Ankle Ligament Tears, Sprains and Instability of the Ankle Joint
When the ligaments that hold the bones of the ankle joint together are partially torn or stretched, as in the case of a bad sprain or repeated minor sprains, they can become painful, loose, and weak. This changes how you walk, putting painful stress on other joints of the foot, as well as making it more likely that you will sprain the ankle again. This leads to a cycle of chronic pain and instability.
Osteoarthritis of the Ankle
Osteoarthritis of the ankle usually occurs in ankles that have experienced trauma, infection, or injury. A smooth, slippery, fibrous connective tissue, called articular cartilage, acts as a protective cushion between bones. Arthritis develops as the cartilage begins to deteriorate or is lost. As the articular cartilage is lost, the joint space between the bones narrows. This is an early symptom of osteoarthritis of the ankle and is easily seen on X-rays.
As the disease progresses, the cartilage thins, becoming grooved and fragmented. The surrounding bones react by becoming thicker. They start to grow outward and form spurs. The synovium (a membrane that produces a thick fluid that helps nourish the cartilage and keep it slippery) becomes inflamed and thickened. It may produce extra fluid, which causes additional swelling.