The results of Chiari pelvic osteotomy in adolescents with a brief literature review

Purpose Chiari medial displacement osteotomy is a procedure that uses the cancellous bone of the ilium to contain the femoral head and bear weight. It is the most contraversial osteotomy of the hip joint. This study was therefore conducted to determine the results of this osteotomy with mid-term follow-up in children. Methods From 1995 to 2004, 20 Chiari pelvic osteotomies (in 18 patients) were performed. There were 15 male and 3 female patients. The average age at operation was 12.6 years and the mean follow-up was 54 months. The operative technique was as described by Chiari. An iliofemoral approach was used without utilizing a traction table. If there was anterior or anterolateral uncoverage of the femoral head, bone graft augmentation was performed. Results The angle of the osteotomy averaged 12°, with the distance from the acetabulum averaging 3.2 mm. The average displacement was 42%. Of the 20 Chiari osteotomies, 11 were categorized as excellent, 8 as good and one as fair in terms of clinical and radiological results. Student’s t test statistics showed improvements in all radiologic parameters of the hip joint (Sharp angle, center-edge angle and coverage of the femoral head). Graft resorption was observed in 25% of the patients. Conclusion There are very rare indications of Chiari osteotomy in patients younger than 10 years. Because of the high rate of graft resorption, Chiari osteotomy should be the last treatment option when there is anterior or anterolateral uncoverage of the hip joint.     

Chiari pelvic osteotomy in the treatment of adolescent hip disorders: possibilities, limitations and complications

Ninety-nine hips treated by the Chiari pelvic osteotomy were included in this study designed as a retrospective review. The group consisted of 36 male and 50 female patients, with mean age of 15.6 years. Each was diagnosed with developmental dysplasia of the hip (DDH) or avascular necrosis of the femoral head—Legg-Calve-Perthes disease (LCP)—and postreduction avascular necrosis (PAN). Five hip parameters (the acetabular angle of Sharp, the center-edge (CE) angle of Wiberg, the percentage of femoral head uncoverage, the acetabular depth ratio, and the Shenton-Menard arch continuity) were evaluated. Functional outcome was assessed according to Harris hip score (HHS) and McKay criteria for clinical evaluation. The postoperative results showed improvement in all the radiographic parameters. The angle of Sharp showed a decrease of 8.62o (p < 0.01). The CE angle of Wiberg showed an increase of 28.76o (p < 0.01), and the uncoverage of the femoral head showed a decrease of 51.51% (p < 0.01). The improvement of HHS was 11.93 (p < 0.05). The patients’ satisfaction was indicated by grade 4.1 ± 0.94 and the doctor’s satisfaction by grade 3.7 ± 1.16. The Chiari pelvic osteotomy, in spite of the development of biologically better procedures, has retained its position in the treatment of adolescent hip disorders.     

Total hip arthroplasty of dysplastic hip after previous Chiari pelvic osteotomy

Introduction: Many reports have suggested that Chiari pelvic osteotomy would improve the results of acetabular component placement and fixation in subsequent total hip arthroplasty. However, little is known concerning the biomechanical, radiological, and clinical effects of Chiari pelvic osteotomy on subsequent total hip arthroplasty. Materials and methods: Ten total hip arthroplasties for developmental dysplasia of the hip after previous Chiari pelvic osteotomy (Chiari group) were compared with 20 total hip arthroplasties for developmental dysplasia of the hip without previous surgery (control group). Preoperative patient demographic data and operative technique were well matched between the groups. The mean duration of follow-up was 3.0 years. Biomechanical, radiological, and clinical evaluations were performed. Results: No acetabular or femoral components exhibited loosening. All patients had good or excellent clinical score according to the Merle d’Aubigne-Postel rating system at the most recent follow-up. Abductor force and joint force were smaller in the Chiari group, although long operative time, more blood loss, and verticalization of joint force were noted in this group. Conclusion: This limited study suggested that Chiari pelvic osteotomy changed the biomechanical features of the hip joint, and that this alteration might have compromised subsequent total hip arthroplasty.     

