Summary

Lateral location of the tibial tunnel after single bundle anterior cruciate ligament reconstruction decreases the attachment area of the anterior lateral meniscus root.

Abstract

Introduction

The anterior lateral meniscal root (ALMR) has a role in functionally stabilizing the lateral meniscus. The tibial footprint of the anterior cruciate ligament (ACL) overlaps with the ALMR and there is a possibility that reaming of the tibial tunnel during ACL reconstruction may damage the ALMR attachment. The aim of this study was to investigate t loss of the attachment of anterolateral meniscal root after creating the tibial tunnel in single bundle anterior cruciate ligament reconstruction.

Methods

Eleven primary ACL-reconstructed patients with a mean age of 35.5 ± 11.7 years were included. The injured knees were scanned using high-resolution 3-T MRI. The attachment of ALMR was segmented from the images, and three-dimensional models were reconstructed to evaluate the morphology. The area, width and length of ALMR attachment were measured digitally. The values measured from pre- and post-operative MRI were compared using paired t-test. Correlations between the percentage of the loss of the area and the location of the tibial tunnel aperture, the width and length were evaluated.

Results

Pre- and post-operative values of the ALMR are as follows: mean area, 91.6 ± 5.9 mm2 and 73.8 ± 5.6 mm2 (p<0.0001); the width, 7.6 ± 0.3 mm and 5.8 ± 0.2 mm (p<0.0001); and the length, 9.8 ± 0.5 mm and 9.4 ± 0.5 mm (p=0.0039). The mean percentage of the attachment loss, reduction rate of the width and length were 19.7 ± 7.0%, 24.0 ± 8.3% and 4.4 ± 7.0%, respectively. The lateral border of the tibial tunnel aperture was 52.7 ± 2.2 % from the medial end of the tibia, and the posterior border of the aperture was 51.3 ± 2.9 % from the anterior end of the tibia. A positive correlation was observed between the percentage of the attachment loss and the location of the lateral border of the tibial tunnel aperture (r= 0.236), as well as the reduction rate of the attachment width (r=0.625).

Conclusions

The ALMR attachment was significantly decreased after creation of the tibial tunnel in single bundle anterior cruciate ligament reconstruction. More lateral location of the tibial tunnel appears to decrease the ALMR attachment area, implying damage to this structure. Such damage should ideally be avoided, requiring surgeons to have an awareness of this risk and to choose tunnel size and location judiciously.