Two-Stage Exchange and Marlex-Mesh Reconstruction for Infection with Extensor Mechanism Disruption After Total Knee Arthroplasty

Background: Periprosthetic joint infection (PJI) of the knee with concurrent disruption of the extensor mechanism is a devastating complication. Historically, knees with such complications have been salvaged with use of an arthrodesis or amputation. The purpose of this study was to assess the survival and functional outcomes of a 2-stage exchange arthroplasty combined with knitted monofilament polypropylene (Marlex; C.R. Bard) mesh reconstruction of the extensor mechanism. Methods: From 2000 to 2015, 16 patients underwent a 2-stage exchange arthroplasty and Marlex-mesh reconstruction for PJI with an extensor mechanism disruption. The study included 9 male patients and 7 female patients with a mean age at the time of reimplantation and mesh reconstruction of 64 years. The mean follow-up was 4 years. PJI was diagnosed on the basis of the Musculoskeletal Infection Society criteria. Clinical outcomes, including survivorship, Knee Society Score (KSS) results, and complications, were assessed. Results: Of 16 reconstructions, 13 were in place at the time of the latest follow-up. At 2 years, survivorship free of mesh failure was 86%, survivorship free of PJI was 87%, and survivorship free of PJI or mesh failure was 75%. The mean KSS improved from 48 prior to resection to 74 after mesh reconstruction and reimplantation. The mean extensor lag improved from 31 degrees prior to resection to 3 degrees after mesh reconstruction. Two patients required mesh revision, 1 patient required an above-the-knee amputation for complex wound complications related to reinfection, 1 patient developed a reinfection requiring irrigation and debridement, and 1 patient developed a superficial infection that required debridement. Conclusions: Two-stage exchange arthroplasty combined with Marlex-mesh reconstruction of the extensor mechanism is a viable alternative to knee arthrodesis or amputation. At 2 years, 75% of mesh reconstructions were in place and without evidence of PJI. Moreover, the functional outcomes were improved, with a negligible extensor lag.