Pelvic osteotomy techniques and comparative effects on biomechanics of the hip: a kinematic study

Dysplasia of the hip is characterized by malpositioning of the proximal femur in a shallow acetabulum, providing deficient femoral head coverage. This abnormal relationship leads to altered biomechanics of the hip joint, as predicted by measurement of kinematic parameters such as increased load over reduced acetabular weight-bearing area, leading to increased joint contact stresses, which subsequently results in secondary osteoarthrosis, pain, and disability. To prevent these sequelae, particularly in children and younger adults, various osteotomies have been performed with varying degrees of success. The goal of this study was to devise a simple and reproducible laboratory method to perform a kinematic analysis of the individual and comparative effects of 5 commonly performed pelvic osteotomy techniques: Chiari pelvic osteotomy, Salter innominate bone wedge osteotomy, Steel triple pelvic osteotomy, T?nnis triple pelvic osteotomy, and Ganz periacetabular pelvic osteotomy. The aim was to determine which of the osteotomy techniques caused greater correction in most of the kinematic parameters used to estimate changes in the biomechanics of the hip joint. Our hypothesis was that pelvic osteotomies such as Chiari and Salter produced favorable changes and were relatively easily reproducible, but that more biomechanical correction in all planes would be achieved by the relatively more complex triple innominate bone and Ganz osteotomy.     

Long-term survivorship of hip shelf arthroplasty and Chiari osteotomy in adults

The current authors retrospectively assessed 56 hip shelf arthroplasties (48 patients) with a mean followup of 17 years (range, 15-30 years) and 89 Chiari osteotomies (82 patients) with a mean followup of 13 years (range, 6-25 years) done in adults with painful hip dysplasia. Preoperative joint space narrowing was observed in 32 of 56 shelf arthroplasties and in 67 of 89 Chiari osteotomies. Survival rates, using hip replacement as the end point, were 37% (20% to 54%) at 20 years for shelf arthroplasty and 68% (54% to 81%) at 18 years for Chiari osteotomy. The severity of preoperative arthrosis was the main factor that impaired the survivorship of shelf arthroplasty and Chiari osteotomy. With arthritic changes without joint space narrowing, the 18-year survival rates were 83% (69% to 97%) for shelf arthroplasty and 94% (89% to 99%) for Chiari osteotomy. Shelf arthroplasty is best indicated for moderate dysplasia (center edge angle >0 degrees) without severe arthrosis. Chiari osteotomy is best suited for severe dysplasia (center edge angle <0 degrees) especially without or with slight arthrosis. Chiari osteotomy also can be a salvage procedure when marked joint space narrowing is present but only if it is related to severe dysplasia (center edge angle <0 degrees).     

Dynamics of hip joint remodeling after Chiari osteotomy: 10 patients with neuromuscular disease followed for 8 years

We analyzed the development of 10 hips in 10 consecutive patients with neuromuscular disease (9 with spasticity, 1 with Charcot-Marie-Tooth disease) who had undergone Chiari osteotomy for painful hip subluxation or dislocation. The patients were 11 (5-19) years old at surgery and follow-up time was 8 (6-11) years.

The Chiari osteotomy particularly improved and maintained femoral head coverage. These parameters did not show the postoperative deterioration noted in some other studies. The osteotomy did not improve femoral head lateral displacement. Throughout the postoperative period, the configuration of the proximal femur and the height of the joint cartilage were unchanged and undisturbed, indicating that osteotomy did not place excessive or uneven pressure on the femoral head.

The ambulatory status of the patients was dependent on the severity of the underlying disease, and was not improved by osteotomy. However, pain associated with subluxation or dislocation was reduced in 9 of the patients.     

