Lateral Meniscal Allograft Transplantation Provides a Chondroprotective Effect on Articular Cartilage: Quantitative 3-T Magnetic Resonance Imaging T2 Mapping

Abstract

This study aimed to assess the cartilage status in patients who underwent isolated lateral meniscus allograft transplantation (MAT) using preoperative and postoperative quantitative 3-T magnetic resonance imaging (MRI) T2 mapping at midterm follow-up period. Patients who underwent lateral MAT without cartilage treatment procedures between 2010 and 2019 were assessed by quantitative MRI preoperatively and postoperatively. On the sagittal section image following the center of the lateral femoral condyle, the weightbearing area of the articular cartilage was divided into six segments based on the meniscal coverage area from anterior to posterior direction. The mean T2 values of each six segments were measured for three regions of interest: overall, deep, and superficial layers. The change in T2 values was statistically analyzed by paired t-tests. The Lysholm score was used to evaluate clinical function. A total of 105 patients were included in the study. The mean follow-up period was 3.2 years (range, 2.0-5.4 years). Among the six segments, the mean T2 value showed significant improvement in the overall layer of F2 (the middle weightbearing area of femoral condyle) and TP3 (the posterior weightbearing area of tibia condyle) segments (P = .013 and .021, respectively) and the superficial layer of the F3 (the posterior weightbearing area of femoral condyle) segments (P = .028). The mean T2 value of all the other segments did not show statistically significant change. The mean Lysholm score significantly improved from 66.5±15.8 to 89.3±10.0 (P <.001). Overall, 73.3% and 96.2% of the patients met MCID and PASS respectively. The mean T2 value of the articular cartilage of the weightbearing area was either maintained or showed statistically significant improvement depending on the location following isolated lateral MAT. Thus, the transplanted meniscus seems to have the chondroprotective effect on the weightbearing cartilage. Level IV, retrospective therapeutic case series.