The American Academy of Orthopaedic Surgeons, or AAOS, points out that the types of artificial hips used in joint replacement are the same regardless of the surgical approach. The choice to use a cemented, cementless or hybrid hip replacement is based on an evaluation of a patient, whereas the surgical approach is a matter of surgeon preference. The choice of implant design depends on a combination of patient evaluation, surgeon preference and hospital standards.
Implant Design
An artificial implant or prosthesis replaces the ball and socket of the hip joint. The femoral component consists of a ball and stem that inserts into the thighbone. The cup-shaped acetabular component fits into the socket in the pelvis. According to the AAOS, the ball and stem may be separate components in some designs, which allows for more adjustability. The implants are constructed of metal alloys, polyethylene plastic or ceramic materials.
Anterior Approach
The anterior surgical approach to the hip is considered by proponents to be less invasive. Dr. Stefan Kreuzer, in an article published in the June 2006 issue of the "US Musculoskeletal Review," documents the advantages of the anterior approach: fewer muscle groups affected, preservation of stabilizing muscle groups, shorter recovery times and fewer post-operative precautions.
Cemented Hip
In the cemented hip option, surgical cement binds the femoral and acetabular implants to healthy bone. According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, cemented hips are generally used in older patients who are less active or in younger patients who have conditions such as osteoporosis. The AAOS notes that patients with a cemented hip can put full weight on the operated leg and walk without support soon after surgery. In some cases, the implant in this type of replacement may loosen, necessitating revision surgery.
Cementless Hip
The femoral and acetabular components of the cementless hip are textured or coated with a porous substance that allows new bone to grow into the prosthesis. Once bone growth has occurred, the implants are solidly fixed into the thighbone and socket. In some cases, screws or pegs may further secure the acetabular component. Because new bone takes time to grow, the recovery period for the cementless hip is longer than for the cemented type. The AAOS notes that candidates for the cementless implant are generally younger, more physically active and have healthier bones.
Hybrid Hip
The hybrid hip consists of a cemented component -- usually the ball and stem -- and a cementless component -- usually the socket. As the AAOS points out, the hybrid hip has the advantage of utilizing the best properties of both the cemented and cementless options.
