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” bone of the pelvis called the acetabulum. The ball is the head of the thigh bone (femur).
Total hip joint replacement involves surgical removal of the diseased ball and socket, and replacing them with a metal ball and stem inserted into the femur bone and an artificial plastic or metal cup socket. The metallic artificial ball and stem are referred to as the “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 which has microscopic pores that allow bony in growth 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.
Who is a Candidate for Total Hip Replacement?
Total hip replacements are performed most commonly because of progressively severe arthritis in the hip joint. The most common type of arthritis leading to total hip replacement is degenerative arthritis (osteoarthritis) of the hip joint. This type of arthritis is generally seen with aging, congenital abnormality of the hip joint, or prior trauma to the hip joint. Other conditions leading to total hip replacement include bony fractures of the hip joint, and death (necrosis) of the hip bone. Hip bone necrosis can be caused by fracture of the hip, drugs (such as alcohol or corticosteroids), diseases (such assystemic lupus erythematosus), and conditions (such as kidney transplantation).
The progressively intense, chronic pain — together with impairment of daily function including walking, climbing stairs and even rising from a sitting position — eventually become reasons to consider a total hip replacement. Because replaced hip joints can fail with time, whether and when to perform total hip replacement are not easy decisions, especially in younger patients. Replacement is generally considered after pain becomes so severe that it impedes normal function despite use of anti-inflammatory medications. A total hip joint replacement is an elective procedure, which means that it is an option selected among other alternatives. It is a decision which is made with an understanding of the potential risks and benefits. A thorough understanding of both the procedure and anticipated outcome is an important part of the decision-making process.
What are the Risks?
The risks of total hip replacement include blood clots in the lower extremities that can travel to the lungs (pulmonary embolism). Severe cases of pulmonary embolism are rare, but can cause respiratory failure and shock. Other problems include difficulty with urination, local skin or joint infection, fracture of the bone during and after surgery, scarring and limitation of motion of the hip, and loosening of the prosthesis which eventually leads to prosthesis failure. Because total hip joint replacement requires anesthesia, the usual risks of anesthesia apply and include heart arrhythmias, liver toxicity, and pneumonia.