When your knee is badly damaged by disease or injury, an artificial knee replacement may be considered. Osteoarthritis is the most common problem that leads to knee replacement surgery. This is a "wear and tear" joint disease that affects mostly middle-aged and older adults. Osteoarthritis leads to the breakdown of joint cartilage, and then bone, in your knees. Other forms of arthritis, such as rheumatoid and traumatic, can also lead to degeneration of your knee joint. Fractures, torn cartilage, and/or torn ligaments also can lead to irreversible damage to your knee joint over time. The decision to replace the painful knee with an artificial one is a joint decision between you and your healthcare provider. Other treatments may be used first. These include lubricating injections, steroid injections, physical therapy, assistive walking devices and anti-inflammatory medicines that help with pain and swelling.
During knee replacement surgery, your joint surfaces are replaced by prostheses where plastic, ceramic, and or metal parts are used to replace your joint surfaces. The most common type of knee prostheses used in replacement surgery is cemented prosthesis which, is attached to the bone with a type of epoxy. Uncemented prosthesis is not commonly used however, it is an alternative option and is attached to the bone with a fine mesh of holes on the surface, in order for the bone to grow into the mesh and attach naturally to the prosthesis. Sometimes, a combination of the 2 types is used to replace a knee.
The prosthesis (artificial knee) is made up of the following 3 components:
- Tibial component (to replace the top of the tibia, or shin bone)
- Femoral component (to replace the two femoral [thighbone] condyles and the patella groove)
- Patellar component (to replace the bottom surface of the kneecap that rubs against the thighbone)
Although each procedure varies, generally, surgery to replace a knee usually lasts about 2 hours. After the damaged bone and cartilage of the knee is removed, the orthopedic surgeon will place the new artificial knee in its place. While undergoing surgery, the patient may be under general anesthesia or awake with spinal or epidural anesthesia.
Knee replacement procedures:
- Total knee replacement
- Bi-lateral knee replacement
- Partial knee replacement