Elevated risk of early reoperation in total hip replacement during the stage of unit closure: A population-based registry study of total hip and knee replacements in ­Finland, 1998–2011

Background and purpose — The effects of launch or closure of an entire arthroplasty unit on the first or last patients treated in these units have not been studied. Using a 3-year follow-up, we investigated whether patients who were treated at the launch or closure stage of an arthroplasty unit of a hospital would have a higher risk of reoperation than patients treated in-between at the same units. Patients and methods — From the Finnish Arthroplasty Register, we identified all the units that had performed total joint arthroplasty and the units that were launched or closed in Finland between 1998 and 2011. The risks of reoperation within 3 years for the 41,748 total hip and knee replacements performed due to osteoarthritis in these units were modeled with Cox proportional-hazards regression, separately for hip and knee and for the launch and the closure stage. Results — The unadjusted and adjusted hazard ratios (HRs) for total hip and knee replacements performed in the initial stage of activity of the units that were launched were similar to the reoperation risks in patients who were operated in these units after the early stage of activity. The unadjusted and risk-adjusted HRs for early reoperation after total hip replacement (THR) were increased at the closure stage (adjusted HR = 1.8, 95% CI: 1.2–2.8). The reoperation risk at the closure stage after total knee replacement (TKR) was not increased. Interpretation — The results indicate that closure of units performing total hip replacements poses an increased risk of reoperation. Closures need to be managed carefully to prevent the quality from deteriorating when performing the final arthroplasties.