Disclosed therein is a big 
femoral head and 
femoral head surface replacement, which are used for hip 
osteoarthritis and vascular 
necrosis of 
femoral head. As a person get older and aged, the 
weight bearing hip joint is indispensably changed to 
osteoarthritis and sometimes showed 
avascular necrosis of the femoral head with unknown 
etiology. The deformed femoral head and hip joint should be replaced with the THA. Till now, the 
total hip replacement is performed in such a way that the necrosed femoral head and a healthy 
femoral neck are all removed and a 
femoral stem is inserted into the marrow cavity, and in this case, a small femoral head causes a reduction of a 
range of motion and 
dislocation of the hip joint occasionally, and 
osteolysis due to abrasion of plastic 
acetabular liner. In case of a conventional femoral 
head surface replacement (hereinafter, called “conventional FHSR”), a complication of 
femoral neck fracture and could not 
combined use with conventional THA. Recently, hard bearing 
system such as 
metal on 
metal THA or 
ceramic on 
ceramic THA without using plastic has been introduced to solve the problem of 
osteolysis due to abraded plastic particles generated when the THA is worn out as time goes. But there also have many problems as a limited 
range of motion, resected normal 
femoral neck and difficulties of rereplacement of the 
femoral stem. Because of the big femoral head or the FHSR can increase the 
range of motion and lower 
dislocation rate these devices are gradually widespread in young active person and Asian peoples. This invented design of the 
modularity gives the convenience to the surgeon and economically lower burden to patients to use of the FHSR and big femoral head 
system. The related accessory showed 
initial stability of the FHSR during operation and prevent from femoral neck fracture in follow-up periods.