The hip joint consists of a rounded part – the femoral head – and a concave socket – the pelvis acetabulum. The femoral head rotates freely within the acetabulum. In order to prevent friction, the area is covered by a smooth, shiny tissue -the cartilage- and by a small quantity of synovial fluid, acting as lubricant for the movements of the joint.

Hip osteoarthritis is a chronic degenerative disease, developing as a result of damage to the cartilage, which covers the surfaces of the joint. This results in stiffness and limping, with progressively increasing pain felt at the point where the leg joins the trunk, or in the front part of the leg, sometimes being reflected on the knee. All these symptoms oblige the patient to diminished activity.

In the early stages the condition is treated with medications. When this is no longer enough, a surgical intervention, total hip arthroplasty, becomes necessary. A successful operation allows the patient to resume a normal way of life.

The arthroplasty consists in replacement of the damaged bone and cartilage of the joint by an artificial joint, consisting of a femoral stem with a rounded head and an acetabulum cup. The operation can be performed using various techniques, which differ mainly in the surgical approach, that is the placement, direction and length of the incision that the surgeon uses to get to the joint.