Many patients requesting artificial joint replacement have recently become increasingly concerned about the choice of material for the joint prosthesis and the selection of a cephalic socket match. There is a lot of expertise involved in this issue. For the sake of understanding and facilitating the selection of patients and friends, a brief introduction is in order. The artificial total hip joint generally consists of four components: the acetabular cup and liner, the femoral head and the femoral stem. The acetabular cup and femoral stem are fixed to the bone (biologically fixed or cemented, described in a separate article), the liner is fixed in the acetabular cup, the femoral head is fixed to the femoral stem, and the two move between them to form the joint. The choice of head-socket match includes the choice of friction interface and the choice of head-socket size. The materials used to make the artificial joint are currently cobalt-chromium-molybdenum alloy, titanium alloy, bioceramics, and polymer cross-linked polyethylene. Titanium alloy has a modulus of elasticity closer to bone, but it is not wear-resistant and can only be used to make acetabular cups and femoral stem prostheses, and is not suitable for making femoral heads. Cobalt-chromium-molybdenum alloy is strong and wear-resistant, and can be used to make femoral heads, acetabular cups and femoral stems. Bioceramics can be used to make femoral heads and acetabular liners, and high molecular cross-linked polyethylene can only be used to make acetabular liners. Highly cross-linked polyethylene liners to metal heads and highly cross-linked polyethylene liners to ceramic heads (so-called hemi-ceramics) reduce wear and can reduce osteolysis. Metal-to-metal and ceramic-to-ceramic have a lower coefficient of friction, are more resistant to wear, and have a lower incidence of osteolysis, thus improving the survival rate of the prosthesis. Metal-to-metal prostheses are still relatively controversial. Clinical selection of the friction interface The factors affecting the service life of total hip prostheses, in chronological order, are surgical technique, fixation strength, osteolysis associated with friction interface wear, fatigue failure of the prosthesis, and the process of bone contouring around the prosthesis. In addition to prosthesis-related factors, patient factors and surgical considerations are equally important in the clinical selection of friction subsets. The main clinical considerations in the selection of the friction side are patient factors, including the patient’s age, physical condition, activity level, life expectancy, and economic status. In Chinese patients older than 60 years of age and with low activity levels, metal-to-polyethylene is still the preferred choice. The conventional choice of metal-to-metal or ceramic-to-ceramic would significantly increase the economic burden on the individual and society and is neither necessary nor appropriate for national conditions. For younger patients, with high activity and long life expectancy, a more wear-resistant ceramic-to-ceramic or metal-to-metal prosthesis should be preferred in order to obtain better long-term results. Patients with metal allergy and renal impairment must also be excluded when selecting metal-to-metal friction partials. Selection of head socket size The diameters of the femoral head currently used are 22mm/28mm/32mm/36mm. 22mm femoral head is mainly used for certain patients with hip dysplasia who cannot be fitted with a standard acetabulum. 28mm femoral head is the most used, which is often referred to as the standard head. 32mm and above is called the large diameter femoral head, and the patient’s acetabulum must be of sufficient size to be selected for fitting. The larger the diameter of the femoral head the lower the dislocation rate of the artificial joint, and the greater the range of motion of the joint, which can better meet the requirements of young people. The large head prosthesis is stable and the range of motion after total hip replacement is close to that of a normal person. For young people who are more active, a large diameter ceramic-to-ceramic prosthesis or a ceramic-to-super high polymer high cross-linked polyethylene prosthesis can be used.