Pathogenesis (disease development)
Age-related wear and tear is not the cause of osteoarthritis, but at the beginning of the joint destruction is usually acute damage to the articular cartilage due to trauma or infection. The following pathomechanisms can be observed in osteoarthritis:
- Osteoarthritis due to excessive load on the joint.
- Osteoarthritis due to inferior bone or cartilage.
Primary osteoarthritis occurs as a result of direct or indirect overloading of the joints. Direct overloading occurs during heavy work, sports* or due to obesity. Indirect overloads include a reduction in cartilage regeneration due to aging or metabolic disorders. * Sport is only healthy, however, as long as joints are not damaged in the process or there are no pre-existing conditions. Secondary osteoarthritis can occur as a result of:
- Congenital / malformation
- Malposition
- Endocrinological disorders/diseases
- Metabolic disorders/diseases
- Inflammatory joint diseases
- Chronic inflammatory and non-inflammatory arthropathy (joint disease).
- Rheumatic joint disease
- Post-traumatic (after joint trauma/joint injury; dislocation – dislocation/dislocation).
- Operations
Osteoarthritis and inflammation (inflammation).
Low-grade inflammation (inflammation) seems to play a greater role in osteoarthritis (English osteoarthritis) than radiological changes in terms of osteoarthritis (signs of degeneration). This was shown by the determination of hs-CRP serum levels (high sensitivity CRP; inflammation parameter), which were slightly but statistically significantly increased compared to the control group.Clinically, about 50% of osteoarthritis patients show signs of synovial inflammation. The signs of synovitis (inflammation of the synovial membrane) are detectable even with minor symptoms and only limited structural changes. A typical immune cell infiltration with monocytes/macrophages and T lymphocytes (CD4 T cells) can be detected. Furthermore, cytokines (tumor necrosis factor alpha; IFN-γ/interferon-gamma), growth factors and neuropeptides appear during this process. The mediators stimulate proinflammatory (“proinflammatory”) cytokines, among others. The acromioclavicular joint (acromioclavicular joint) is subjected to severe mechanical stresses, so osteoarthritis of this joint is a symptom of aging in the majority of cases. The discus articularis is the articular disc that lies between the clavicle (collarbone) and scapula (shoulder blade). Degenerative changes in this interarticular disc can be seen as early as the 2nd decade of life. In young people, osteoarthritis of the acromioclavicular joint usually occurs after trauma (injury). Instability of the capsule-ligament apparatus also favors its development. There is often a combination with arthroses of large body joints (polyarthrosis).
Etiology (causes)
Biographic causes
- Genetic burden from parents, grandparents: e.g., vitamin D receptor (VDR) gene polymorphisms.
- There were significant associations between VDR apal polymorphisms and osteoarthritis in the Asian population, but not in the overall population
- There was also a statistically significant association between FokI polymorphisms and osteoarthritis; however, this result was derived from only two studies
- Age – age-related cartilage degeneration due to decreased metabolic activity.
- Occupations – occupations with long-lasting heavy physical loads (eg construction workers).
Behavioral causes
- Physical activity
- Overloading of the joints, e.g. due to competitive and high-performance sports in the power sports sector (e.g. bodybuilders) or long-lasting heavy physical loads at work
- Lack of physical activity – since the cartilage gets its micronutrients from the synovial fluid, it is dependent on the joint being moved
Disease-related causes
- Inflammatory joint diseases
- Rheumatic joint diseases
- Post-traumatic (after joint trauma/joint injury; dislocation – dislocation/dislocation; ligament injury; after a fracture (broken bone) of the clavicle).
