Partial knee replacement, also known as unicompartmental knee replacement, is a surgical procedure used to treat knee arthritis in patients where only one part of the knee joint is affected. The knee joint has three compartments: the medial compartment, the lateral compartment, and the patellofemoral compartment. In partial knee replacement, only the affected compartment is replaced with an artificial joint, leaving the rest of the knee joint intact.
 

Partial knee replacement is often recommended for patients with osteoarthritis or rheumatoid arthritis, who experience pain, stiffness, and swelling in the affected compartment of the knee joint. The procedure is less invasive than total knee replacement and has a quicker recovery time. However, it is only suitable for patients who have arthritis in one compartment of the knee joint and have not experienced significant damage to the ligaments or tendons in the knee.
 

The surgery is usually performed under general anesthesia or spinal anesthesia. During the procedure, a small incision is made over the affected compartment of the knee joint. The damaged cartilage and bone in the compartment are removed, and a metal and plastic implant is fitted to replace the removed parts. The implant is fixed to the bone using cement or special coatings that allow it to bond with the surrounding bone. After the implant is fitted, the incision is closed, and the patient is monitored closely in the recovery room.

Patients who undergo partial knee replacement typically have a shorter hospital stay and faster recovery time than those who undergo total knee replacement. Physical therapy is an important part of the recovery process, and patients are often advised to begin gentle exercises as soon as possible after the surgery to help restore strength and flexibility to the knee joint.