Correlation of Anterior Cruciate Ligament Tear with Femoral Trochlear Dysplasia and Patellar Position.

Objectives: To evaluate the correlation of anterior cruciate ligament (ACL) tear with femoral trochlear dysplasia (FTD) and patella position based on MRI, aiming to identify anatomical risk factors for ACL injuries.

Methods: 190 patients with ACL tear conformed by arthroscopy underwent preoperative MRI were retrospectively reviewed in the study from September 2019 to July 2023, and 190 control subjects without ACL tear were collected. Femoral trochlear morphology indicators {including trochlear sulcus depth (TSD), trochlear sulcus lateral facet ratio (TSLFR), and trochlear sulcus angle (TSA)} and patellar position indicators {including patellar cartilage-to-tibial tuberosity distance (PCTD), length of patellar articular surface (LPAS), and Modified Insall-Salvati (MIS) index}were analyzed.

Results: The ACL tear group had a lower average age (27.72 ± 7.55 years) compared to the normal group (30.30 ± 6.62 years, P＜0.001) and a higher proportion of males (75.3% vs. 24.7%, P = 0.011). Anatomically, the ACL tear group exhibited a shallower TSD (3.73 ± 1.03 mm vs. 4.33 ± 0.91 mm) and a larger TSA (153.33 ± 6.62° vs. 145.82 ± 4.94°, P < 0.001), while no significant difference was observed in the TSLFR. The PCTD (50.83 ± 6.28 mm vs. 47.33 ± 6.42 mm) and MIS index (1.74 ± 0.23 vs. 1.64 ± 0.15, P < 0.001) were higher in the ACL tear group. Binary logistic regression identified male gender, FTD, and patella alta as independent predictors of ACL tear (all P < 0.01).

Conclusions: The ACL tear group is characterized by a greater PCTD, higher MIS index, and increased prevalence of FTD, which are high-risk factors for ACL tear group.

Advances in knowledge: This study demonstrates that increased prevalence of FTD and abnormal patellar position are significantly associated with a higher risk of ACL injury. By identifying these risk factors, our findings provide a foundation for screening high-risk populations and designing targeted prevention strategies, potentially reducing the incidence of ACL tears in susceptible individuals.