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.