Paper 33: Superior Improvements in Knee Pain and Function with a Novel Synthetic Medial Meniscus Replacement Prosthesis Compared to Non-surgical Care in Subjects with Knee Pain Following Partial Meniscectomy: Three-year Results from US Randomized Controlled Trial

OBJECTIVES: This study tests the hypothesis that subjects receiving the meniscus replacement prosthesis show superior improvements at 3 years with regards to knee-related pain, function, and quality of life compared to control subjects, through 3 years of follow-up. METHODS: 127 subjects (61 investigational, 66 control) were included in the multicenter RCT. Subjects had one or more partial meniscectomies at least 6 months before trial entry and continued to have pain. Patient-reported knee pain, function, and quality of life were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS). Treatment failure was defined as any investigational subject who discontinued the per-protocol treatment by permanent prosthesis removal, or control subjects undergoing any surgical procedure on the index knee. Standard statistical methodology was used, two tailed t-test was used to compare groups at each time point. RESULTS: Both groups improved over 24 months, but the control group showed a significant drop at 3 years. Controls experienced a 35% decline in KOOS Overall improvement between the 2-year and 3-year timepoint (15.9 declined to 10.4). The treatment group continued to improve over 3 years. The treatment group had significantly better outcomes scores that were greater than MCD for all KOOS subscales at 3 years (Figure 1). KOOS Overall and KOOS Pain for the investigational and control cohorts at 3 years were 28.8 vs 10.4 points, and 29.7 vs 15.4 points, respectively. Treatment cessation through 3 years was 67% greater in the control cohort than the investigational cohort (11.5% vs. 19.2%). CONCLUSIONS: Patients receiving the meniscal replacement prosthesis had clinically meaningful improvement of their patient reported outcomes scores at 3 years. These improvements were superior to the control treatment. The improvements were maintained over three years, whereas the control group declined after 2 years. The magnitude of change from baseline to 3 years remained superior for the investigational cohort, even for subjects undergoing device exchange or repositioning, compared to non-surgical care subjects.