Extensor Mechanism Reconstruction Following Periprosthetic Joint Infection After Total Knee Arthroplasty: A Systematic Review.

Periprosthetic joint infection (PJI) with concomitant extensor mechanism disruption (EMD) following total knee arthroplasty (TKA) is a rare but devastating complication associated with severe functional loss and limited limb-salvage options. Although several reconstructive strategies have been described, outcomes in the infected setting remain poorly defined. We conducted a systematic review, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, to evaluate the reconstructive approaches and reported clinical outcomes for EMD in the setting of PJI after TKA. PubMed and Semantic Scholar were searched from inception through January 31, 2026, for studies reporting outcomes after extensor mechanism reconstruction in patients with PJI following TKA; primary clinical studies and systematic reviews were eligible. Extracted variables included reconstructive technique, failure and reinfection rates, functional outcomes, and follow-up duration. Eleven studies met the inclusion criteria, comprising three primary clinical studies and eight systematic reviews or meta-analyses. Reported failure rates varied across the included literature, and no formal comparison established superiority or equivalence of allograft versus synthetic mesh reconstruction. Reconstruction was associated with meaningful functional improvement: postoperative Knee Society Scores frequently exceeded 70 points, extensor lag typically improved to less than 10°, and postoperative flexion generally ranged from 95° to 110°. Recurrent infection remained an important cause of treatment failure in the PJI-specific literature. Extensor mechanism reconstruction after PJI complicating TKA remains a complex limb-salvage procedure with a guarded prognosis; reported outcomes appear to depend on infection control, soft-tissue quality, and defect-specific reconstructive planning.