The hip joint is responsible for attaching the leg to the torso. In the hip joint, the head of the thigh bone (the femur) moves in a socket (the acetabulum). Pain in the hip joint can be caused by any type of trauma, but is most often associated with degenerative joint disease or osteoarthritis. In fact, osteoarthritis is the most common cause of hip pain in patients over the age of 50.
Osteoarthritis is caused by the breakdown and wearing away of the cartilage of the joints. The hip joint’s femoral head and the acetabulum are lined with cartilage that, when in perfect health, allows the bones to move with less friction. Cartilage serves as a cushion between the bones. When degeneration of the cartilage occurs, friction and inflammation can cause hip pain.