Contact mechanics following medial meniscus posterior root tears and suture anchor repair in simulated gait: A cadaveric study

Medial Meniscus Posterior Root Tears (MMPRTs) are increasingly recognized, whereas research on contact mechanics associated with MMPRT during activities of daily living is limited. This study evaluated the effect of MMPRT on tibiofemoral pressure and the effectiveness of surgical repair during simulated gait. Eight fresh-frozen human cadaveric knees were tested using a joint motion simulator. Subject-specific loading profiles comprising seven key stages of the gait cycle were applied to (1) intact meniscus, (2) MMPRT, and (3) repair models. Contact pressure was measured at each stage using thin film pressure sensors beneath the menisci. The peak contact pressure (PCP), mean contact pressure (MCP), contact area (CA), and Dice similarity coefficient (DSC) that compares pressure distributions between conditions were evaluated. Compared to the intact condition, MMPRT caused significant differences in medial PCP, MCP, and CA, but only during the stance phase under the applied biomechanical model and loading conditions. Averaged across the stages within the stance phase, medial PCP and MPC were 32 % and 78 % higher, and CA was 35 % lower after MMPRT. After repair, these pressures generally remained significantly greater than their corresponding intact values. Specifically, medial PCP and MPC were on average 19 % and 40 % higher, and CA was 25 % lower than for the intact condition during the stance phase. DSCs relative to the intact state indicated that repair significantly improved pressure distributions (0.67–0.87) compared to MMPRT (0.47–0.78). The anatomic repair of MMPRT did not appear to fully restore intact contact pressure distributions in this study, suggesting that further improvement of surgical techniques may be beneficial.