent hips. Progression of degenerative changes was more rapid in the Chiari group

The purpose of the study was to analyse the clinical and radiological results of cementless HAP-coated Mallory- Head hip replacement in dysplastic hips. The collective included 20 males and 30 females (64 hips), with a mean age of 52.6 (range 20–68) years at operation. We also included two patients (4 hips) with spondyloepiphy-seal dysplasia (dwarfism). All patients were operated by one surgeon (EvL) during the period 1991–1997. A majority had “champaign flute” type femur. A minority had a normal or “stove pipe” type femur (Dörr). Most patients had acetabular dysplasia classified as A or B (Eftekar); some were classified as C and one as D (after Schanz osteotomy). Previous operations included: derotating varous osteotomy (11), acetabular shelf plasty (9), Salter or Chiari pelvic osteotomy (4) and tenotomy of the hip adductors (2). After a mean follow-up of 57 (range 32 to 97) months, a clinical and radiological analysis was performed by an independent investigator (TG). Postoperatively no or only mild pain was reported by 89% of all patients. The VAS for pain (0–10) was excellent: 1.70 (0–7). Limping was reported in 23% and 75% used no support when walking. The HHS increased from 42 to 90 points. Complications were marginal and there were no infections. One patient developed habitual dislocation and a revision of the cup was perfomed. We saw two periprosthetic fractures of the femur: once during surgery (treated conservatively) and once after a fall (treated by plating). We saw one case of temporary ischiadical nerve palsy after leg lenghtening of 5 cm. There were two cases in which we had used 32mm heads, and PE-wear necessitated revision of the cup after seven and eight years follow-up, respectively. Cortical hypertrophy indicating stress transfer was found in 28% and located mostly on the borders of Gruen-zones 2, 3 and 5, 6. This cortical hypertrophy (“ballooning”) started to appear after 0.5 to 1 year and did not disappear after a longer follow up. Endosteal spotwelds were infrequently seen (9%) and in 13% of all patients we saw some form of halo- or shelf-formation at the distal stem. The criteria of Enghs fixation scale are not signs of loosening in the Mallory-Head HAP-coated femoral prosthesis. No radiolucent or radiodense lines were seen around the acetabular cup. In all cases but one (Schanz osteotomy) the anatomical centre of rotation could be restored. We conclude that the cementless Mallory-Head HAPcoated femoral prosthesis has shown, up to present time, excellent clinical and radiological results in hip dysplasia

We have reviewed 103 of 126 Chiari osteotomies carried out in our department between 1956 and 1987. The cases were graded radiologically, using the Japanese Orthopaedic Association (JOA) system, into a pre/early osteoarthritis (OA) group and an advanced OA group. In the pre/early group there were 86 hips. The mean follow-up was for 17.1 years (4 to 37). Preoperatively, 51 hips had an average JOA clinical score of 78.6 ± 8.4 points and the final mean JOA clinical score was 89.4 ± 12.5 points. Advanced degenerative change developed in 33.7% and one hip required a total replacement arthroplasty (TRA). Chiari osteotomy alone, without accompanying intertrochanteric osteotomy, was performed on 62 hips. For these the median survival time was 26.0 ± 2.5 years, using as the endpoint progression to advanced OA. Differences in survivorship curves related significantly to the severity of the preoperative OA, the shape of the femoral head and the level of osteotomy. In the advanced OA group, we followed up 17 hips for a mean of 16.2 years (1 to 27). Before operation, the mean JOA clinical score in 13 hips was 63.2 ± 7.9 points and the final score 84.0 ± 12.0 points. TRA was eventually carried out on four hips.

Our findings suggest that the Chiari osteotomy remains radiologically effective for about 25 years. The procedure is best suited to subluxated hips with round or flat femoral heads and early or no degenerative change. Intra-articular osteotomy can lead to osteonecrosis, and should be avoided. In hips with advanced OA, the Chiari procedure creates an acetabulum which facilitates later TRA, and may delay the need for this procedure in younger patients.

We treated 31 consecutive patients of mean age 43 years (22 to 59) with severe osteoarthritis of the hip secondary to dysplasia by valgus-extension osteotomy. The clinical results were analysed for factors which may have affected the outcome. The procedure was carried out only on one side and was combined with a Chiari pelvic osteotomy in four patients. The angle of valgus was between 30 and 40° with 10 to 20° of extension. The mean follow-up was 15 years (12 to 18). Clinical evaluation using Charnley’s modification of the system of Merle d’Aubigné and Postel showed that the mean score for pain had improved from 2.3 before operation to 4.2 at 15 years, and function from 2.3 to 4.2. Range of movement had decreased from 4.2 to 3.5. Fifteen patients (48.4%) had a pain score of 5 or 6 and were evaluated as satisfactory. Kaplan-Meier survivorship analysis showed a survival rate of 51% at 15 years after operation. Two preoperative factors had a significant positive correlation with the radiological results, namely the thickness of the capital drop osteophyte and the length of the roof osteophyte. We suggest that this procedure is effective for advanced osteoarthritis in the dysplastic hip in young and active patients if these factors are satisfactory on the preoperative radiographs

We have investigated the changes in the interposed capsule after a Chiari pelvic osteotomy, in an experimental study on dysplastic hips in 20 adolescent rabbits. Radiographic, macroscopic and microscopic observations were made up to 12 months after operation. The new acetabular roof had incorporated the interposed capsule and remodelled completely by six months. By 12 months there was a new, stable hip with continuity between the capsule and the original acetabular cartilage. Histologically, the capsule underwent metaplastic change to fibrocartilaginous tissue after six months, with some hyaline-like cartilage near the joint surface. These changes in the interposed capsule play an important role in the formation of a new joint after a Chiari pelvic osteotomy