A unilateral knee replacement is a surgical procedure used to repair a segment of the knee. The surgery is considered non-invasive because only the damaged section of the knee is replaced. Outer sections of the knee, as well as the ligaments, are not disturbed. This can reduce the healing time considerably, and shortly after a unilateral knee replacement, the patient is typically encouraged to start walking again. Many patients who have moderate knee problems can receive this surgery, but there are a few exceptions.
People who suffer with joint injuries or a torn anterior cruciate ligament (ACL) cannot have a unilateral knee replacement because these conditions can typically cause too much damage to the entire knee area. Severe cases of arthritis also can cause too much deterioration to the outside portions of the knee. Patients who are obese are also not candidates for a unilateral knee replacement because the excess weight can hinder the healing process. There are also age requirements for this procedure. Elderly patients and younger children may not heal properly following this surgery.
A small incision is typically made during a partial, or unilateral, knee replacement procedure. The damaged joint is removed and replaced with either a plastic or metal implant. This implant acts very much like a human knee joint. If the surface of the knee cap is damaged, it may be also replaced. These implants are held in place by a cementing implant that is grouted into the natural knee, or by a press fit implant, which allows the natural bone to grow around it.
Following a unilateral knee replacement surgery, a cane or walker is usually required for a short period of time. When a patient can support his own weight without any discomfort, he can then learn to walk again. Since the implant can function better than a damaged knee, there is typically much less pain. Physical therapy can help to speed up the healing process.
With any surgical procedure, there are precautions and risks. A patient who has had a unilateral knee replacement surgery should avoid walking up stairs or squatting. Physical activities such as sports or excessive exercise should be kept to a minimum. Even if all precautions are taken, there can still be problems after this surgery.
Blood clots can occur if a patient does not exercise the knee properly. The plastic or metal implants can also come apart or break following surgery. If any bone fragments are released, they can enter the blood stream, causing further difficulties.