The Difference in Medial Meniscal Extrusion between Non‐Weight‐Bearing and Weight‐Bearing Positions in People with and without Medial Compartment Knee Osteoarthritis

Background Medial meniscal extrusion (MME) has been correlated with medial meniscal injury and progression of medial knee osteoarthritis (OA). Objective To examine the difference in MME between non‐weight‐bearing (supine) and weight‐bearing (standing) positions in patients with and without medial knee OA. Determine the correlation between body mass index (BMI), Kellgren‐Lawrence (KL) grade, Knee Osteoarthritis Outcome Score (KOOS), and MME. Design Prospective. Setting Tertiary institution PM&R Department. Participants Forty five participants (29 female, 16 male), 24 with healthy knees and 21 with OA. Methods or Interventions A single physician sonographer measured supine and standing MME with ultrasound (US) on each participant. The physician was blinded to all measurements. BMI was recorded on all participants. KL grades and KOOS questionnaires were obtained for the OA group. Main Outcome Measures MME in supine and standing positions, change in MME from supine to standing, BMI, KL grade, and KOOS subscale scores. Results MME increased .52 mm from supine to standing (P