Long-term results of Chiari pelvic osteotomy in patients with developmental dysplasia of the hip: indications for Chiari pelvic osteotomy according to disease stage and femoral head shape

Background We evaluated the long-term results of Chiari pelvic osteotomy for developmental dysplasia of the hip (DDH) after follow-up of 10 years or more. The indications for Chiari osteotomy were assessed based on the results. Methods We evaluated 74 hips in 69 patients treated for DDH with Chiari osteotomy. The average postoperative follow-up period was 13 years. The mean age at the time of surgery was 32 years (range 6–64 years). The disease was classified into two stages based on joint space measurements on radiographs: an early stage (36 hips) in which the mean age at surgery was 21 years (range 6–48 years) and an advanced stage (38 hips) in which the mean age at surgery was 41 years (range 18–64 years). Femoral head shape was classified into two types based on measurements of the sphericity of the femoral head: spherical (33 hips) or flat (41 hips). Clinical manifestations were evaluated according to Japanese Orthopaedic Association (JOA) hip scores. The joint space was measured on radiographs as an index of the progression of osteoarthritis. We attempted to identify factors that affected the long-term results of Chiari osteotomy, especially in regard to disease stage and femoral head shape. Results The mean total JOA score was 72 preoperatively and 87 at final follow-up. It had improved in 66 hips and was worse in 7 hips. All of the worse cases were at the advanced stage at the time of surgery, and in 6 of the worse cases the femoral head was spherical. Hips with advanced DDH and a spherical femoral head had poor outcomes and exhibited joint space narrowing postoperatively. Conclusions Early DDH is considered a good indication for Chiari pelvic osteotomy because of the good results at 10 years or more. Even with advanced DDH, a flat femoral head predicts a good surgical outcome, but patients with a spherical femoral head may experience early progression to osteoarthritis.     

Chiari pelvic osteotomy in the treatment of hip dysplasia in adults]

INTRODUCTION: [corrected] The aim of the study is early results evaluation of Chiari pelvic osteotomy. MATERIALS AND METHODS: In the years 1997-2003 36 patients (26 women and 10 men) in the age from 16 to 50 years old were operated on because of hip joint dysplasia. The indications for operative treatment were: pain, age less than 50 years, insufficient femoral head coverage without evidence of arthritic changes on X-ray. RESULTS: There were no intraoperative and postoperative complications. Harris Hip Score improved from 85 points before operation (from 82 to 90 pts.) to 95 points (from 92 to 100 pts.) after operative treatment. There was pain relief in most of the patients after osteotomy. Osteotomy healing was seen on X-ray examination usually after 6-12 weeks in 33 patients. Delayed osteotomy union till 6th postoperative month without influence on clinical hip improvement was seen in 3 patients. The increase in Wiberg CE angle from average 17.2 degrees (from 3 to 33 degrees) before operation to 44.9 degrees (from 19 to 78 degrees) after operation was statistically significant p< 0.00045. There was no loss in osteotomy correction. CONCLUSION: Supraacetabular osteotomy decreases pain, and increases hip function. Improvement in hip biomechanics and increase in femoral head coverage may lead to decrease in development of hip joint arthritic changes and time preserve before total hip arthroplasty.     

Chiari pelvic osteotomy for advanced osteoarthritis in patients with hip dysplasia

