Two-Year Clinical Results of Lateral Collagen Meniscus Implant: A Multicenter Study

Purpose: To present the 2-year results of the use of the lateral Collagen Meniscus Implant (CMI) for the treatment of irreparable lateral meniscal lesions or partial lateral meniscal defects, to investigate the potential predictors of clinical results, and to monitor device safety. Methods: Forty-three patients with a mean age of 30.1 +/- 12.0 years were clinically evaluated 24 months after treatment of partial lateral meniscal defects with the CMI (Ivy Sports Medicine, Grafelfing, Germany). We used the Lysholm score, the Tegner Activity Scale, a visual analog scale for pain (during strenuous activity, during routine activity, and at rest), a functional questionnaire, and a satisfaction questionnaire for the evaluation. All demographic and surgical parameters were used for multiple regression analysis to find outcome predictors. Serious adverse events and reoperations were monitored. Results: All clinical scores significantly improved from preoperatively to final evaluation at 24.2 +/- 1.9 months' follow-up. The Lysholm score improved significantly from 64.3 +/- 18.4 preoperatively to 93.2 +/- 7.2 at final follow-up (P = .0001). Functional improvement was detected from 6 months after surgery, whereas strenuous activities and knee swelling reached optimal results after 12 months. The highest pain ratings experienced during strenuous activity, during routine activity, and at rest significantly improved from 59 +/- 29, 29 +/- 25, and 20 +/- 25, respectively, preoperatively to 14 +/- 18, 3 +/- 5, and 2 +/- 6, respectively, at 2 years' follow-up (P = .0001). At final follow-up, 58% of patients reported activity levels similar to their preinjury values whereas 95% of patients reported that they were satisfied with the procedure. A higher body mass index, the presence of concomitant procedures, and a chronic injury pattern seemed to negatively affect the final outcomes. Serious adverse events with a known or unknown relation to the scaffold, such as pain, swelling, and scaffold resorption, were reported in 6% of patients, leading to CMI explantation, debridement, or synovectomy. Conclusions: The lateral CMI scaffold could be considered a potentially effective and safe procedure to treat both irreparable lateral meniscal tears and post-meniscectomy syndrome in appropriately selected patients. Chronic injury, high body mass index, and concomitant procedures have been shown to negatively affect the short-term results; however, the results appeared to slowly improve through the 24-month follow-up period. Thus patience is needed when evaluating the expectations for and results of the described procedure.