Summary

This study assessed 41 patients undergoing meniscal allograft transplantation with up to 13 years of follow-up. MRI (MIMS, T2 mapping), extrusion, and alignment were analyzed. Tibial cartilage showed sustained protection; femoral hydration declined later. Despite structural wear, function remained stable in long-term follow-up, supporting MAT durability.

Abstract

This prospective study evaluated the long-term evolution of meniscal allografts in a cohort of patients using clinical scales, imaging, and mechanical alignment measures. From an ambispectively collected database, we analyzed 41 patients using magnetic resonance imaging T2 mapping (cartigram), extrusion measurements, mechanical axis deviation, and validated functional outcomes. Magnetic Resonance Imaging (MRI) appearance in Meniscal Transplant Scores (MIMS) declined significantly between follow-ups (p < 0.0001), and tibial cartilage hydration decreased over time. Patients reported a statistically significant reduction in pain (p = 0.0004), and coexisting anterior cruciate ligament rupture was associated with worse functional outcomes. Patients were followed from the date of surgery for up to 13 years. Tibial cartilage showed consistent protection, while femoral cartilage demonstrated early T2 relaxation time increases followed by partial recovery, then deterioration in the long term. Tibial cartilage hydration showed a more gradual decline, typically after 8 years. Structural degeneration (MIMS, extrusion) progressed over time but was not always associated with functional decline. In 13 patients with over 10 years of follow-up, function remained stable despite structural wear, suggesting MAT maintains chondroprotection.

Keywords: Meniscal injury, meniscal allograft transplantation, chondroprotection, meniscal extrusion.