Abstract
PURPOSE: The aim of this study was to evaluate external tibial rotation using magnetic resonance imaging (MRI) in patients with injuries to the posterolateral corner (PLC) of the knee. METHODS: A retrospective analysis of 26 patients with PLC injury (study group) was performed and compared with a control group of 100 patients without knee injuries. Intra-articular tibial rotation was assessed in MRI measuring two angles: (1) between the surgical epicondylar axis (SEA) of the femur and the posterior tibial condyle line (PTC) (SEA-PTC); and (2) between the posterior femoral condyle (PFC) and the PTC (PFC-PTC). Results were aligned with the dial test (DT), representing the clinical assessment of PLC injuries. The statistical significance of differences in SEA-PTC and PFC-PTC was evaluated using a two-sided Welch's t test. RESULTS: The mean SEA-PTC was -6.3 ± 7.9° (study group) versus -6.1° ± 4.0° (control group), and the mean PFC-PTC was -5.2 ± 2.4° (study group) versus -5.4 ± 1.5° (control group). There were no statistical differences regarding the SEA-PTC or the PFC-PTC between both groups (p = 0.87 and p = 0.87, respectively). DT was positive in 80% of patients with PLC injury; thus, sensitivity was 80%. SEA-PTC and PFC-PTC were not statistically different between DT positive/negative patients (p = 0.89 and p = 0.1, respectively). There was a significant correlation between SEA-PTC and PFC-PTC (R = 0.88; p < 0.001). CONCLUSION: PLC injuries are not associated with increased external tibial rotation in the MRI, while the DT is a valuable method for the clinical assessment of PLC injuries. LEVEL OF EVIDENCE: Level III.