Background: The purpose of this study was to clarify the volume-outcome relations for total hip arthroplasty, with a particular focus on outcome variables such as operating time, blood loss, and postoperative complications.
Methods: Using an Internet-based questionnaire survey, we identified 2965 total hip arthroplasties performed for osteoarthritis, idiopathic osteonecrosis of the femoral head, rheumatoid arthritis, or hip fractures in 289 hospitals in Japan during the period from November 1, 2006, to March 31, 2007. We examined the hospital and surgeon volumes, patient characteristics (age, sex, body mass index, diagnosis, drug history, co-morbid conditions), details of the surgical procedures, and outcome variables (operating time, blood loss, postoperative complications). Multivariate regression analyses were used to examine the relations between the outcome variables and hospital/surgeon volumes, adjusting for patient characteristics and surgical details.
Results: The average operating time was 114 +/- 62 min. The average blood loss was 429 +/- 347 ml. The postoperative complication rate was 6.1%. Surgeon volume (> or = 500 cases) was inversely associated with operating time (odds ratio 0.20; P < 0.01), blood loss (odds ratio 0.54; P = 0.02), and postoperative complications (odds ratio 0.53; P = 0.01). Hospital volume was not significantly associated with any of the outcome variables examined.
Conclusions: The present study indicates that surgeon volume is a significant predictor of better outcomes after total hip arthroplasty.