A total hip arthroplasty, THA, most commonly occurs when the hip joint is compromised due to disease or trauma. The hip joint, focusing on the acetabulum and femoral head, is replaced by a prosthetic implant. This implant requires a acetabular cup, liner, femoral head, and femoral stem. These components can be made from a combination of metals, plastics, or ceramics to create a total prosthesis.

The hip joint is a ball-and-socket joint, meaning the joint is made up of a rounded surface of bone that moves within a depression of another bone. Therefore the femoral head moves in the depression of a acetabulum. The anatomy of the hip is composed of many ligaments that provide stability to the joint. This joint is one of the most weight bearing joints in the body and allows for movement in flexion, extension, and abduction. The extracapsular ligaments help prevent hyperextension and excessive abduction as well as holding the femoral head to the acetabulum. The ligament of the femoral head, located between the femoral head and acetabulum and keeps the femoral head from dislocating from the acetabulum. During surgery the ligament of the head of femur is completely removed for the implant. Removing this ligament removes a main ligament of stability within the joint.

Within the United States 450,000 total hip arthroplasty's are preformed each year. The typical cost range for this procedure is $31,000 - $45,000 and sometimes less depending on insurance. During the first few months after surgery the risk of dislocation is at its greatest because the tissues are still healing. There is a dislocation rate of primary hip replacements of 2% - 10%. Whenever a dislocation occurs a physician can preform a closed reduction where they can put the ball back into the socket without the need for more surgery. However, if the dislocation is severe there could be a need for a revisional surgery.