An artificial knee is a medical device which is designed to replace damaged components of the human knee. Artificial knees are used in patients with knees which are so severely damaged that they cannot be repaired or restored to a normal level of function. With an artificial knee and some rehabilitation, a patient can regain his or her former activity level, although people who have been highly physically active may experience some limitations after knee replacement surgery.
These medical devices are made from plastics and metals which will not react with the body. They are installed by orthopedic surgeons who will remove the damaged or diseased bone, and anchor the artificial knee in place. Some artificial knees glue in with surgical cement, while others have a special mesh fitting which allows the bone to grow into and around the implant to hold it in place. Depending on the severity of the damage to the knee, an artificial knee may be non-constrained, with the body's ligaments holding it in place, or constrained, in which case the medical device is hinged because the body lacks the strength to provide articulation to the joint.
Knee replacement surgery can be used to address athletic injuries, birth defects, the effects of oseteoporosis, and other medical issues which cause damage to the knee, such as traumatic car accidents. Before surgery, medical imaging studies will be used to get pictures of the inside of the knee, to determine which type of artificial knee would be most suitable, and the patient will also be evaluated to confirm that he or she is a good candidate for the surgery.
After an artificial knee is implanted, the patient must attend physical therapy sessions to learn how to use it, and to develop strong muscles and ligaments around the knee. Physical therapy is designed to get the patient active and to help the patient achieve a desired activity level. The physical therapist may also work with specific concerns, like the desire to resume running or engaging in other types of sports. When a patient cares well for the new knee, it can last for decades after surgery.
The term “artificial knee” is also sometimes used to describe the joint in a prosthetic leg. People who lose their legs above the knee will experience greater success with a prosthesis if the device includes a knee which will allow the patient to bend and flex. Prosthetic knees are challenging to make well, as there are some specific concerns which must be addressed, such as patient comfort, ease of use, long-term wear and tear, and cost.