This article offers an in-depth look into osteoarthritis, highlighting its causes, affected joint components, and progression factors. It emphasizes the multifaceted nature of the disease and the importance of understanding joint changes for better treatments. The content is ideal for those seeking comprehensive knowledge about OA’s impact on joint health and potential interventions.

Osteoarthritis (OA) stands as the most common type of arthritis globally. It is a progressive joint disorder characterized by the degradation of cartilage and subchondral bone over time. Approximately 15% of the world’s population suffers from OA, predominantly affecting the hips and knees. The lifetime likelihood of developing this condition ranges from 40% to 47%, with athletes and those with excess weight being more vulnerable. Any joint can be affected, but knees and hands are frequent sites. Its origin is multifactorial, influenced by genetic, metabolic, biomechanical, and biochemical factors.

The primary joints involved include the cartilage, subchondral bone, and synovial lining. Damage to cartilage results from an imbalance between breakdown and repair processes, leading to thinning, softening, and cracks that expose the bone beneath. Changes in subchondral bone, such as cyst formations and osteophyte growth, compromise joint stability. The synovial membrane often becomes inflamed and thickened, producing pain-related substances. Degeneration of menisci further complicates OA, making it a multifaceted joint disease.

The sequence of cartilage versus bone changes remains uncertain, with factors like injury, inflammation, and enzymatic activity driving disease progression. Understanding these processes is vital for creating effective, targeted therapies for OA.