Synthetic Mesh Allograft Reconstruction for Extensor Mechanism Insufficiency After Knee Arthroplasty

Extensor mechanism (EM) insufficiency after knee arthroplasty is a rare but devastating complication resulting in severe disability. To date, primary repair and allograft reconstructive options have produced suboptimal results. A synthetic mesh allograft reconstruction technique has recently been introduced with promising outcomes. A retrospective chart review was performed to identify all patients who experienced EM failure after total or unicompartmental knee arthroplasty and subsequently underwent synthetic mesh EM reconstruction using a previously described technique. Patient demographics, pre- and postoperative knee range of motion and residual extensor lag, pre- and postoperative pain and functional outcome scores, and complications were extracted during the chart review. Twelve patients met inclusion criteria: 3 with patellar tendon and 9 with quadriceps tendon defects. At mean follow-up of 27.0 months, all patients were ambulatory, with a mean residual extensor lag of 12.9° (range, 0°–30°). Mean visual analog scale pain score decreased significantly after EM reconstruction: 4.6±2.3 (range, 1–8) preoperatively vs 1.8±2.4 (range, 0–7) postoperatively ( P =.01). The mean Knee Society knee score improved from 41.5±11.1 (range, 21–57) preoperatively to 79.5±13.8 (range, 54–90) postoperatively ( P P Orthopedics. 2019; 42(4):e385–e390.]