Systemic lupus erythematosus is not a risk factor for poor outcomes after total hip and total knee arthroplasty
OBJECTIVES: Historically, arthroplasty in systemic lupus erythematosus (SLE) patients has been less successful than for patients with osteoarthritis (OA). It is not known if SLE remains an independent risk factor for poor arthroplasty outcomes or if other factors, such as avascular necrosis (AVN), continue to play a role. METHODS: A case-control study using data from a single-institution arthroplasty registry compared SLE total hip arthroplasty (THA) and total knee arthroplasty (TKA) with OA controls matched by age, gender and presence of AVN. Baseline, two-year administrative and self-report data, and diagnosis leading to arthroplasty were evaluated. RESULTS: A total of 54 primary SLE THA and 45 primary SLE TKA were identified from May 2007 through June 2011. AVN was present in 32% of SLE THA and no TKA. SLE THA had worse preoperative WOMAC pain (42.5 vs. 52.7; p = 0.01) and function (38.8 vs. 48.0; p = 0.05) compared with OA. However, at two years there was no difference in WOMAC pain (91.1 vs. 92.1; p = 0.77) or WOMAC function (86.4 vs. 90.8; p = 0.28). SLE TKA were similar to OA in both preoperative pain (42.6 vs. 48.4; p = 0.14) and function (42.1 vs. 46.8; p = 0.30) and two-year pain (85.7 vs. 88.6; p = 0.50) and function (83.7 vs. 85.1; p = 0.23). Compared to OA, SLE THA and TKA patients had more renal failure (14% vs. 1%; p = 0.007) and hypertension (52% vs. 29%; p = 0.009). In a multivariate linear regression, SLE was not predictive of either poor pain or poor function. CONCLUSIONS: While SLE patients have more comorbidities than OA, and SLE THA have worse preoperative pain and function compared with OA controls, SLE was not an independent risk factor for poor short-term pain or function after either hip or knee arthroplasty.