Complications After Total Knee Arthroplasty in Patients With Pigmented Villonodular Synovitis.

BACKGROUND: Pigmented villonodular synovitis (PVNS) is a locally destructive histiocytic proliferation most commonly occurring in the knee. Extensive local joint destruction can indicate the need for a total knee arthroplasty (TKA). The objective of this study is to evaluate PVNS of the knee as a risk factor for complication after TKA.

METHODS: Patients who underwent TKA with a diagnosis of PVNS of the knee from 2007 to 2016 were identified in a national private payer insurance database. Complication rates for emergency room visits, readmission, revision, stiffness, infection, and death were calculated and compared to a control population of patients who received TKA for osteoarthritis (OA).

RESULTS: Four hundred fifty-three patients were diagnosed with PVNS of the knee and underwent TKA during the time period and compared with a matched control cohort of 1812 patients who underwent TKA for OA. The rate of revision TKA at 2 years, emergency room visits, readmission, and death did not differ between the PVNS group and the control cohort. The PVNS group had stiffness at 1 year compared to the OA group (6.84% vs 4.69%, odds ratio 1.48, P = .023). The infection rate at 2 years was 3.31% in the PVNS group and 1.55% in the OA group (odds ratio 1.73, P = .011).

CONCLUSION: The complication rates for TKA in patients with a diagnosis of PVNS of the knee have not been previously demonstrated. These patients have a higher rate of stiffness and infection when compared to a control cohort, so they may have a more complicated postoperative course.