Surface replacement of the hip is considered mainly for the young active patients, were convential total hip replacement will not be satisfactory.The advantages of using 3rd generation metal on metal articulation and the abandon of polyethelene gave metal on metal surface replacement a new prospective. The advantages of surface replacement are:1-preservation of the proximal bone stock.2-Preservation of normal hip biomechanics3-No violation to the medulla.4-No stress shielding to the proximal femur.5-Less dislocation.6-Better range of motion.7-Less volume of implants.Certain contraindication for surface replacement should be considered:Old age with osteoporosis. Collapse the femoral head