Partial Joint Replacement

(Joint Resurfacing; Unicompartmental Knee Arthroplasty)


Partial joint replacement is the use of an implant to replace a damaged area of joint tissue. The metal implant can create a smooth surface. This may improve joint performance and decrease pain. U

Resurfacing may be done on the hip, shoulder, or knee joints.

Reasons for Procedure

Cartilage is the protective surface of your joint. It allows smooth movement and cushions the bone. Damaged cartilage can limit joint movement and make it painful to do even basic movements. Osteoarthritis is the most common cause of this damage. It is the gradual wear and tear of joints over time. Less often, the damage is due to a trauma.

A partial replacement may be considered:

  • If other treatment options, have failed to improve function or pain. First line options include medicine, joint injections, and physical therapy.
  • If pain limits your activities and affects your quality of life.

A partial replacement tends to have less recovery time than a total hip or knee replacement. However, it is not appropriate for all people. Widespread joint damage may require a total joint replacement. The ligaments of the joint will also need to be intact.

Osteoarthritis of the Knee
Knee arthitis

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Possible Complications

Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:

  • Joint pain, stiffness, or instability
  • Loose joint
  • Dislocation
  • Excess bleeding
  • Infection
  • Blood clots
  • Nerve and/or blood vessel injury
  • Reaction to anesthesia
  • Lack of improvement in physical ability or less than expected

The area of the joint that is not repaired can still wear down. It may lead to additional surgery in the future.

Before your procedure, talk to your doctor about factors that may increase your risk of complications such as:

  • Smoking
  • Drinking
  • Chronic disease, such as diabetes or obesity

What to Expect

Prior to Procedure

Before surgery, you may need to have a physical exam. This will help identify any risk factors for surgery.

Your doctor will review previous tests. This may include previous:

Talk to your doctor about your medicine. You may be asked to stop taking some medications up to two weeks before the procedure.


The anesthesiologist will talk to you before your surgery. Common options for this surgery include:

Description of the Procedure

An incision will be made along the joint. Muscles, tendons, and ligaments will be carefully moved aside. The surgeon will move the joint to get access to the damaged area. The entire joint will be inspected. If damage is widespread the partial replacement may not be done. Your surgeon will talk to you before the surgery about the possibility of a total joint replacement.

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 will be placed on the opposite joint surface. (May not be done for shoulder surgery.) A plastic disc may be placed between the 2 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 may be placed over the incision.

How Long Will It Take?

1-3 hours

How Much Will It Hurt?

Anesthesia will prevent pain during surgery. Your knee will be painful in the first few days after surgery. Pain and discomfort can be managed with medicine. Managing pain will help your body heal faster.

Average Hospital Stay

The hospital stay is usually about 1-4 days. If you have any problems, you may need to stay longer. Some may go home on the same day as surgery.

Post-procedure Care

At the Hospital

Right after the procedure, you will be in a recovery room. Your blood pressure, pulse, and breathing will be monitored. Recovery may also include:

  • Pain medicine
  • Antibiotics to prevent infection
  • Medicine to prevent blood clots
  • X-rays to check the implants

You will be encouraged to put weight on your leg soon after surgery. Physical therapy will help you get started. This therapy will help to regain the range of motion and strength of the joint. The therapist will also help you understand how to use a walker, cane, or crutches.

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

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

There are also steps you can take to reduce your chances of infection such as:

  • Washing your hands often and reminding visitors and healthcare providers to do the same
  • Reminding your healthcare providers to wear gloves or masks
  • Not allowing others to touch your incisions

At Home

You may need a walker, crutches, or cane to help you walk. The devices will help support your joint until you feel able to walk on your own. The length of time you need assistance will depend on the joint, how much work is done, and your overall health.

It may take about 6 weeks before you can fully return to normal activity. Your return to work will depend on the physical needs of your job.

Call Your Doctor

It is important for you to monitor your recovery after you leave the hospital. Alert your doctor to any problems right away. If any of the following occur, call your doctor:

  • Pain that cannot be controlled with the medications you were given
  • Signs of infections, such as fever and chills
  • Signs of infection at the incision site, such as warmth, redness, or excess drainage
  • Worsening joint stiffness, pain, or instability
  • Numbness or tingling in your arms, fingers, legs, or toes

Call for emergency medical services right away for:

Pulmonary embolism, a blood clot that is lodged in the lungs, which may cause:

  • Shortness of breath
  • Rapid breathing
  • Chest pain that occurs when you breathe or cough
  • Spitting blood

Deep vein thrombosis, an obstructive blood clot (mainly in the leg), which may cause:

  • Leg swelling and tenderness
  • Pain in the groin or buttocks
  • Swelling in the thigh
  • Redness, warmth, or skin discoloration

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


Elective total hip arthroplasty. EBSCO DynaMed website. Available at: Updated July 3, 2018. Accessed April 21, 2018.

Osteoarthritis of the knee. EBSCO DynaMed Plus website. Available at: Updated March 15, 2018. Accessed April 21, 2018.

Shoulder joint replacement. Ortho Info—American Academy of Orthopaedic Surgeons website. Available at: Updated December 2011. Accessed November 10, 2017.

Unicompartmental knee replacement. Ortho Info—American Academy of Orthopaedic Surgeons website. Available at: Updated April 2016. Accessed April 21, 2018.

Last reviewed November 2018 by EBSCO Medical Review Board Warren A. Bodine, DO, CAQSM  Last Updated: 7/29/2018