Ultra-long-term results of the Chiari pelvic osteotomy in hip dysplasia patients: a minimum of thirty-five years follow-up.

PURPOSE: The Chiari pelvic osteotomy was the first surgical procedure to address hip dysplasia by changing the position of the acetabulum by medialization, thus creating a bony roof and improving biomechanical conditions. The aim of this retrospective cohort study was to report on the very long-term results of this technique. METHODS: Out of a consecutive series of 1536 hips, 504 in 405 patients were available for follow-up. The patients were assessed by physical and radiological examination. A Kaplan-Meier survival analysis with total hip arthroplasty as an endpoint was performed and stratified for age groups, pre-operative diagnosis, sex and osteoarthritis stage. RESULTS: The average follow-up was 36 ± 8.1 years (range, 35.2 to 54). The average pain level on the Visual Analogue Scale was 2.9 ± 2.6 (range 0 to 8.7). The average Harris Hip Score was 80.2 ± 17.4 (range 17.4 to 100). Correction of dysplasia was effective and remained stable over time. Osteoarthritis significantly increased over time with 53% Tönnis grade 3 at follow-up. The cumulative survivorship was 79.8% (95% confidence interval (CI), 76.1-83.2%) at 20 years, 57.1% (95% CI, 52.8-61.8%) at 30 years and 35% (95% CI, 30.3-40.3%) at 40 years. Young age, male sex and low osteoarthritis grade were positive prognostic factors. CONCLUSIONS: Although the Chiari pelvic osteotomy is considered a salvage procedure nowadays, it achieved excellent long-term results even in indications, which would be treated differently today. Young patients without osteoarthritis had the best outcome.

Long-Term Results after Chiari Pelvic Osteotomy in the Skeletally Immature and the Role of the Anti-Chiari Effect.

Several authors observed a loss of correction after performing Chiari pelvic osteotomy (CPO) in young patients. Hence, the aim of this study was to answer two questions: (1) Does the Chiari pelvic osteotomy affect the development of the acetabulum in skeletally immature patients in the long term? (2) Is there any evidence of the previously described "Anti-Chiari" effect after a mean follow-up of 36 years? Data from 21 patients (27 hips) undergoing CPO before the age of 16 years were clinically assessed, and the evolution of radiological parameters over time was analyzed. The mean age at CPO was 11.2 years (±3; 4.4-15.7). The 20- and 30-year survival rates of the CPO were 100% and 92.6%, respectively. Mean postoperative medialization was 54% (±18; 23-99). The average osteotomy angle was 11° (±7; 2-28). No significant changes were found for the center-edge angle (CEA) and acetabular index (AI) over time; the angle of Idelberger and Frank (ACM) almost reached normal values at follow-up (FU); for the acetabular-head index (AHI), a slight shift toward the initial situation could be detected. The morphology of the acetabulum remained unchanged over time. The "Anti-Chiari effect" seems to be primarily caused by insufficient coverage of the femoral head rather than damage to the apophysis due to surgery.

Total Hip Arthroplasty after Previous Chiari Pelvic Osteotomy-A Retrospective Study of 301 Dysplastic Hips.

BACKGROUND: Controversy exists whether previous pelvic osteotomies have negative effects on total hip arthroplasty (THA). This study evaluates the implant survival and patient-reported outcomes of THA after previous Chiari pelvic osteotomy (CPO). METHODS: Data on 301 THAs after CPO were collected through clinical and radiological follow-up examinations and telephone interviews. The Kaplan-Meier survivorship analysis depicts implant survival. RESULTS: Of this consecutive series of 1536 CPOs, follow-up was completed in 405 patients with 504 CPOs after a mean time of 36 years (±8; range, 22-54 years). At follow-up, 301 hips (60%) had already undergone THA. The overall survival of THA with revision as an end point after 10, 20, and 25 years was 93%, 76%, and 68%, respectively. The revision rate was 12%. The average period between THA and revision surgery was 9.6 years (±6.1; 4 months-25.4 years). The patient's age at revision was 57.9 years (±10; 33.2-78.5 years). Aseptic loosening was the most common of the known reasons for revision surgery. CONCLUSION: This retrospective study supports the hypothesis that prior CPO does not compromise the prerequisites for successful THA at a later stage. Survival rates of the implanted prosthesis are comparable to primary implanted hips, as overall survival was 93% after 10 years.

Biological Regeneration of Articular Cartilage in an Early Stage of Compartmentalized Osteoarthritis: 12-Month Results.

BACKGROUND: Biological regeneration in an early stage of osteoarthritis (OA) is an important clinical challenge. An early-stage compartmentalized OA model was used to evaluate different biological regeneration techniques. HYPOTHESIS: Biological regeneration in an early stage of compartmentalized OA is possible. STUDY DESIGN: Controlled laboratory study. METHODS: A 7-mm cartilage defect was surgically created in 24 sheep. After 3 months, by which time early OA had set in, the sheep were randomized into 4 different treatment groups and operated for the second time. One group (CONTROL) served as a long-term follow-up group for the further development of OA. The other 3 groups (regeneration groups) each underwent a different regeneration procedure after abrasion of the subchondral bone (defect size: 20 × 10 mm with a depth of 2.5 mm): spongialization alone (SPONGIO), spongialization followed by implantation of an unseeded hyaluronan matrix (MATRIX), or spongialization followed by implantation of a hyaluronan matrix seeded with autologous chondrocytes (MACT). Then, 12 months after the second operative procedure, the animals were euthanized and the defects subjected to macroscopic and histological grading. Historical 4-month data were compared with the 12-month results. RESULTS: After 12 months of follow-up, advanced cartilage degeneration was observed in the CONTROL group. On the other hand, all regeneration groups improved significantly compared with the 4-month results using the Mankin score. Cartilage quality in the MACT group was significantly better than in the MATRIX group, as determined by the Mankin and the O'Driscoll scores. CONCLUSION: There are no existing clinical options for preventing early OA from progressing to a severe disease. This study provides important information on how a surgical intervention can forestall the development of OA. CLINICAL RELEVANCE: OA of the knee is very common. Total joint replacement is not an acceptable option for active patients. Biological regeneration in OA is successful for focal cartilage defects; however, a long-term follow-up for biological regeneration in OA is missing. It is essential to have long-term results for a regenerative procedure involving cartilage, which is a tissue with a very slow turnover.