Prospective long-term outcomes of the medial collagen meniscus implant versus partial medial meniscectomy: a minimum 10-year follow-up study

Background: Loss of meniscal tissue can be responsible for increased pain and decreased function. Hypothesis: At a minimum 10-year follow-up, patients receiving a medial collagen meniscus implant (MCMI) would show better clinical, radiological, and magnetic resonance imaging (MRI) outcomes than patients treated with partial medial meniscectomy (PMM). Study design: Cohort study; Level of evidence 2. Methods: Thirty-three nonconsecutive patients (men; mean age, 40 years) with meniscal injuries were enrolled in the study to receive MCMI or to serve as a control patient treated with PMM. The choice of treatment was decided by the patient. All patients were clinically evaluated at time 0 and at 5 years and a minimum of 10 years after surgery (mean follow-up, 133 months) by Lysholm, visual analog scale (VAS) for pain, objective International Knee Documentation Committee (IKDC) knee form, and Tegner activity level scores. The SF-36 score was performed preoperatively and at final follow-up. Bilateral weightbearing radiographs were completed before the index surgery and at final follow-up. Minimum 10-year follow-up MRI images were compared with preoperative MRI images by means of the Yulish score. The Genovese score was also used to evalute MCMI MRI survivorship. Results: The MCMI group, compared with the PMM one, showed significantly lower VAS for pain (1.2 ± 0.9 vs 3.3 ± 1.8; P = .004) and higher objective IKDC (7A and 10B for MCMI, 4B and 12C for PMM; P = .0001), Teger index (75 ± 27.5 vs 50 ± 11.67; P = .026), and SF-36 (53.9 ± 4.0 vs 44.1 ± 9.2; P = .026 for Physical Health Index; 54.7 ± 3.8 vs 43.8 ± 6.5; P = .004 for Mental Health Index) scores. Radiographic evaluation showed significantly less medial joint space narrowing in the MCMI group than in the PMM group (0.48 ± 0.63 mm vs 2.13 ± 0.79 mm; P = .0003). No significant differences between groups were reported regarding Lysholm (P = .062) and Yulish (P = .122) scores. Genovese score remained constant between 5 and 10 years after surgery (P = .5). The MRI evaluation of the MCMI patients revealed 11 cases of myxoid degeneration signal: 4 had a normal signal with reduced size, and 2 had no recognizable implant. Conclusion: Pain, activity level, and radiological outcomes are significantly improved with use of the MCMI at a minimum 10-year follow-up compared with PMM alone. Randomized controlled trials on a larger population are necessary to confirm MCMI benefits at long term.