Knee osteoarthritis (gonarthrosis) describes the degenerative wear of the joint cartilage in the knee with accompanying changes in bone, menisci, joint capsule and surrounding muscles. It is one of the most common forms of osteoarthritis of the musculoskeletal system.
Depending on the location, medial, lateral and retropatellar forms are distinguished; often a combination is present. Clinically there is load-dependent pain, start-up pain after rest, increasing restriction of movement and occasional joint effusions. Risk factors include age, leg axis malalignment, previous meniscus and cruciate ligament injuries, and excess weight.