by EBSCO Medical Review Board
(Joint Resurfacing; Unicompartmental Knee Arthroplasty)


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.

Osteoarthritis of the Knee
Knee arthitis
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Possible Complications

Problems are rare, but all procedures have some risk. The doctor will go over some problems that could happen, such as:

  • Excess bleeding
  • Problems from anesthesia, such as wheezing or sore throat
  • Infection
  • Blood clots
  • Damage to nerves or blood vessels
  • Joint stiffness or instability
  • Dislocation

Things that may raise the risk of problems are:

  • Smoking
  • Drinking alcohol
  • Chronic diseases, such as diabetes or obesity

What to Expect

Prior to Procedure

The surgical team may meet with you to talk about:

  • Anesthesia options
  • Any allergies you may have
  • Current medicines, herbs, and supplements that you take and whether you need to stop taking them before surgery
  • Fasting before surgery, such as avoiding food or drink after midnight the night before
  • Arranging for a ride to and from surgery
  • The need to switch to a full replacement if widespread damage is found during surgery


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.

Post-procedure Care

At the Hospital

Right after the procedure, the staff will:

  • Give you pain medicine or medicine to prevent blood clots
  • Encourage you to walk using a walker

During your stay, the hospital staff will take steps to lower your risk of infection, such as:

  • Washing their hands
  • Wearing gloves or masks
  • Keeping your incisions covered

There are also steps you can take to lower your risk of infection, such as:

  • Washing your hands often and reminding visitors and staff to do the same
  • Reminding staff to wear gloves or masks
  • Not letting others touch your incisions
At Home

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:

  • Signs of infection, such as fever and chills
  • Redness, swelling, excess bleeding, or discharge from the incision
  • Pain that you cannot control with medicine
  • Worsening joint stiffness, pain, or instability
  • Numbness, tingling, or loss of feeling

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: Accessed August 2, 2021.

Unicompartmental knee replacement. Ortho Info—American Academy of Orthopaedic Surgeons website. Available at: Accessed August 2, 2021.

Revision Information