Primary total knee arthroplasty in patients receiving workers' compensation benefits.

OBJECTIVE: To determine the influence of Ontario Workplace Safety and Insurance Board (WSIB) benefits on short-term clinical outcomes of primary unilateral total knee arthroplasty (TKA). METHODS: In a retrospective matched-cohort study at a single tertiary-care arthroplasty centre in Ontario, we compared a study cohort of 38 successive primary TKA patients receiving WSIB benefits from 1998 to 2002 to 38 controls, a matched cohort of non-WSIB patients, comparing Oxford Knee Score and Knee Society Score (both clinical and functional components) as well as flexion and pain variables, preoperatively and at postoperative intervals of 6 weeks, 6 months and 1 year. At least 1 year after their surgery, all patients were asked to complete a non-validated patient satisfaction survey. The number of clinic visits related to the operation was also compared, by means of Ontario Hospital Insurance Plan billing codes for each individual. RESULTS: Preoperative measurements showed the 2 groups to be similar. At follow-up, WSIB patients had significantly higher pain scores, poorer self-perceived functional outcomes and a lower range of knee flexion than the control group. WSIB patients also required more postoperative clinic visits and were more reluctant to answer questions about functional outcome. CONCLUSIONS: Short-term outcomes of primary TKA in patients receiving WSIB benefits are inferior to those of non-WSIB patients. WSIB patients are seen more frequently for postoperative follow-up, which we would attribute to the persistence of subjective complaints after TKA.