Abstract
Introduction
Anatomical reconstruction of the Anterior Cruciate Ligament (ACL) reconstruction has been shown to be desirable and improve patient outcome. The posterior border of the anterior horn of the lateral meniscus (AHLM) is an easily identifiable arthroscopic landmark, which could guide anatomic tibial tunnel position in the sagital plane. The aim of the study was to establish the relationship between the posterior border of AHLM and the centre of the ACL foot print to facilitate anatomical tibial tunnel placement.
Materials/Methods
We analysed 100 knee MRI scans where there was no ACL or lateral meniscal injury. We measured the distance between the posterior border of the AHLM and the midpoint of the tibial ACL footprint in the sagital plane. The measurements were repeated 2 weeks later for intra-observer reliability.
Results
The mean distance between the posterior border of the AHLM and the ACL midpoint was −0.1mm (i.e. 0.1mm posterior to the ACL midpoint). The range was 5mm to −4.6mm. The median value was 0.00mm. 95% confidence interval was from 0.3 mm to −0.5 mm. A normal, parametric distribution was observed and Intra-observer variability showed significant correlation (p=0.01) using Pearsons Correlation test.
Conclusion
Using the posterior border of the AHLM is a reliable, reproducible and anatomic marker for the midpoint of the ACL footprint in the majority of cases. It can be used intra-operatively as a guide for tibial tunnel and graft placement allowing anatomical reconstruction. There will inevitably be some anatomical variation. Pre-operative MRI assessment of the relationship between AHLM and ACL footprint is advised to improve surgical planning.
