Behaviour of medial meniscus extrusion in patients with knee osteoarthritis during stair ambulation.

Abstract

Evaluation of medial meniscus extrusion (MME) during motion can detect the behaviour of the MME including an increase in MME (ΔMME) and MME peak timing. These parameters reflect the pathology of knee osteoarthritis (KOA). Stair ambulation requires a greater knee flexion angle and produces higher mechanical stress on the meniscus; however, meniscus behaviour during stair ambulation remains unclear. To reveal meniscus behaviour during stair ambulation in patients with KOA. Twenty-five patients with medial KOA and 10 healthy controls were enrolled. The participants ascended and descended stairs without any support. ΔMME and MME peak timing as indicators of meniscal behaviour and knee flexion angle and knee adduction moment peaks as biomechanical parameters during stair ambulation were measured using ultrasonography and a three-dimensional motion analysis system, respectively. These parameters were compared between the KOA and control groups. No significant difference in biomechanical parameters was observed between two groups. The KOA group showed higher ΔMME and more delayed MME peak timing during stair descent than those in the control group, but not during stair ascent. The evaluation of MME during stair descent detected unique meniscus behaviour in patients with KOA.