Effect of Meniscocapsular and Meniscotibial Lesions in ACL-Deficient and ACL-Reconstructed Knees: A Biomechanical Study
The medial meniscus is connected to the knee joint capsule at the meniscocapsular attachment (MCA) and to the tibia at the meniscotibial attachment (MTA). Tears of the MCA, historically termed “ramp” lesions” have been reported in up to 17% of anterior cruciate ligament (ACL) tears. However, debate exists over whether ramp lesions are due to tears of the MCA or MTA. Through use of cadaver knees and a robot that controlled flexion of the knee, this study aimed to determine the impact of MCA and MTA injuries on stability in knees with ACL injury and ACL reconstruction.
Isolated or combined MCA and MTA injury led to increased instability in knees with ACL injury in all directions tested. When the ACL was reconstructed after combined MCA and MTA injury, knee stability in the forward direction was restored but not with respect to internal or external rotation of the knee. Rotational stability was only restored at lower flexion angles after repairing ACL, MCA, and MTA. In summary, this study suggests that we should be on the lookout for meniscal ramp lesions in the setting of ACL injury and that these lesions should be repaired at the time of ACL reconstruction to improve knee stability.
Figure 5. Illustration of the tear locations for the meniscocapsular and meniscotibial attachments. MCA, meniscocapsular attachment; MTA, meniscotibial attachment.