Medial opening-wedge high tibial osteotomy (MOW-HTO) is a well-established treatment option for patients with medial knee osteoarthritis. This thesis aimed to investigate the difference between healthy and arthritic knees in response to MOW-HTO alignment correction. Additionally, we aimed to investigate the effect of partial and complete superficial medial collateral ligament (sMCL) release across a range of clinically relevant alignment corrections. Cadaver knees were tested under axial loading while measuring tibiofemoral compartment pressure. Arthritic knees did not differ from healthy knees in response to alignment corrections. Compared to constitutional alignment, medial pressure decreased at post-operative mechanical axes crossing the tibial plateau at 50–55% of its width, while sMCL release did not impact medial pressure. This work shows that arthritic status was not a significant factor in MOW-HTO biomechanics and that significant unloading occurs after correcting the mechanical axis to 50– 55% of the tibial plateau width, irrespective of sMCL release.