Osteoarthritis of the Hip
Osteoarthritis of the hip usually occurs in hips 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 hip 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 that causes additional swelling.
Over a period of years, the joint slowly changes. In severe cases, when the articular cartilage is gone, the thickened bone ends rub against each other and wear away. This results in a deformity of the joint. Normal activity becomes painful and difficult.
Osteonecrosis of the Hip
Also called avascular necrosis, this is a disabling condition that can lead to the hip joint collapsing. It is estimated that doctors see about 10,000-20,000 new cases of osteonecrosis each year.
Osteonecrosis of the hip is caused by the blood vessels gradually cutting off nourishment to the top of the thighbone (head of the femur) where it fits in the hip socket. Without blood, the head of your femur dies and collapses. This can make it painful to move your hip, and you may develop arthritis and a limp.
Your doctor may flex and rotate your hips to check for pain. Your hips may be X-rayed and possibly scanned by MRI (magnetic resonance imaging) to see if bone marrow is dying or dead, and how much the head of your femur may have collapsed.
Chronic Hip Bursitis
This is a condition in which fluid-filled sacs near a joint – called bursae – become inflamed, causing pain and sometimes swelling. Under usual conditions, the bursae are flat and contain very little fluid. When they are injured, they become inflamed and swell with fluid, causing pain and pressure on the surrounding tissue.