What is a total hip replacement?

A total hip replacement is a surgical procedure whereby the diseased cartilage and bone of the hip joint is surgically replaced with artificial materials.

• The normal hip joint is a ball and socket joint. The socket is a “cup-shaped” component of the pelvis called the acetabulum. The ball is the head of the thighbone (femur).

• Total hip joint replacement involves surgical removal of the diseased ball and socket and replacing them with a metal (or ceramic) ball and stem inserted into the femur bone and an artificial plastic (or ceramic) cup socket.

• The metallic artificial ball and stem are referred to as the “femoral prosthesis” and the plastic cup socket is the “acetabular prosthesis.” Upon inserting the prosthesis into the central core of the femur, it is fixed with a bony cement called methylmethacrylate.

• Alternatively, a “cementless” prosthesis is used that has microscopic pores which allow bony ingrowth from the normal femur into the prosthesis stem.

• This “cementless” hip is felt to have a longer duration and is considered especially for younger patients.

• Total hip replacements are performed most commonly because of progressively worsening of severe arthritis in the hip joint such as degenerative arthritis (osteoarthritis) of the hip joint generally seen with aging, congenital abnormality of the hip joint, or prior trauma to the hip joint, bony fractures of the hip joint, rheumatoid arthritis, and death (aseptic necrosis, or avascular necrosis) of the hip bone.

• Hip bone necrosis can be caused by fracture of the hip, drugs (such as prednisone and prednisolone), alcoholism, and systemic diseases (such as systemic lupus erythematosus).

• The progressively intense chronic pain together with impairment of daily function including walking, climbing stairs, and even arising from a sitting position, eventually become reasons to consider a THP