The optimal surgical treatment for posteromedial meniscal root tears, a debilitating injury, is controversial. While many agree that the reduction of the meniscus to the native ?anatomic? position is required to restore function, this can be technically challenging to implement. As a result, meniscal root repairs are often reduced in various nonanatomic locations on the tibia, the functional consequences of which are poorly understood. We have previously shown that during simulated walking, some knees are ?meniscal loaders?, while others bypass the meniscus and place higher focal forces on areas of cartilage-to-cartilage contact. We ask the question: are some knees more sensitive to meniscal root repair position than others? Our overall objective is to evaluate the biomechanical effects of position on posteromedial meniscal root repairs under dynamic loading conditions. Our central hypothesis is that there is a knee-dependent ?safe zone? for the repair position of posterior medial meniscal root tears, which will minimize changes in joint mechanics during level walking. To test our central hypothesis, we have developed two aims that harness the strengths of both cadaveric and computational modeling approaches.
Specific Aim 1 : Investigate joint contact stress throughout level walking after medial nonanatomic root repairs. We will use a cadaveric model to quantify changes in contact mechanics and kinematics after anatomic and nonanatomic repairs for posteromedial meniscal root tears during simulated stair climbing and level walking. We will test the hypotheses that: (1) anatomic root repairs will restore joint contact mechanics to intact during level walking better than nonanatomic medial root repairs (2) both repairs will restore contact mechanics to intact better than untreated root tears.
Specific Aim 2 : Quantify the effect of meniscal root repair position on joint mechanics during level walking. The data generated in SA1 will be used to create validated finite element models, where more precise control over the variation in attachment position is possible. We will test the hypothesis that there is a knee-dependent ?safe zone? for the position of posteromedial meniscal root repairs, which can restore the distribution of contact stress to that of the intact condition during level walking. By combining the data generated from SA1 and SA2, we aim to develop new clinical guidelines for the ideal position of meniscal root repairs to restore joint function.
This project aims to provide clinical guidelines for the optimal position for the repair and reattachment of meniscal root tears. We will integrate physical and computational models to measure the effects of simulated repairs. This approach will enable us to identify a 'safe zone' for repairs, where the repair position returns contact mechanics to normal.
