Functional outcomes of one-stage arthroplasty for native septic knee arthritis: a matched case-control study versus...

To investigate the short-term outcomes of one-stage total knee arthroplasty (TKA) for native septic arthritis of the knee concomitant with osteoarthritis (OA), and to compare these outcomes with those of matched patients undergoing primary TKA for isolated OA during the same period.

This retrospective study included 11 patients treated between January 2020 and January 2024 for native septic knee arthritis with concomitant OA who underwent one-stage TKA (one-stage group). A contemporaneous control cohort of 33 patients with isolated OA undergoing primary TKA (OA-only group) was selected using individualized 1:3 matching. Perioperative variables, Knee Society Score (KSS), and visual analog scale (VAS) pain scores were compared between groups.

Over a 2-year postoperative follow-up, the infection control rate in the one-stage group was 90.9% (10/11). One patient experienced recurrent postoperative infection, which was controlled after debridement and targeted antimicrobial therapy with implant retention. Postoperatively, KSS clinical and function scores improved significantly and VAS pain scores decreased significantly compared with preoperative values (all P < 0.001). Compared with the OA-only group, there were no significant differences in postoperative KSS clinical score, KSS function score, or VAS score (all P>0.05). However, operative time, intraoperative blood loss, and postoperative length of stay were significantly greater in the one-stage group (all P < 0.001). The overall complication rate did not differ significantly between groups (P = 0.812).

In carefully selected patients with native septic knee arthritis concomitant with OA, one-stage TKA may provide substantial functional improvement with a high rate of infection control. Short-term clinical outcomes appear comparable to those of primary TKA for isolated OA, although the perioperative burden is higher.