BACKGROUND: It is not clear whether a Chiari pelvic osteotomy performed for the treatment of advanced osteoarthritis can delay the need for total hip arthroplasty. We present the mid-term results of the Chiari pelvic osteotomy performed for the treatment of T?nnis grade-3 osteoarthritis (large cysts, severe narrowing of the joint space, or severe deformity or necrosis of the head with extensive osteophyte formation), with a particular focus on whether this procedure can delay the need for total hip arthroplasty. METHODS: We followed thirty-two hips in thirty-one patients with T?nnis grade-3 osteoarthritis who had refused total hip arthroplasty and had been treated with a Chiari pelvic osteotomy. The mean age at the time of surgery was 35.2 years. The mean duration of follow-up was 11.2 years, at which time clinical evaluation with the Harris hip score and radiographic evaluation were performed. RESULTS: The average Harris hip score improved from 52 points preoperatively to 77 points at the time of follow-up; the average pain score improved from 20 to 31 points. Three hips with a hip score of <70 points required total hip arthroplasty. With a hip score of <70 points as the end point, the cumulative rate of survival at ten years was 72%. The clinical outcome was significantly influenced by the preoperative center-edge angle (p = 0.004), the preoperative acetabular head index (p = 0.039), achievement of the appropriate osteotomy level (p = 0.011), and superior migration (p = 0.009) and lateral migration (p = 0.026) of the femoral head. CONCLUSIONS: Although the clinical results were inferior to those of total hip arthroplasty, Chiari pelvic osteotomy may be an option for young patients with advanced osteoarthritis who prefer a joint-conserving procedure to total hip arthroplasty and accept a clinical outcome that is predicted to be less optimal than that of total hip arthroplasty. Moderate dysplasia and moderate subluxation without complete obliteration of the joint space and a preoperative center-edge angle of at least -10 degrees are desirable selection criteria.     

Three-dimensional computed tomography analysis and anteversion study after periacetabular osteotomy of pelvis in children

Purpose Three-dimensional computed tomography (CT) is the method of choice in understanding the morphological changes after periacetabular osteotomy in children. We studied different parameters and compared aspects of operated hip (OH) with non-operated hip (NOH) to define the maneuver that promotes normalization of the hip during repositioning of the acetabulum. Methods A total of 22 patients with 25 OHs underwent CT control scans an average of 4 years after surgery. The patients, with a mean age of 6.8 years, had either Legg-Calvé-Perthes disease (12 cases) or dysplasia (10 cases).The measurements included the anterior and posterior coverage angles of the hip and version of the acetabulum on axial CT views. The 3D reconstructed images measured the inclination of the antero– and postero–lateral lips, the external rotation and the anterior inclination of the acetabulum. Results The mean anterior coverage angle was 27° for OHs, 31° for NOHs, and 12° versus 10.3° for the posterior coverage angle. Acetabular anteversion was 2° for OHs (6.3° in the dysplastic OHs) and 6° for NOHs. The mean angle of inclination of the antero–lateral lip was 37° for OHs, 47° for NOHs, and the postero–lateral lip inclination was 56° for OHs and 67° for NOHs. Inferior 3D views showed a mean internal acetabular rotation of 1.5° (4.8° in the dysplastic OH), 3° for NOH. The anterior acetabular inclination angle measured with lateral 3D views was 6° for OHs, 11° for NOHs. Conclusion Our analysis demonstrated a mean anteversion of the acetabulum despite normalization of the anterior coverage of the hip, particularly in the dysplastic group, in which the osteotomized fragments had anteversion superior to NOH. The unexpected external rotation used to improve anterior coverage of a coax magna in Legg-Calvé-Perthes disease was responsible for the retroversion and the decrease of the posterior coverage.     

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.     

Chiari osteotomy in Legg-Calve-Perthes disease

A retrospective study of 22 Chiari osteotomies in 21 children with severe Legg-Calve-Perthes disease is presented. All cases were studied at skeletal maturity. The average age at surgery was 8.5 years with an average follow-up of 6.1 years. Four hips were classified as Catterall group III and the remaining hips as group IV. Arthrography was used preoperatively to measure the femoral head sphericity, the femoral head coverage and the eccentric index. The same parameters were studied on radiographs at skeletal maturity. Chiari osteotomy provided an improvement in the femoral head coverage and hip congruency. Radiographs showed progressive spherical remodelling of the femoral head and improvement of the concentricity. One hip required premature total hip replacement.     

