DEAR DOCTOR K:
I’m scheduled to have hip replacement surgery. What complications can occur with a replacement joint?
I’m answering your question as both a doctor and a patient, since I had a hip replacement about a decade ago.
First, the basics. Your hip is a ball in a socket joint: The big bone in the top part of your leg has a top that’s shaped like a ball, and your pelvic bone has a cup into which the ball fits. Hip replacement surgery involves replacing the bony ball and socket with an artificial device made of metal or ceramic.
Before I talk about what can go wrong with hip replacement surgery, let me first say that these complications are unusual. Fortunately, none of these things happened to me, and the surgery relieved my chronic pain. My only regret, as is true with most of my patients who undergo hip replacement surgery, is that I waited too long to have it done.
So what can go wrong?
- Infection. Your implant can become infected. This usually happens when infection elsewhere in the body travels in the blood and lands on the tissue around the implant. If you feel new pain in the implanted hip, particularly if you also feel sick and have a fever, seek immediate treatment.
- Leg-length discrepancy. After surgery, muscle weakness or spasm and swelling around the hip may temporarily cause an abnormal tilt to your pelvis. This may make you feel as though your legs are unequal in length. It may be several months before you can tell if the discrepancy is temporary or real. If it’s real, it can be addressed with a lift in your shoe. If you also have pain, surgery can help.
- Dislocation. In the weeks after your hip replacement, take great care to keep from dislocating your implant before the surrounding tissues have healed enough to hold it in place. To reduce dislocation risk, do not bend over farther than your waist for about six weeks after your surgery. Also avoid turning your operated leg in or out. Even afterward, there is a chance of a painful dislocation.
- Loosening. A replacement joint can loosen because the cement never secured it properly or eventually wore out. This may also happen if the surrounding bone does not grow into the implant to create a tight attachment.
- Bone loss. As a joint implant suffers wear and tear, loose particles can be released into the joint. As your immune system attacks these particles, it can also attack surrounding bone and weaken it. This may loosen the bone’s connection to the implant.
Recently, problems have been identified with one type of metal-on-metal hip replacement device. Nevertheless, results continue to be excellent with the many other types of hip replacements.