Who can have a hip resurfacing surgery?
Hip resurfacing surgery is a possible consideration for patients with severe hip arthritis. Hip resurfacing has been recommended to patients who are younger, and may face multiple surgeries over the course of their lifetime. No studies have shown that hip resurfacing is better for young patients, but there are theoretic advantages that have led some doctors to pursue this possibility.
Why did hip resurfacing fall out of favor in the 1970s?
Hip resurfacing was a popular procedure several decades ago. The implants used at that time were made of metal and plastic. Unfortunately, these implants had significant problems, and often failed in the first several years following surgery. These patients often required additional surgery, even within a short time following their initial hip resurfacing.
What has led to the recent increase in hip resurfacing surgeries?
In the 1990s, new hip resurfacing implant designs were introduced. The hip resurfacing implants are now made entirely of metal, with two separate pieces. One of the metal implants is a "cap" placed on the ball of the ball-and-socket hip joint, and the other side of the implant is a metal cup that forms the socket of the joint. These implants have not shown the high rate of early failure seen in the metal and plastic implants of the 1970s and 80s.
Some surgeons have advocated hip resurfacing implants because of several potential advantages. These advantages include:
- Maintenance of normal bone
Hip resurfacing surgery removes less bone than a standard hip replacement. In a standard hip replacement, the entire ball of the ball-and-socket hip joint is removed. In a hip resurfacing surgery, instead of removing the ball, a metal cap is placed around where the cartilage has worn off.
Furthermore, because the bone around the implant is supporting the metal cap, this bone tends to remain healthy and strong. The bone around a standard hip replacement can become thin and weak if the hip replacement implant supports the entire load. This problem is called "stress shielding," and is seen less commonly in hip resurfacing.
- Less risk of dislocation
Hip resurfacing implants better replicate the normal anatomy of the hip joint, and therefore have a lower risk of dislocation following surgery. Especially in younger, more active patients, dislocation can be a significant risk of hip replacement surgery.
- Easier revision
In the event that the hip resurfacing surgery does not last the entire life of the patient, the revision (repeat) replacement is not as difficult. Every time a revision procedure is performed, a larger surgery and larger implant must be used. By minimizing the bone removed, and using a smaller implant, the revision surgery following hip resurfacing surgery can be more like performing a standard hip replacement.
The ideal patient for a hip resurfacing procedure is a young (less than 60 years old) patient with strong bone around the hip joint. Young patients are of particular concern to joint replacement surgeons because of the chance they will need additional replacements (revision hip replacement) at some point later in life. The hip resurfacing procedure is thought to preserve more bone, and prevent possible complications associated with revision hip replacement surgery.
Who is not a good patient for a hip resurfacing surgery?
Patients with problems in the bone around the hip joint should not undergo a hip resurfacing surgery. These include patients who have bone loss as a result of their arthritis, patients with osteoporosis, and patients with cysts within the bone. Any of these conditions can weaken the bone around the hip joint, and lead to complications of hip resurfacing surgery.
Other factors may sway patients away from considering a hip resurfacing procedure. These factors include:
Patients over the age of 60 should carefully consider standard hip replacement surgery. While hip resurfacing provides some theoretic advantages, we know that most patients over the age of 60 will do extremely well with a standard hip replacement. Revision surgery (repeat hip replacement) becomes much less commonly necessary in patients over 60 years old, and therefore, standard hip replacement is usually favored.
Women have been shown to have a higher rate of complication from hip resurfacing surgery. The exact cause of this is not known, but it is thought to be due in part to the strength of the bone supporting the hip resurfacing implant. Women have been shown to have up to double the risk of fracture around the implant following hip resurfacing surgery.
Patients who are overweight have also experienced a higher rate of complication following hip resurfacing surgery. Some of this problem is thought to be due to increased force on the bone supporting the implant, as well as technical difficulty in the surgery on a larger patient.
- Inflammatory Arthritis & Osteonecrosis
Patients with inflammatory arthritis, such as rheumatoid arthritis, or osteonecrosis causing their hip problems, should consider a standard hip replacement. These patients often have bone abnormalities that could lead to problems supporting the hip resurfacing implant. Your doctor may order special tests to determine if there is adequate bone to support the hip resurfacing implant.