Femoroacetabular impingement (FAI) is a condition characterized by excessive friction in the hip joint from the presence of bony irregularities. These cause pain and decreased range of hip motion.
The femoral head and acetabulum rub against each other, causing damage and pain to the hip joint. The damage can occur to the articular cartilage (the smooth white surface of the ball or socket) or the labral tissue (the lining of the edge of the socket). The articular cartilage or labral tissue can fray or tear after repeated friction. Over time, more cartilage and labrum are lost until eventually the femur and acetabulum impact on one other. Bone-on-bone friction is commonly referred to as osteoarthritis.
Stress fractures of the hip are a break in the upper part of the thigh bone (femur) that fits into the socket of the hip joint. It can occur in any part of the hip, however, it mostly occurs just below the ball of the ball-and-socket hip joint called the femoral neck.
Stress fractures of the hip are more common in distance runners (high-mileage runners), ballet dancers or high impact athletes of any age.
Osteoarthritis, also called degenerative joint disease, is the most common form of arthritis. It occurs most often in the elderly. This disease affects the tissue covering the ends of bones in a joint called cartilage. In osteoarthritis, the cartilage becomes damaged and worn out, causing pain, swelling, stiffness and restricted movement in the affected joint. Although osteoarthritis may affect various joints including the hips, knees, hands, and spine, the hip joint is most commonly affected. Rarely, the disease may affect the shoulders, wrists, and feet.