DEAR DOCTOR K: My hip has bad arthritis, and my doctor says I need either a hip replacement or something called “hip resurfacing.” Which one is best?
DEAR READER: I once had to ask myself that same question, when my right hip became so painful from arthritis that something needed to be done. Let me first explain what each type of surgery is, and then how to think about the choice between them.
The hip is a ball-and-socket joint. The ball — the top of the femur — fits into the socket, the cup-shaped area in the pelvis called the acetabulum. In a total hip replacement, the surgeon removes the damaged surface of the socket, and also removes the femoral head and the neck of the femur. Then the surgeon replaces the surface of the socket and the top of the femur bone with artificial components.
In a hip resurfacing, the surgeon replaces the socket — just as in a hip replacement. However, the surgeon keeps the femur in place, reshapes the ball on top of the femur and places an artificial cap (a new “surface”) on top of the ball. So both the ball and the socket have a new surface, but less surgery is done. Less bone is removed, and less soft tissue around the bone is injured. (I’ve put an illustration, below.)
The neck and head of the femur are preserved. The femoral ball component fits over the femoral head.
That’s the attraction of hip resurfacing: It’s simpler and faster than hip replacement. The recovery time is the same: three days in the hospital, followed by four to six weeks of physical therapy. Insurance pays for both procedures.
So far, so good. Based on what I’ve said so far, I might have chosen hip resurfacing over hip replacement. But not everyone who needs hip surgery can have hip resurfacing.
“The anatomy of the hip allows you to do a total hip replacement on anyone who needs it,” says my Harvard Medical School colleague Dr. Donald Reilly. “But not everyone has the right anatomy for hip resurfacing.” That includes small women with poor bone quality and people with certain femoral head anatomies that make femur fractures more likely. That was not a problem in my case: I could have had hip resurfacing.
The most important question is: How good are the results of hip replacement versus hip resurfacing? A recent study published in the British Medical Journal found that the results in the first few years are similar.
However, hip resurfacing is new enough that we don’t yet know how long-lasting the positive effects are. Traditional total hip replacement surgery has been practiced for nearly 50 years; we know a lot about the long-term results. The artificial parts of the new hip tend to last between 15 and 20 years.
Finally, there’s an increased risk of a particular fracture in hip resurfacing patients. If that fracture occurs, then you need a second operation — a hip replacement.
I decided that since I probably had at least 20 more years to live, I would have hip replacement: It was likely to last as long as I did.