Chiari osteotomy and shelf augmentation in the treatment of hip dysplasia

The clinical and radiographic results of Chiari osteotomy and shelf augmentation for acetabular dysplasia in 30 hips were reported. The average age at operation was 17 years for Chiari osteotomy and 13.8 years for shelf augmentation. The mean follow-up was 7.1 years for Chiari osteotomy and 4.1 years for shelf augmentation. Of the 14 Chiari osteotomies, 12 had good results by Tonnis clinical grading and 2 had poor results. There were significant improvements in the radiographic parameters measured (p < 0.01). They included center-edge angle of Wiberg, the acetabular angle of Sharp, the percentage of femoral head coverage, and the "c/b" ratio. For the 16 shelf augmentations, there were 8 good, 2 fair, and 6 poor results. The radiographic parameters measured were also all significantly improved (p < 0.01). The final Severin grading of the hips were improved by both Chiari osteotomy and shelf augmentation.     

Biomechanical analysis of the Chiari pelvic osteotomy. Preserving hip abductor strength

Although the Chiari osteotomy is usually effective in reducing pain, many patients are left with a long-term limp. The postoperative limp can at times be caused by hip abductors that have strength insufficient to counteract the torque from body weight during single-leg stance. To study how the surgical technique affects the hip abductor muscles, a biomechanical model was developed that computes the postsurgery pelvic geometry and the resulting hip abductor torque given three surgical parameters: angulation of the osteotomy, distance of medical displacement, and angle of internal rotation. The computer simulations of the Chiari osteotomy showed that some sets of surgical parameters conserve abductor torque while others greatly reduce it. Simulated surgeries with high angulation and large medial displacement reduce gluteus medius abductor torque by up to 65%. Therefore, this combination of surgical parameters may account for some instances of the postoperative limp. In the model, high angulation reduces the length of the gluteus medius and is the primary cause of reduced abductor strength. Simulated horizontal osteotomies (0 degrees to 10 degrees) were found to best conserve both muscle length and abductor torque.     

Calcaneal lengthening osteotomy in spastic planovalgus feet

Purpose of StudyPlanovalgus deformity in cerebral palsy is disabling for the child in terms of increased energy expenditure during the gait cycle. The lever arm function of the foot is lost due to midfoot break and the achilles tendon is at a disadvantage being unable to lift the body weight during push-off. We evaluated the results of calcaneal lengthening osteotomy in such patients with clinical, radiological and gait parameters.Methods17 spastic feet in a sample of 10 children were included in our study. The children were classified according to the GMFCS classification system and clinical parameters such as heel valgus and heel rise tests, radiological angles such as Talo-calcaneal angle and Talo-navicular coverage angle on AP view and Calcaneal pitch angle, calcaneus-5th metatarsal angle and talus-1st metatarsal angle on lateral view were measured. Video gait analysis was performed to observe knee progression angle in mid stance and peak knee flexion angle in mid and terminal stance.ResultsImprovement was noted clinically in the heel valgus angle (preop-12.06°, postop-5.12°) and radiological parameters showed an improved coverage of the talus by navicular with simultaneous lifting of the medial longitudinal arch. Gait analysis showed decreased knee flexion trend in mid and terminal stance phase with better restoration of the knee axis.ConclusionCalcaneal lengthening osteotomy with peroneus brevis lengthening corrects almost all aspects of planovalgus deformity with an improved gait pattern without disturbing joint range of motion. It is a safe procedure for GMFCS grade 1 and 2 patients without much complications.     

Biomechanics of the Chiari pelvic osteotomy

We have reviewed our findings on 476 hip joints that underwent a Chiari pelvic osteotomy (Chiari) between June 1983 and March 1990, employing computer simulation using non-linear analysis based on the rigid-body spring model (RBSM) proposed by Kawai. We further made estimates of the changes in the hip abduction force resulting from the Chiari. The abduction force was measured by a Cybex II machine, before and after Chiari, and they were compared with those from simulation modeling (using the abduction muscle model: ABMM) for the power change expected by Chiari. According to the results in the RBSM, the resultant force, the abduction force, deviation of the pelvis, and the joint stress improved outcome after Chiari. Chiari had a positive effect on the peak torque of the hip abduction, though the abduction force was not fully restored clinically. The simulation by ABMM, showed similar results with the abduction force decreasing with increasing degree of hip abduction. From these results, we have developed and established a new technique for the reattachment of the greater trochanter in Chiari.     

