A partial knee replacement is surgery to replace either the inside (medial) or outside (lateral) parts of the knee. It is called a partial replacement because only one part of the damage knee is replaced.
Unicompartmental knee arthroplasty; Knee replacement – partial; Unicondylar knee replacement; Arthroplasty – unicompartmental knee; UKA; Minimally invasive partial knee replacement
Partial knee replacement surgery removes damaged tissue and bone in the knee joint and replaces the area with a man-made implant, called a prosthetic.
Before surgery, you will be given anesthesia, which is medicine that blocks pain. You will have one of two types:
General anesthesiamakes you unalert and unable to feel pain.
spinal or epidural) anesthesia numbs you below your waist. You will also receive medicines to make you relax or feel sleepy.
The surgeon will make a cut over your knee.This cut is about 3 to 5 inches long.
Next, the doctor examines the entire knee joint. If there is damage to more than one part of your knee, you may need a total knee replacement. Most of the time, however, this is not needed.
The damaged bone and tissue is removed.
A man-made part made of plastic and metal is placed into the knee.
Once it is in the proper place, it is secured with bone cement.
The wound is closed with stitches.
Why the Procedure Is Performed
The most common reason to have a knee joint replaced is to relieve severe arthritis pain. Your doctor may recommend knee joint replacement if you have:
- Symptoms of knee arthritis, including knee pain that keeps you up at night or prevents you from doing daily activities
- Knee pain that continues despite other treatments
You will need to understand what surgery and recovery will be like.
Partial knee arthroplasty may be a good choice if you have arthritis on only one side of the knee, and you:
Are older, thin, and not very active
Do not have very bad arthritis on the other side of the knee or under the kneecap
Have only minor deformity of the knee
Still have good range of motion in the knee
However, most people with knee arthritis have a surgery called a total knee arthroplasty (TKA).
Knee replacement is usually done in people age 60 and older.
Risks for anesthesia include:
- Problems breathing
- Reactions to medications
Risks for any surgery include:
Risks for UKA include:
- Fluid buildup in the knee joint
- Nerve and blood vessel damage
- Pain with kneeling
Reflex sympathetic dystrophy(rare)
Before the Procedure
Always tell your doctor or nurse what drugs you are taking, including herbs, supplements, and medicines bought without a prescription.
During the 2 weeks before your surgery:
- Ask your doctor which medicines you can still take on the day of your surgery.
- You may be asked to stop taking medicine that make it harder for your blood to clot. These include aspirin, ibuprofen (Advil, Motrin), naproxen (Naprosyn, Aleve), and other drugs.
- You may need to stop taking any medicines that weaken your immune system, including Enbrel and methotrexate
- If you have diabetes, heart disease, or other medical conditions, your surgeon will ask you to see the doctor who treats you for these conditions.
- Tell your doctor if you have been drinking a lot of alcohol (more than one or two drinks a day).
- If you smoke, you need to stop. Ask your doctor or nurse for help. Smoking slows healing and recovery.
- Let your doctor know if you get a cold, flu, fever, herpes breakout, or other illness before your surgery.
- You may want to visit a physical therapist before surgery to learn exercises that can help you recover.
- Practice using a cane, walker, crutches, or a wheelchair. You will need to learn how to:
- Get in and out of the shower
- Go up and down stairs
- Sit down to use the toilet and stand up after using the toilet
- Use the shower chair
On the day of your surgery:
- You will usually be asked not to drink or eat anything for 6 – 12 hours before the procedure.
- Take the drugs your doctor told you to take with a sip of water.
- Your doctor or nurse will tell you when to arrive at the hospital.
After the Procedure
Most patients go home the day after surgery.
You can put your full weight on your knee right away.
After surgery, you will be encouraged to do as much as you can for yourself. This includes going to the bathroom or taking walks in the hallways, always with someone helping you.
Most patients recover quickly and have much less pain than they did before surgery. People who have a partial knee replacement recover faster than those who have a total knee replacement.
Many patients are able to walk without a cane or walker within 3-4 weeks after surgery. You will need physical therapy for 4 to 6 months.
Most forms of exercise are okay after surgery, including walking, swimming, and biking. However, you should avoid high-impact activities such as jogging.