Poor tibiofemoral congruity increases the risk of posterior cruciate ligament injury.

Abstract

Abstract Background Studies suggest that posterior cruciate ligament (PCL) injury may be related to the anatomical morphology of the distal femur and proximal tibia. Purpose In retrospectively, we studied whether there were differences in the morphology and correlation between the distal femur and proximal tibia between the PCL injury group and the age and sex matched PCL intact control group, and then found the risk factors for posterior cruciate ligament rupture. Methods From January 2015 to August 2022, 98 male patients with knee injury or discomfort due to non-contact mechanism were selected in the posterior cruciate ligament rupture group (n=49) and the posterior cruciate ligament intact group (n=49) by MRI images and arthroscopy. The posterior tibial slope (PTS), intercondylar notch width (INW), bicondyle width (BCW), angle of intercondylar notch (AIN), tibial spine width (TSW), and tibial platform width (TPW) were measured on X-ray and MRI coronal images, and the notch width index (NWI) was obtained by calculating the ratio of the intercondylar notch width to the bicondyle width, and the ratio of the tibial spine width to the tibial platform width was calculated to obtain the tibial eminence width index (TEWI). The ratio of the tibial spine width to the intercondylar notch width was calculated to obtain the tibiofemoral consistency index (TFCI) to describe the matching between the tibial spine and intercondylar notch. Results Univariate analysis showed that the posterior tibial slope, tibial spine width, tibial eminence width index, and tibiofemoral consistency index were lower than those in the posterior cruciate ligament rupture group (P < 0.05), and there was no significant difference in age, intercondylar notch width, bicondyle width, notch width index, angle of intercondylar notch and tibial platform width between the two groups (P > 0.05). Multivariate logistic regression analysis showed that the tibiofemoral consistency index was an independent risk factor for posterior cruciate ligament rupture (P < 0.05). The receiver operator characteristic curve (ROC curve) shows that the tibiofemoral consistency index has some predictive value for posterior cruciate ligament rupture, the area under the curve was 0.785, 95% CI (0.695, 0.875). Conclusions The tibiofemoral consistency index is an independent risk factor for posterior cruciate ligament rupture, and has a certain predictive value for posterior cruciate ligament rupture, and the lower the ratio, the worse the match between the tibial spine and the intercondylar notch, and the higher the risk of posterior cruciate ligament rupture.