Results and prognostic factors of valgus osteotomy in middle-aged patients with advanced or terminal osteoarthritis of the hip

Abstract

Background: From 1979 to 2005, a total of 279 hips in 249 patients with advanced and/or terminal-stage osteoarthritis of the hip underwent valgus osteotomy. Among them, we reviewed 256 hips in 229 patients (91.8%) with a minimum follow-up of 1 year. We reviewed the clinical and radiological results and analyzed prognostic factors that may have affected the postoperative outcome.

Methods: Clinical evaluation was made according to the Japanese Orthopaedic Association Hip score (JOA score). Radiological evaluation was made according to the criteria of Itoman. The Kaplan-Meier method was used to calculate the probability of survival of valgus osteotomy from the time of the operation until the endpoint of a subsequent operation. To examine prognostic factors, clinical parameters and radiographic measurements were compared between patients in an improved group and an aggravated group. Additionally, clinical parameters and radiographic measurements were used to evaluate the JOA score at the latest follow-up.

Results: The mean JOA score was 52.6 before the operation; it was 80.6, showing the most marked improvement, 5 years after the operation, gradually decreased thereafter; and it was 65.0 after 20 years. Radiological results were good or fair in 78% even 10 years after the operation. The survival rates were 91%, 63%, and 52%, respectively, at 10, 15, and 20 years after valgus osteotomy. Concerning prognostic factors, the improved group tended to show preoperative good range of motion and unilateral involvement. Concerning the association between prognostic factors and the JOA score at the latest follow-up observation, the JOA score was significantly lower for an acetabular head index (AHI) <60% than for AHI >or=60%.

Conclusions: Valgus osteotomy is effective joint-preserving surgery for advanced or terminal-stage osteoarthritis of the hip in middle-aged patients, and it is acceptable for clinical and radiological evaluation. If the AHI is <60%, valgus osteotomy should be combined with Chiari's pelvic osteotomy.