Chiari medial displacement osteotomy

The results of 36 Chiari medial displacement osteotomies of the pelvis were studied to determine the efficacy of the operation in the treatment of subluxated and/or painful dysplastic hips. Fifteen of 16 osteotomies performed for congenital hip dysplasia provided satisfactory coverage, pain relief, and increased function. The results were less consistent in patients with myelodysplasia, spasticity, and Perthes disease. The Chiari osteotomy is a technically exacting procedure capable of providing adequate femoral head coverage. This coverage facilitates pain relief and increased function. This procedure is most suited for those individuals with a painful hip subluxation in whom a concentric reduction is not possible.     

Primary stability of various implants in tibial opening wedge osteotomy: a biomechanical study

 High tibial osteotomy (HTO) is an established method for treating varus gonarthrosis. The opening wedge HTO has some advantages over the lateral closed wedge technique. In this biomechanical study various systems of internal fixation of medial HTO were compared using an animal cadaver model (lower leg specimens from 1-year-old female domestic pigs). The first osteotomy (10°) was carried out and stabilized with a C-plate, an Arthrex spacer plate, or an AO tibial plate with or without bone graft. The resistance to axial stress was tested in a mechanical testing machine. Under lower axial stress (25, 50, 75, 100 N) the axial displacement between the various specimens did not show any significant differences. Under maximal axial force, the specimen fixed with the C-plate (F _max 2042 N) showed significantly better stability than the Arthrex plate (F _max 1687 N); P < 0.05. The AO plate (F _max 1612 N without bone graft and F _max 1583 N with bone graft) showed the lowest axial exposure to stress. Moreover, the influence of the osteotomy angle (7.5°, 10°, 12.5°, 15°) on axial stress resistance (F _max 2548, 2090, 1975, and 1740, respectively) was evaluated, and a direct correlation was found (R = 0.794, P < 0.05). Received: April 12, 2002 / Accepted: July 8, 2002 Offprint requests to: G. Spahn     

Chiari pelvic osteotomy in Perthes disease

A retrospective study of 17 Chiari osteotomies performed on patients with Perthes disease who were followed until the end of growth is presented. The average age at operation was 8 years 9 months. Catterall grading was mainly group IV. Chiari osteotomy provided satisfactory femoral head coverage with a decreased acetabular index and a 19.6 degrees improvement of the Wiberg angle. Good femoral coverage was related to age at operation and the site of the osteotomy on the upper rim of the acetabulum. The postoperative result was less successful on younger patients or when the osteotomy was performed higher. At follow-up, the results of femoral head sphericity studied by Mose measurements were favorable under Catterall grading.     

Mid-term results of Scarf osteotomy in hallux valgus

We performed a retrospective study on 178 Scarf osteotomies with a mean follow-up of 44.9 months (range 15–83 months). Clinical rating was based on the forefoot score of the American Orthopaedic Foot and Ankle Society (AOFAS). Weight bearing X-rays were used to perform angular measurements and assess the first metatarsophalangeal joint (MTP 1). At follow-up the mean AOFAS score had improved significantly (p < 0.001), but only 55% of the feet showed a perfect realignment of the first ray. Patients with a hallux valgus angle exceeding 30° and pre-existing degenerative changes at the MTP 1 joint displayed inferior clinical results (p < 0.05). Nearly 20% of the patients suffered from pain at the MTP 1 joint. This was clearly attributed to an onset or worsening of distinct radiographic signs of arthritis (p < 0.05) resulting in painfully decreased joint motion. Comparing radiographic appearance three months postoperatively and at follow-up, we found that radiographic criteria (hallux valgus, first intermetatarsal angle, hallux valgus interphalangeus, MTP 1 joint congruency, arthritic lesions at MTP 1) worsened with time.