Treatment with posterior capsular release, botulinum toxin injection, hamstring tenotomy, and peroneal nerve decompression improves flexion contracture after total knee arthroplasty: minimum 2-year follow-up

Purpose No definite treatment option with reasonable outcome has been presented for old and refractory flexion contracture after total knee arthroplasty (TKA). We describe a surgical technique for 21 refractory cases of knee flexion contracture, including 12 patients with history of failed manipulation under anesthesia (MUA). Methods Retrospective review was conducted for procedures performed by a single surgeon between 2005 and 2016. Twenty-one knees (19 patients) with knee flexion contracture after primary TKA were treated with all the following procedures: posterior capsular release, hamstring tenotomy, prophylactic peroneal nerve decompression, and botulinum toxin type A injections. Twelve of the 21 knees had at least 1 prior unsuccessful MUA before this soft-tissue release procedure. Mean age at intervention was 60 years (range 46–78 years). Mean preoperative knee range of motion (ROM) was – 27° extension (range – 20° to – 40°) to 100° flexion (range 90°–115°). All radiographs were evaluated for proper component sizing and signs of loosening. Results Full extension was achieved immediately after surgery in all patients. Only one knee required repeat botulinum toxin type A injection. All patients had full extension at mean follow-up of 31 months (range 24–49 months). No significant change was observed in knee flexion after the procedure (n.s.). Significant improvement was noted in the postoperative Knee Society Score (KSS) (mean 80, range 70–90) when compared with preoperative KSS (mean 45, range 25–65) ( p = 0.008). Conclusion The proposed surgical technique is efficacious in treating patients with refractory knee flexion contracture following TKA to gain and maintain full extension at minimum 2-year follow-up. Level of evidence IV, retrospective case series.