Medial meniscus extrusion increases with age and BMI and is depending on different loading conditions.

Abstract

Meniscus extrusion has always been described as an indirect sign of meniscus pathology and is associated with a loss of function of the affected meniscus. The current cut-off value of 3 mm displacement is indicated as abnormal and has been determined on magnetic resonance images (MRI) and ultrasound (US). However, it has to be considered that there is no description of the physiological meniscus extrusion in healthy knees depending on age or different weight-bearing conditions. It was hypothesized that in healthy knees there is a physiological age and BMI dependent meniscal extrusion, and meniscus extrusion depends on different loading conditions.