Osteoarthritis is a chronic degenerative joint disorder characterized by loss of joint cartilage and degeneration of the underlying bone. Osteoarthritis is the commonest condition to affect joints in humans.
Which joints are affected by osteoarthritis?
Osteoarthritis can affect any joint but it occurs most often in knees, hips, small joint’s of the fingers and the bases of the thumb and big toe.
What happens in osteoarthritis?
In order to understand osteoarthritis affected joint, we need to understand a normal joint. The point at which two or bones are connected is called a joint. The bones in a joint are lined by a cartilage. Cartilage provides a smooth gliding surface for joint motion and acts as a cushion between the bones. A synovial membrane lines the cavity of joint from inside. The synovial membrane secretes synovial fluid which has a lubricating function. The joint is sealed by a dense fibrous connective tissue called joint capsule. The capsule along with overlying muscles and ligaments provide stability to the joint.
In osteoarthritis the cartilage breaks down causing pain, swelling and problems moving the joint. Because of the damaged cartilage the bone ends get exposed and tend to rub against each other. As osteoarthritis worsens over time bone ends may develop growths called spurs. Inflammatory process occurs that further damages the joint cartilage.