Objective: Hospital volume is a known indicator for orthopaedic adverse events in patients undergoing total hip replacement. The aim of the current study was to evaluate the effect of hospital volume on the length of stay, re-admissions and complications of THR on a population-based level in Finland.

Methods: Using the information from the Hospital Discharge Registry and that of four other National databases, 28,218 THRs performed for primary osteoarthritis were identified for the period covering 1998 to 2005. Hospitals were classified into four groups according to the number of primary and revision hip and knee replacements performed on an annual basis over the whole study period: 1–100 (Group 1), 101–300 (Group 2), 301–600 (Group 3) and 601 or over (Group 4). Logistic regression analysis and generalized linear models were used to study the effect of hospital volume on the length of stay, unscheduled re-admissions, re-operations, dislocations and infections.

Results: The lengths of both the surgical treatment period and the uninterrupted institutional care were shorter for the very high volume hospitals (Group 4) than for the low volume hospitals (Group 1) (p< 0.0001). The odds ratio for dislocations (0.71, 95% CI 0.56–0.91) was significantly lower in the high volume hospitals (Group 3), than in the low volume hospitals (Group 1, the reference group).

Conclusion: Specialization of hip replacements by high volume hospitals should reduce costs by significantly shortening length of stay, and may reduce the dislocation rate.