Summary

The presence of medial meniscus tear significantly altered knee kinematics in the context of ACL injury. The meniscal repair does not restore the tibial internal rotation of an isolated ACL reconstruction.

Abstract

Purpose

The in-vivo biomechanical role of meniscal lesions in combination with Anterior Cruciate Ligament (ACL) injury has not been extensively investigated. The aim of the present study was to quantify the effect of medial meniscus injury and subsequent repair in the context of ACL injury and reconstruction on the in-vivo active knee kinematics.

Methods

Nineteen patients with ACL injury were included: 10 had intact menisci (IM group) and 9 had medial meniscus injury (meniscus repair – MR group). The ACL reconstruction was performed either with Anatomic Single Bundle or Over-the-top plus lateral plasty technique using hamstrings, while medial meniscus lesions were repaired with an all-inside technique. Active knee kinematics under weight-bearing conditions was evaluated using a dynamic biplane radiographical system (roentgen stereophotogrammetric analysis – RSA) during a single-leg squat, performed preoperatively and 18 months after ACL reconstruction. The General Linear Model was used to investigate the differences in terms of groups (IM vs MR) and time (preoperative vs follow-up) and their interactions (p<0.05).

Results

Tibial internal rotation was higher in the MR group with respect to the IM group both before and after surgery (p<0.007). Knee valgus was higher in the MR group preoperatively (p<0.001), while no differences were found at follow-up. Preoperatively, the IM group showed a more medial tibia compared to the MR group in the descendant phase (p<0.006).

Conclusion

The presence of medial meniscus tear significantly altered knee kinematics in the context of ACL injury. The meniscal repair does not restore the tibial internal rotation of an isolated ACL reconstruction.