Which of the following describes the degeneration process in osteoarthritis?

The degeneration process in osteoarthritis is primarily characterized by cartilage breakdown. Osteoarthritis occurs when the cartilage that cushions the ends of bones in the joints deteriorates over time. This breakdown leads to changes in the joint, including bony growths, changes in the amount and composition of synovial fluid, and a general weakening of the underlying bone. The loss of cartilage results in joint pain, swelling, and decreased mobility, which are hallmark symptoms of the condition. Understanding this central role of cartilage helps clarify why effective treatments often focus on protecting and maintaining cartilage health. Other options mentioned, such as inflammation of ligaments, fracture of bones, or muscle stiffness, may be associated with other musculoskeletal disorders or conditions but do not directly represent the degeneration process specifically linked to osteoarthritis.