Hip hemiarthroplasty is an orthopedic procedure for the treatment of certain femoral neck fractures where the femoral head is removed and replaced. The prefix hemi (meaning half) refers to the fact that the prosthetic femoral head articulates with the native acetabulum.
Hemiarthroplasty is indicated for the surgical treatment of subcapital neck fractures that are displaced and at high risk of femoral head avascular necrosis, (Garden III and IV fractures) if treated with DHS internal fixation . As the procedure is quicker and far less morbid than internal fixation, hemiarthroplasty is also routinely used in older, less active and co-morbid patients that would not be good surgical candidates for total arthroplasty. In younger or more active patients, outcomes are better with total hip arthroplasty .
The femoral stem is inserted similar to that of a total hip arthroplasty and can be cemented or non-cemented. When cemented, you may see a plastic medullary cavity plug as seen in case 1, to stop inferior migration of the cement. Many guideline organizations worldwide recommend cemented technique as standard .
The prosthesis may be a bipolar hemiarthroplasty which can be converted to a total hip arthroplasty in the future. The large prosthetic head can be removed and a smaller one attached to the femoral stem and an acetabular cup prosthesis is inserted. This is going out of fashion due to the added complication of osteolysis.