Unicondylar Knee Arthroplasty

What is Unicondylar knee Arthroplasty?

When one compartment of the knee joint is arthritic then replacing this part with a metal and plastic joint is known as unicompartmental knee replacement or Unicondylar knee Arthroplasty. As compared to total knee replacement whole joint cartilage is not replaced. The benefit of this operation is that the patient can bend the knee fully and can squat. Hospitalization for this surgery is just two days.

The partial knee replacement surgical procedure has generated significant interest because it entails a smaller incision and faster recovery than traditional total joint replacement surgery. Partial knee replacement, also called unicompartmental knee replacement’ and ‘minimally invasive knee surgery,’ removes only the most damaged areas of cartilage, and replaces these surfaces.

Who is a good candidate for Unicondylar knee Arthroplasty?

The minimally invasive partial knee replacement is indicated in patients who have unicompartmental severe arthritis of the knee that had failed conservative treatments may consider this procedure. Conservative measures may include but are not limited to, medications, cortisone injections, strengthening exercises, and weight loss. If these treatments are not adequate, and you as a patient are not satisfied, then surgical procedures may be considered. Partial knee surgery may be possible if arthritis in the knee is confined to a limited area. If the arthritis is widespread, then partial knee replacement is not appropriate, and should not be considered.

In addition, partial knee surgery is recommended in patients who are:

• Older than 55 years
• Not obese
• Relatively sedentary
• Have intact ligaments (specifically the ACL)
• If these qualifications are not met, then minimally invasive partial knee surgery may not be as successful. Unfortunately, many patients are therefore ineligible for this minimally invasive procedure.

Unicondylar Knee Arthroplasty Procedure

Unicondylar knee arthroplasty may be performed under either general or spinal anesthesia. The surgery generally takes 1 to 2 hours to complete. The surgeon makes an incision at the front of the knee close to the affected area. This incision provides the surgeon with the opportunity to assess the structures of the knee, to ensure that the nearby ligaments are healthy and that the damage is confined to one specific area. If arthritis is present in multiple areas of the knee, total knee arthroplasty may have to be substituted for partial knee replacement.

Assuming that the damage to the knee joint is confined to one region, the unicondylar replacement will proceed. The surgeon will excise small pieces of cartilage and bone from the affected portions of the femur (thigh bone) and tibia (the larger bone of the lower leg). The segments of bone are replaced with metal prosthetics and fixed in place with cement. The metal implants at the ends of the bones are separated by a plastic insert that allows for smooth, fluid motion of the joint after surgery.

Recovery from a Unicondylar Arthroplasty

Recovery from a partial knee replacement is normally shorter and more comfortable than recovery from a total knee arthroplasty. Unicondylar knee replacement is a less invasive procedure, performed through a smaller incision. However, even a partial knee replacement typically requires a hospital stay of 1 to 3 days.

Most patients require the use of an assistive device such as crutches or a walker for the first week or two following the procedure to prevent putting too much stress on the knee as it heals. Physical therapy is important as it can help the knee to regain strength and flexibility. After a partial knee replacement, many patients fully recover within 6 weeks and are able to resume their usual activities, including low-impact sports.