Gonarthrosis – colloquially called knee osteoarthritis – (synonyms: Osteoarthritis of the knee joint; Degenerative disease of the knee joint; Knee osteoarthritis (KOA); ICD-10-GM M17.-: Gonarthrosis [osteoarthritis of the knee joint]) is a degenerative, noninflammatory joint disease of the knee. It refers to wear and tear of the articular cartilage and other joint structures (bone, joint capsule, muscles near the joint).
Normally, the cartilage, together with the synovial fluid (synovial fluid), protects the joints and acts as a kind of “shock absorber”. This enables pain-free and unrestricted mobility of the joint. Due to arthrosis, this function can no longer be guaranteed.
Gonarthrosis is divided into the following forms:
- Primary gonarthrosis – bilateral (ICD-10 M17.0).
- Other primary gonarthrosis – unilateral (ICD-10 M17.1)
- Posttraumatic gonarthrosis – bilateral (ICD-10 M17.2)
- Other post-traumatic gonarthrosis – unilateral (ICD-10 M17.3)
- Other secondary gonarthrosis – bilateral (ICD-10 M17.4)
- Other secondary gonarthrosis – unilateral (ICD-10 M17.5)
The human knee consists of three bones that, together with a capsular and ligamentous apparatus, form the knee joint. Depending on which joint sections of the knee are affected, one speaks of:
- Retropatellar osteoarthritis – the patellar joint surface is mainly affected.
- Medial gonarthrosis – the inner part of the knee joint is mainly affected
- Lateral gonarthrosis – the outer part of the knee joint is mainly affected
- Pangonarthrosis – all three previously mentioned joint sections of the knee are affected by degenerative changes
Furthermore, there is osteoarthritis of the femoral condyle (femoral rolls) and osteoarthritis of the tibial plateau (tibial plateau).
The knee joints, along with the hip joints, are most frequently affected by degenerative changes in older age (gonarthrosis: 61%, right more frequently than left; coxarthrosis (osteoarthritis of the hip joint): 38%). Both knee and hip joints are particularly stressed by body weight.
Gender ratio: Women are more frequently affected than men.
Frequency peak: Patients are usually affected after the age of 50. The disease occurs predominantly in older age (> 60 years of age).In those over 60 years of age, radiologically detectable and 12.1% symptomatic gonarthrosis is present in 37.4% of cases (USA).
The prevalence (disease incidence) is approximately 10% in the group over 70 years of age with clinical symptoms. Radiographic signs of gonarthrosis are detectable in approximately 40% of those over 70 years of age.
Course and prognosis: The onset of gonarthrosis is usually insidious. The disease progresses slowly. It is not curable, but adequate treatments can significantly alleviate symptoms and prevent progression (progression). In the context of gonarthrosis, the quality of life can be severely limited. If left untreated, the affected person will ultimately be unable to move the knee without pain, and in the worst cases it may even stiffen.
