Partial (unicompartmental) knee replacement

A unicompartmental knee replacement is sometimes used instead of a total knee replacement when only one side of the knee has been damaged by osteoarthritis. Unicompartmental knee replacements involve smaller incisions, less bleeding, quicker recovery, and less bone loss than a total knee replacement.

The prosthesis does not interfere with existing ligaments, tendons, or nerves. You retain normal balance and the natural stability of the healthy half of your knee joint and your own tendons and ligaments. Your kneecap is left in place, enabling you to regain much of the strength in your quadriceps.

The minimally invasive partial knee replacement is indicated in patients who have severe arthritis of the knee that have failed conservative treatments may consider this procedure. Conservative measures may include, but are not limited to, medications (such as Advil, Naprosyn, Celebrex, and Vioxx), 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.

The partial knee surgery may be possible if the arthritis in the knee is confined to a limited area. If the arthritis is widespread, then the partial knee replacement is NOT appropriate, and should not be considered. In addition, the 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 the minimally invasive partial knee surgery may not be as successful. Unfortunately, many patients are therefore ineligible for this minimally invasive procedure.

Most patients who seek surgical management have arthritis that is too advanced for the minimally invasive partial knee replacement procedure. Because surgical treatment is considered a 'last-resort' by most patients, by the time surgery is necessary, their arthritis is too advanced to consider this minimally invasive procedure. If partial knee replacement is done in a patient who is a poor candidate, failure rates can be high, and conversion to a traditional total knee surgery may be more difficult.