Hip replacement surgery involves replacing either the ball or the socket component of the hip joint, or both. The ball component is the femoral head and the socket is the acetabulum. The goal of hip replacement is to improve the quality of life and decrease pain. A decision on what type of hip replacement to perform is based on patient age, the reason for the replacement, patient activity level, and orthopaedic surgeon preference.
Cementless Total Hip Replacement
A cementless total hip replacement involves removal of the femoral head and neck then placement of a metal stem with a ball into the femur or thigh bone, according to the American Academy of Orthopaedic Surgeons. A new metal socket with a plastic liner is also placed into the acetabulum or socket after it is ground down with surgical instruments to allow the socket to stick without the aid of cement. Some of the cementless components allow the patient's bone to grow into the components to tighten up the fit. Cementless designs can be used in any patient, but are more commonly used in younger patients.
Cemented Total Hip Replacement
Cemented total hip replacement involves removing the femoral head and neck and replacing this with a metal stem and ball and including a new hip socket component, according to the American Academy of Orthopaedic Surgeons. The metal stem and ball along with the hip socket component are anchored into the bone with the aid of a bone cement known as polymethylmathacrylate. Patients generally can weight bear earlier with this type of replacement. In the long-term, the cement can crack leading to a loosening of the replacement and need for a new total hip replacement surgery. Cemented total hip replacements provide significant benefit to patients regarding quality of life concerns.
Partial Replacement
If only either the ball or the socket component is diseased, a surgeon can choose to just replace the affected part of the joint. Usually the femoral or ball component of the joint is replaced in this procedure, according to the American Academy of Orthopaedic Surgeons. Many hip fractures are treated with a hemiarthroplasty procedure only replacing the femoral component of the joint and leaving the patient with the native acetabulum. Hemiarthroplasty is the term for only performing half of the total replacement. The most common type of a partial hip replacement is known as a bipolar replacement.
Hybrid Total Hip Replacement
The hybrid total hip replacement is placing one component without cement and the other component with cement. Most surgeons cement the femoral stem and press fit the acetabulum component.
Hip Resurfacing
According to Dr. David Marker of the Rubin Institute for Advanced Orthopaedics in Baltimore, in a 2010 article published in the "Journal of Orthopaedic Surgery Research," the hip resurfacing arthroplasty may be recommended for patients below age 65 who have good bone quality, highly actively lifestyles and no known metal allergies. Hip resurfacing involves replacing the socket and covering the femoral head with a cap that allows the patient to retain the bone of the femoral head and neck. This makes any further surgery theoretically easier due to more residual bone to anchor the future femoral stem.
References
- "AAOS Comprehensive Orthopaedic Review"; Dr Jay Lieberman (editor); 2008.
- American Academy of Orthopaedic Surgeons: Hip Impants
- "Journal of Orthopaedic Surgery Research"; Does Commitment to Rehabilitation Influence Clinical Outcome of Total Hip Resurfacing Arthroplasty; Dr. David R. Marker et al; 2010
