Partial Joint Replacement
(Joint Resurfacing; Unicompartmental Knee Arthroplasty)
by Cynthia M. Johnson, MA
Partial joint replacement is the use of an implant to replace an area of diseased or injured joint tissue. It may be done on the hip, shoulder, or knee joints.
Reasons for Procedure
Damaged joint tissue can cause pain and limit movement. Osteoarthritis is a common cause. It is the gradual wear and tear of joints over time. Less often, the damage is due to trauma.
This procedure is done to ease pain and improve function when other treatment methods have failed.
Problems are rare, but all procedures have some risk. The doctor will go over some problems that could happen, such as:
Things that may raise the risk of problems are:
What to Expect
Prior to Procedure
The surgical team may meet with you to talk about:
The doctor may give:
Description of the Procedure
An incision will be made along the joint. Muscles, tendons, and ligaments will be moved aside. The joint will be moved to access damaged area. The entire joint will be examined. The partial replacement may not be done if damage is widespread.
Damaged cartilage will be removed from the area and smoothed down. Any excess build-up of bone will also be removed. A metal cap will be placed over the newly cleaned surface. It is often held in with cement. A metal cup or plastic surface may be placed on the opposite joint surface. A plastic disc may be placed between the two new surfaces to help it glide smoothly. The muscles and tendons will then be moved back into place. The incision will be closed. A bandage will be placed over the area.
How Long Will It Take?
1 to 3 hours
Will It Hurt?
Pain and swelling are common in the first few days. Medicine and home care can help.
Average Hospital Stay
Some people go home the same day. The usual length of stay is 1 to 4 days. If you have problems, you may need to stay longer.
At the Hospital
Right after the procedure, the staff will:
During your stay, the hospital staff will take steps to lower your risk of infection, such as:
There are also steps you can take to lower your risk of infection, such as:
It will take 6 weeks to fully heal. Physical activity will be limited during this time. You may need to ask for help with daily activities and delay your return to work.
Call Your Doctor
Call your doctor if you are not getting better or you have:
If you think you have an emergency, call for medical help right away.
American College of Surgeons
Ortho Info—American Academy of Orthopaedic Surgeons
Canadian Association of General Surgeons
Canadian Orthopaedic Foundation
Osteoarthritis of the knee. EBSCO DynaMed Plus website. Available at: https://www.dynamed.com/condition/osteoarthritis-oa-of-the-knee. Accessed August 2, 2021.
Unicompartmental knee replacement. Ortho Info—American Academy of Orthopaedic Surgeons website. Available at: https://orthoinfo.aaos.org/en/treatment/unicompartmental-knee-replacement. Accessed August 2, 2021.
Last reviewed July 2021 by EBSCO Medical Review Board Warren A. Bodine, DO, CAQSM