Are complication rates for elective primary total hip arthroplasty in Ontario related to surgeon and hospital volumes? A preliminary investigation.

OBJECTIVE: To test the hypothesis that complication rates for elective total hip replacement operations are related to surgeon and hospital volumes.
DESIGN: Retrospective population cohort study. STUDY COHORT: Patients who had undergone elective total hip replacement in Ontario during 1992 as captured in the Canadian Institute for Health Information database. MAIN OUTCOME MEASURES: In-hospital complications, 1- and 3-year revision rates, 1- and 3-year infection rates, length of hospital stay, and 3-month and 1-year death rates.
RESULTS: Surgeons with patient volumes above the 80th percentile (more than 27 hip replacements annually) discharged patients approximately 2.4 days earlier (p < 0.05) than surgeons with volumes below the 40th percentile (less than 9 hip replacements annually) even after adjusting for discharge disposition, hospital volume, patient age, sex, comorbidity and diagnosis. Complication rates requiring hospital readmission and death rates did not differ by surgeon or hospital volume (p > 0.05).
CONCLUSIONS: There is no evidence to support regionalization of elective hip replacement surgery in Ontario based on adverse clinical outcomes. Surgeons who perform a large number of total hip replacements are discharging patients earlier than less experienced surgeons, without any-demonstrable increase in complications leading to hospital readmission. The explanation for this observation remains unknown and will require further study.