Objective: To evaluate how the 3D knee joint space distribution in knee OA patients changes under the influence of weight-bearing (upright) and flexion MRI scanning. Study design: Explorative cross-sectional study. Study population: 21 patients with symptomatic knee osteoarthritis (Kellgren-Lawrence grade 2 or 3) are included from the orthopaedics department of Medisch Spectrum Twente in Enschede. Main study parameters/endpoints: The primary study parameter is the change in medial joint space width between the different positions (weight-bearing/non-weight-bearing and flexion/extension).