Poster 242: Predictors of the Ten-Year Patient-Reported Outcome Measures After Collagen Meniscus Implant (CMI) for Partial Meniscus Deficiency

OBJECTIVES: Collagen Meniscus Implant (CMI) is considered an effective procedure for reducing knee pain and improving knee function after previous meniscectomy. Nevertheless, the current knowledge regarding the clinical results of CMI are limited to small case series at short- to mid-term follow-up studies. The goal of the present study was to evaluate clinical outcomes, reoperations, and failures of CMI at a minimum 10 years of follow-up. METHODS: Consecutive patients who underwernt CMI at a single institution were screened for elegibility. Inclusion criteria for the present study were (1) Medial or Lateral CMI, (2) Isolated or combined procedure with ACL reconstruction, knee osteotomy or cartilage treatment, (3) follow-up between 10 and 15 years. Demographics and surgical details were obtained via chart review. Patients were asked if they were satisfied with the procedure and were evaluated with the Lysholm score, Knee injury and Osteoarthritis Outcome Score (KOOS), visual analog scale (VAS) for pain, and Tegner score at the final follow-up. Survival analysis was performed with Kaplan-Meier curve, and clinical scores were analyzed based on the Patient Acceptable Symptom State (PASS). RESULTS: A total of 92 patients (mean age, 42.8 years) were included in the analysis. A significant improvement in all the clinical scores was reported between the preoperative evaluation and the last follow-up. A chondropaty with outerbridge grade ≥III was associated with significantly overall lower clinical score, while a timing from meniscectomy to CMI implant to ≥5 years determined more pain at rest and lower score in the KOOS quality of life. Overall, 25% of patients did not achieved the PASS for Lysholm score and a percentage variable from 19% (KOOS Pain) and 40% (KOOS Symptoms) did not achieved the PASS in the KOOS subscales. Chondropaty with outerbridge grade ≥III was associated with an higher Risk of not achieving the PASS in all the KOOS subscales, while an age at surgery ≥45 years was resulted in a lower risk of not achieving PASS in the pain subscale. At the last follow-up 63% of patients returned to sport practice after CMI implantation, with 41% at the same or higher level. Finally, 80% of the patients were satisfied with the procedure CONCLUSIONS: CMI provided satisfactory results in terms of function, symptoms, sports and quality of life in 60% to 80% of the patients after more than 10 years of follow-up with clinical scores still higher compared to the preoperative evaluation. The cartilage status and the time from meniscectomy have shown to impact negatively on the outcomes, while an age >45 years was associated with less pain.