Which condition is primarily characterized by degeneration of the joint cartilage?

Osteoarthritis is primarily characterized by the degeneration of joint cartilage. In this condition, the protective cartilage that cushions the ends of the bones wears down over time, leading to pain, stiffness, and reduced mobility in the affected joints. This degeneration can occur due to age, repetitive stress on the joints, or other contributing factors. As cartilage degrades, it can lead to changes in the underlying bone and bone spurs, which further exacerbate the symptoms.

In contrast, rheumatoid arthritis involves inflammation of the entire joint lining and is an autoimmune condition. Gout is typically associated with the accumulation of uric acid crystals in the joint, leading to sudden and severe attacks of pain and swelling. Joint capsulitis, or adhesive capsulitis, is characterized by stiffness and pain in the shoulder joint due to inflammation and thickening of the joint capsule, but it does not primarily involve cartilage degeneration.