Variances of the intraarticular landmarks for anterior cruciate ligament tibial footprint: Tibial eminencies have less variability than lateral meniscus on sagittal magnetic resonance scans

Abstract

Objective: The purpose of this study was to analyze the sagittal plane variations of intraarticular landmarks for single bundle anterior cruciate ligament (ACL) reconstruction including lateral meniscus, medial and lateral tibial eminencies. Methods: T2 weighted sagittal magnetic resonance (MR) scans of 80 skeletally mature patients aged between 18 to 60 years and without any sign of ligament and meniscal injuries were viewed. Midpoint of ACL, most posterior aspect of anterior horn of lateral meniscus (LMAH), tip of medial eminence (ME) and lateral eminence (LE) were identified on widest antero-posterior (A-P) distance of tibial plateau according to of Staubli-Rausching method and variances were compared. Results: Mean location of center of tibial footprint of ACL at sagittal plane was found as 38.0±4.2% (range, 29-51%) on A-P distance of tibial plateau. Location of posterior border of LMAH, ME and LE were 38.0±12.4% (range, 21-62%), 52.3±4.2% (range, 41- 60%) and 59.5±4.4% (range, 51- 69%), respectively. Difference between the variances of ACL midpoint and LMAH was large enough to be statistically significant (p=<.001) with a large effect size (f=0.59), however differences between the variances of ACL midpoint and bony landmarks were not significant (ME, p=.65; LE, p=.33). Intra and interobserver agreement for measurement of all parameters were detected as moderate to good. Conclusion: There was no constant relationship between ACL midpoint and posterior border of LMAH on sagittal plane MR images. Difference of variances between ACL midpoint and ME and LE were significantly lower than of variances of LMAH.