Association Between Lateral Femoral Condyle Height and Depth Ratio, Medial Tibial Plateau Slope, and Isolated Posterior Cruciate Ligament Rupture.

Background: The morphological features of the femoral condyles have recently attracted attention as a potential risk factor for knee injuries. However, little is known about whether the femoral condylar morphology is related to posterior cruciate ligament (PCL) injury.

Purpose: To investigate whether the morphological characteristics of the femoral condyle are risk factors for isolated PCL rupture.

Study design: Case-control study; Level of evidence, 3.

Methods: From the patients who visited the outpatient clinic of our hospital between 2012 and 2022, we included 78 patients with isolated PCL ruptures and 78 age- and sex-matched controls with knee injury but no structural damage evident on magnetic resonance imaging (MRI). The following parameters were assessed using MRI: the lateral femoral condyle and medial femoral condyle height and depth ratio (LFC-H/D, MFC-H/D), notch width index, intercondylar notch angle, the lateral tibial plateau slope, and medial tibial plateau slope (MTPS), and medial tibial depth. Values were compared between these 2 groups using the independent t test and the Mann-Whitney U test. Univariate logistic regression analysis was subsequently performed to identify independent risk factors. Receiver operating characteristic curves were generated for the morphological indicators and the combination of risk factors.

Results: Patients in the isolated PCL rupture group had significantly lower LFC-H/D (0.49 vs 0.52; P < .001) and MTPS (7.34 vs 8.81; P = .012) values compared with the control group. In sex-specific analyses, both male and female patients with isolated PCL rupture had a significantly lower LFC-H/D (female patients: 0.46 vs 0.52; P < .001; male patients: 0.51 vs 0.52; P = .035). In addition, male patients with PCL rupture had a smaller MTPS (6.74 mm vs 8.79 mm; P = .004). Univariate logistic regression analysis further validated LFC-H/D (odds ratio [OR], <0.001; P < .001) and MTPS (OR, 0.889; P = .014) as risk factors for isolated PCL rupture.

Conclusion: A decreased LFC-H/D and a reduced MTPS were identified as risk factors for isolated PCL rupture. Sex-specific analysis further suggested that a decreased LFC-H/D was a risk factor for isolated PCL ruptures in both male and female patients, whereas a lower MTPS was a risk factor exclusively in male patients.