Correlation between Femoral Intercondylar Notch Width and Anterior Cruciate and Posterior Cruciate Ligament Widths on MRI of Knee Joint.

Background Anatomic variations have been implicated as one of the intrinsic causes of injuries to the cruciate ligaments which can induce a functional deficiency to the knee. Narrow cruciate ligament widths as well as narrow femoral intercondylar notch widths can increase the risk of these ligaments rupturing. Objective To correlate the width of the femoral intercondylar notch (ICN) with anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) widths on MRI of the knee joint. Method A total of 46 patients who met the inclusion criteria were evaluated. Intercondylar notch was identified on coronal T1W images while anterior cruciate ligament and posterior cruciate ligament were identified on proton density coronal images. All the widths were measured in the same plane at a mid-coronal level where anterior cruciate ligament and posterior cruciate ligament cross each other. Result Our result showed a significant correlation between the widths of intercondylar notch and anterior cruciate ligament (r = 0.68, p < 0.001) and between intercondylar notch width (INW) and posterior cruciate ligament width (r = 0.65, p < 0.001). Overall, the mean intercondylar notch width measured was 17.5 ±2.5 mm (range 11.8 to 21.8 mm), the mean anterior cruciate ligament width was 5.9 ±1.3 mm (range 3.3 to 8.6 mm), and the mean posterior cruciate ligament width was 8.9 ±1.5 mm (range 5.9 to 11.8 mm). A statistically significant difference was observed between males and females for mean widths of intercondylar notch (p < 0.001) and posterior cruciate ligament (p=0.01). However, no statistically significant difference was seen for anterior cruciate ligament width (p=0.07) between the two genders. Conclusion Measurement of the femoral intercondylar notch width can be used as an indicator of anterior cruciate ligament and posterior cruciate ligament widths which can further assist to identify the individuals who are more susceptible to cruciate ligament injuries.