Purpose

To evaluate the in-vivo knee laxity in presence of a partial medial meniscectomy before and after a Single-Bundle ACL reconstruction with the addition of a lateral plasty (SBLP) and to compare it with the knee laxity after a Single-Bundle ACL reconstruction (SB).

Methods

101 patients with ACL tear were included in the study and grouped according to the surgical technique and the meniscus treatment: regarding the SBLP technique (n=55), 31 patients underwent isolated ACL reconstruction (“SBLP Isolated ACL Group”), while 24 patients underwent combined ACL reconstruction and partial medial meniscectomy (“SBLP ACL+MM Group”); regarding the SB technique (n=46), 33 patients underwent isolated ACL reconstruction (“SB Isolated ACL Group”), while 13 patients underwent combined ACL reconstruction and partial medial meniscectomy (“SB ACL+MM Group”). Anterior-Posterior clinical laxity at 30° (AP30) and 90° (AP90) of knee flexion were quantified before and after surgery through a surgical navigation system dedicated to kinematic assessment.

Results

In the ACL-deficient status, the antero-posterior laxity was significantly higher in presence of a combined MM in both the AP30 and the AP90, with no differences between the two surgical techniques. After the ACL reconstruction, both AP30 and AP90 translations decreased significantly (p<0.0001) compared to the ACL-deficient status. No differences were found for AP30 and AP90 between SBLP Isolated ACL and SBLP+MM groups, while a significantly higher AP90 translation was found for the SB+MM group compared to the SB Isolated ACL group. Moreover, the AP90 translation in the SB ACL+MM group was significantly higher than the one of the other three groups, i.e., SBLP ACL+MM, SB, and SBLP Isolated ACL group.

Conclusion

The addition of a lateral plasty compensated the effect of a medial meniscectomy on AP knee laxity in the context of an ACL surgery.