A novel morphological classification for the femoral notch based on MRI: a simple and effective assessment method for the femoral notch.

Abstract

To propose a novel morphological classification method for notches, which may provide new evidence for notchplasty based on the three-dimensional (3D) features of notches and the risk of anterior cruciate ligament (ACL) injury. Three hundred individuals in total were included in our study, including 150 patients with ACL ruptures (75 males and 75 females) and 150 age- and gender-matched individuals without ACL ruptures. The notches were divided into four types according to the notch widths at the notch inlet, outlet, and ACL attachment based on the preoperative MRI, the notch volume was calculated, and the risk of ACL injury was compared. The surgical records were reviewed and whether these cases performed notchplasty were collected. The inlet-and-outlet stenosis notch type was associated with smaller notch volume (P = 0.007) and a higher risk of ACL injury (P <0.001). There were no significant differences in morphological distribution between males and females. The rate of notchplasty in inlet-and-outlet stenosis type was higher than the others. The new morphological classification method efficiently reflected the association of the notch shape with the 3D notch volume and the risk of ACL injury. The knees with the inlet-and-outlet stenosis notch type and smaller notch volume tended to have a higher risk of ACL injury. Level of evidence Level III, case-control study.