The hip is a ball-and-socket joint. This type of joint allows a good range of movement in any direction.
The ball of the hip joint is known as the femoral head and is located at the top of the thigh bone (the femur). This rotates within a hollow, or socket, in the pelvis, called the acetabulum.
Hip replacement surgery is a procedure in which a doctor surgically removes a painful hip joint with arthritis and replaces it with an artificial joint often made from metal and plastic components. It usually is done when all other treatment options have failed to provide adequate pain relief. The procedure should relieve a painful hip joint, making walking easier.
This procedure is also sometimes used to treat injuries such as a broken or improperly growing hip, and for other conditions.