Outcomes and Predictors of Success for Arthroscopic Lysis of Adhesions for the Stiff Total Knee Arthroplasty

A stiff total knee arthroplasty (TKA) can manifest as pain and decreased range of motion (ROM). When conservative management including physical therapy and manipulation under anesthesia fails, arthroscopic lysis of adhesions (LOA) is frequently pursued. The authors examined the efficacy of LOA for the stiff TKA. They retrospectively reviewed the records of 18 patients who underwent LOA for stiff TKA between April 2013 and June 2016 and who failed to meet 90 degrees ROM at 6 weeks postoperatively. They recorded patient demographics, ROM prior to TKA, and incidence of manipulation under anesthesia between initial TKA and LOA as well as pre-and postoperative outcomes of ROM, pain, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. The mean time from TKA to LOA was 117 days, with a mean follow-up of 449 days. Mean improvements in ROM flexion contracture, flexion, and arc were 6.11 degrees (P<.05), 29.45 degrees (P<.001), and 35.56 degrees (P<.001), respectively. Range of motion improved for 17 of 18 patients. The WOMAC was completed by 15 of 18 patients, with a mean improvement in scores of 32.23% (P<.001); all 15 patients with available WOMAC scores improved. Pain score improved by a mean of 2.17 (P<.001), with 14 of 18 patients reporting decreased pain. Improvements in flexion contracture, flexion, ROM arc, WOMAC scores, and pain were all statistically significant (P<.05). Age, weight, body mass index, and time to LOA were found to be statistically significant predictors of outcome. Finally, pre-TKA and pre-LOA ROM parameters were found to be statistically significant predictors of post-LOA ROM outcomes.