Long-Term Results of Meniscus Allograft Transplantation With Bone Fixation Show Improved Outcomes but Progression of Joint Space Narrowing, Osteoarthritis, and Cartilage Degeneration

To investigate the clinical and objective outcomes of meniscal allograft transplantation (MAT) using bone fixation in patients after a minimum follow-up duration of 15 years and to compare the demographic factors and allograft status between patients who experienced progression of osteoarthritis and those who did not. Consecutive patients who underwent primary MAT between December 1996 and January 2008 were reviewed retrospectively. The inclusion criterion was primary MAT with a minimum follow-up duration of 15 years. Clinical outcomes were evaluated using the modified Lysholm score, along with an evaluation of clinical failure. In objective outcomes, the progression of joint space narrowing, osteoarthritis, and the status of the associated cartilages and allografts were evaluated with follow-up radiographs and magnetic resonance imaging. Among the 79 cases, 54 knees in 52 patients were included in the study and evaluated for clinical outcomes. The mean Lysholm score improved from 73.9 ± 17.5 preoperatively to 86.4 ± 15.6 over a mean follow-up period of 17.5 ± 3.8 years (P < .001). Regarding minimal clinically important differences, 38 cases (70.4%) showed an improvement in the Lysholm score. The cumulative clinical survival rate was 87.0%. Objective evaluations evaluated in 32 cases with a minimum of 15 years of radiographic data revealed significant progression of joint space narrowing, osteoarthritis, and cartilage degeneration at the final follow-up, with 11 (34.4%) of 32 cases exhibiting allograft tears involving ˃50% of the allograft. Patients with progression of osteoarthritis exhibited more meniscal allograft tears and extrusion on the last follow-up magnetic resonance imaging scans than those without progression. Notable progression in joint space narrowing, osteoarthritis, and cartilage degeneration were observed in objective assessment. The progression of osteoarthritis might be associated with allograft tears and extrusion. In clinical evaluations, favorable long-term clinical outcomes were consistently demonstrated after MAT using the bone fixation technique. Level Ⅳ, therapeutic case series.