Correlation of notch width index in knees with mucoid degeneration of anterior cruciate ligament to normal knees

Abstract

Background: Notch width index (NWI) is a most widely used two dimensional measurement of Intercondylar notch volume of the knee. ACL with mucoid degeneration if often underdiagnosed or overlooked cause of nonspecific knee pain and mild restriction of knee movements. ACL in this condition appears bulky and characteristically shows mucinous material along its fibers. We aim to find any correlation of Notch width index in knees with mucoid degeneration of ACL to knees of age matched controls. Methods: In this study, 32 patients diagnosed with Mucoid degeneration of ACL based on Magnetic Resonance studies were included. Notch width Index i, e width of the intercondylar notch divided by intercondylar width at 2/3 notch depth was measured on a coronal section on MRI. This data was compared with age matched controls using Pearson’s correlation Co efficient. Results: 22 patients in study group were females and 10 were males with age ranging from 25-73 years (Median age 45.5 years) The NWI in Mucoid degeneration of ACL when compared to normal knees showed a significant decrease (NWI -0.222±0.03 Mean in Mucoid ACL group; NWI- 0.311±0.03 in controls) in Intercondylar notch width viz Notch stenosis. Female patients compared to male had decreased NWI with 0.222 Mean. Conclusions: Mucoid degeneration of ACL leading to bulky ACL causing stenosis of the notch is evident in this study. However larger sampling size and volumetric analysis by other methods are needed to better manage this poorly understood condition.