Painful knees are a common problem—often the result of wear-and-tear from sports injuries or obesity, which leads to a degenerative form of arthritis called osteoarthritis. Pain relievers and other treatments can help. When knee damage is severe, a total knee replacement can relieve the pain and allow you to be more active again.
The knee is divided into three different sections:
- The inside or medial.
- The outside or lateral.
- The patellofemoral, behind the kneecap.
A partial knee replacement replaces the damaged surfaces in one or two of these places. A total knee replaces all three.
If your knee damage is limited to one of the bumps (condyles) on the end of your femur, you may benefit from a partial (unicompartmental) replacement that leaves the rest of the joint intact. This technology has been around for decades, but became more popular once surgeons were able to install the partial implant through a small incision (about three inches rather than eight) with minimal impact on muscles and ligaments—a surgery nicknamed the "mini-knee."
The potential advantages are clear: less blood loss, shorter hospitalization, and quicker recovery. However, a unicompartmental replacement lasts only about 10 years, compared with 15 to 20 years for a total knee replacement. They aren't well suited for people who are very bowlegged or knock-kneed. You may be offered this option only if damage is limited to one portion of the knee, if the damage results from a traumatic injury rather than arthritis, if your ligaments are intact, and if your knee still contains a fair amount of healthy cartilage. The ideal patient for this surgery remains an older, thinner person rather than a younger, more active one. It may be suggested to buy time before total knee replacement in someone young and active, however.
Obviously, not everybody is a candidate for a partial knee replacement. If you have arthritis on the outside or under your kneecap, then you wouldn't be a good candidate for a partial knee replacement.
A total knee replacement is a great thing for an arthritic knee. The pain's gone, you can walk a lot better and generally function a lot better; but it feels just a little bit mechanical because it is a little bit mechanical. But if you're a candidate for a partial knee replacement, this is a very good way to go.