Extensor Mechanism Reconstruction with Use of Marlex Mesh: A Series Study of 77 Total Knee Arthroplasties

Disruption of the extensor mechanism after total knee arthroplasty (TKA) is debilitating, and the reported results of numerous reconstructive options have varied. We previously reported the early results of 13 patients who underwent reconstruction of the extensor mechanism with use of Marlex mesh. The purpose of the current study was to assess results in a larger cohort of patients, with an emphasis on the survivorship of the mesh, clinical results, and complications.

During the period of 2000 to 2015 at a single tertiary care academic institution, 77 patients (77 TKAs) underwent reconstruction with use of Marlex mesh for an extensor mechanism disruption (27 quadriceps tendon disruptions, 40 patellar tendon disruptions, and 10 patellar fractures). The mean patient age at the time of reconstruction was 65 years; 70% of the patients were female. The mean body mass index was 35 kg/m. The mean follow-up was 4 years. Eighteen (23%) of the patients underwent mesh reconstruction with the primary TKA in place, and 59 (77%) had mesh reconstruction at the time of revision TKA. The mean time between disruption and reconstruction was 7 months. Twenty (26%) of the patients had previously undergone attempted extensor mechanism reconstruction at outside institutions.

Sixty-five of the 77 mesh reconstructions were in place at the time of the latest follow-up. Twelve patients experienced a failure that required mesh revision: 5 for patellar tendon rupture, 5 for quadriceps tendon rupture, and 2 for symptomatic lengthening. Four additional patients with mesh failure were treated nonoperatively with bracing. The 2-year survivorship free of mesh revision was 86% for patients with no prior reconstruction and 95% for patients with previous reconstructions of the extensor mechanism that did not involve Marlex mesh. Knee Society Score (KSS) results significantly improved following reconstruction (p < 0.001). Extensor lag improved by a mean of 26°, with mean postoperative extensor lag measuring 9° (p < 0.001).

Reconstruction of the extensor mechanism with use of Marlex mesh is a viable option in patients with catastrophic disruption after TKA. At the time of the latest follow-up, 84% of the mesh reconstructions were in place and the functional outcomes were excellent, with mean improvement in extensor lag of 26°. Extended follow-up is required, but the results of this large series with a mean follow-up of 4 years are encouraging.

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.