Outcomes of two-stage total knee arthroplasty following septic arthritis of the native knee: A propensity score-matched analysis.

Abstract

To compare the functional outcomes and complications between two-stage total knee arthroplasty (TKA) performed in patients with native knee joint infection and TKA performed in patients with osteoarthritis (OA). This was a retrospective study of 25 patients (25 knees, septic arthritis group) who underwent two-stage TKA for septic arthritis of the native knee joint between 2013 and 2021. Through 1:3 propensity score matching for age, sex, body mass index, follow up duration, and American Society of Anesthesiologists (ASA) score, 75 cases of TKA performed for OA (OA group) were included in the control group. Radiological and functional outcomes and complication rates were compared between the two groups. There was no significant difference in radiological outcomes between the two groups. Preoperative range of motion (ROM) (72.8 ± 23.8 vs. 128.0 ± 7.2, P < 0.001) and all preoperative patient-reported outcomes (P < 0.05) in the septic arthritis group were inferior compared with the OA group. The postoperative ROM (112.0 ± 15.7 vs. 132.3 ± 7.3, P < 0.001) and patient-reported outcomes (all parameters, P < 0.05) were also inferior in the septic arthritis group. The incidence of periprosthetic joint infection (three cases vs. none, P = 0.014) and the reoperation rate (four cases vs. one case, P = 0.013) were significantly higher in the septic arthritis group. Two-stage TKA for septic arthritis of the native knee joint showed relatively good infection control and functional outcomes. However, it was associated with a higher risk of periprosthetic joint infection and poorer functional outcomes compared with TKA performed for OA.