To study the relationship between the presence of a Deep Lateral Femoral Notch Sign (DLFNS) in ACL injured patients and a higher Posterior Lateral Tibial Slope (LPTS), a reduced Meniscal Bone Angle (MBA), a higher LPTS/MBA ratio as well as a higher incidence of concomitant injuries in primary anterior cruciate ligament (ACL) tears. 

 

A retrospective case -control study was performed in patients submitted to primary ACL reconstruction with an available preoperative MRI scan. Patients with ACL tears and a femoral impactation with a depth ≥ 2mm were assorted to the DLFNS group, and patients with ACL tear and without a DLFNS to the control group. LPTS and MBA were measured in MRI. The presence of concomitant injuries (meniscal, posterior cruciate ligament, medial collateral ligament, lateral collateral ligament and bone injuries) was assessed in MRI. Quantitative data are presented in the median ± interquartile range (IQR). 

 

There were 206 patients included in the study, with 46 patients assorted to the DLFNS group and 160 patients to the control group. In the DLFNS group the median LPTS was 6.7° (IQR 4.0-8.2) versus 4.0° in the control group (IQR 2.2-6.5) (p=0.003). The LPTS/MBA ratio was significantly higher in the DLFNS group, with a median of 0.32 (IQR 0.19-0.44), in comparison to the control group, with a median of 0.19 (IQR 0.11-0.31) (p<0.001). The multivariable logistic regression analysis showed that the LPTS is an independent risk factor to having a DLFNS (OR=1.161; 95% CI 1.042-1.293, p=0,007). There was a higher incidence of concomitant lateral meniscal injuries in the DLFNS group (67% vs 48%, p=0.017). 

 

In patients with ACL tears, the presence of a DLFNS is associated with a steeper lateral posterior tibial slope, as well as a higher incidence of concomitant lateral meniscal injuries. 

 

Level III, case-control study 

 

Anterior Cruciate Ligament, Knee injuries; Femur Head; Tibial Meniscus Injuries23; Biomechanics