Partial knee replacement surgery can help manage arthritis pain that hasn’t responded to other treatments. It involves the replacement of a damaged part of your knee joint. It has a shorter recovery time than full knee replacement surgery but isn’t right for everyone.
Knee replacement is a surgical procedure where damaged bone and cartilage are removed from your knee and replaced with an artificial joint. Knee replacements may be recommended if you have chronic pain that hasn’t responded to more conservative treatments.
Knee replacement surgery can be total or partial. In a partial knee replacement, a surgeon only replaces the damaged part of your knee joint.
Partial knee replacements are also known as:
- unicompartmental knee replacement
- unicondylar knee arthroplasty
- partial knee resurfacing surgery
Partial knee replacements are
A partial knee replacement is most often needed to treat osteoarthritis but is also used for other conditions such as osteonecrosis. But a partial knee replacement is only appropriate if you have damage to only one part of your knee joint.
The three components of your knee that this surgery can impact are:
- the medial or inside compartment
- the lateral or outside compartment
- the patellofemoral compartment, the part behind your kneecap and in front of your thighbone
Traditionally, a partial knee replacement has been
- have osteoarthritis in one compartment of their knee
- are older than 60 years of age
- have a body weight under 180 pounds
- don’t perform intense activities
- don’t have inflammatory arthritis
Researchers are continuing to examine who might benefit from a partial knee replacement, and guidelines are still evolving. Recent
Doctors or healthcare professionals generally only recommend a partial knee replacement if you don’t get pain relief from more conservative treatments such as:
You may not be eligible for a partial knee replacement if you have:
- inflammatory arthritis
- ligament damage
- significant knee stiffness
Here’s a general idea of what you can expect before, during, and after partial knee replacement surgery.
It’s important to tell the surgeon about all the medications and supplements you’re taking before your procedure, as some may increase your risk of complications.
Before your surgery begins, you’ll receive either general anesthetic or epidural anesthetic.
General anesthetic is given through an intravenous (IV) line and puts you in a sleep-like state. If you have general anesthetic, you likely won’t be able to eat within 6 hours or drink within 2 hours of your procedure.
Epidural anesthetic is given through a needle inserted into your spine that blocks pain below your waist. You’ll be conscious but won’t be able to feel any pain in your knee or legs.
During the procedure
Partial knee replacement surgery usually lasts between 1 to 2 hours. A partial replacement usually involves the following steps:
- The surgeon will make an incision at the front of your knee and examine the three components to make sure the damage is limited to one component.
- If the damage is limited to one component, the surgeon will use a special saw to cut the cartilage from the damaged part of your knee.
- They’ll replace the cartilage with metal coverings that make up the surfaces of the joint. These coverings are usually attached to your bone with cement.
- The surgeon will apply a polyethylene spacer between the metal coverings to allow them to glide together smoothly.
- Once everything is in place, the surgeon will close the incision with stitches.
Immediately after your procedure, you’ll be taken to the recovery room for monitoring. You generally need to spend about 1 or 2 days in a hospital. But in some cases, you can go home on the same day.
A partial knee replacement generally has a shorter recovery time than a total knee replacement. It’s normal to have some pain afterward. You may be able to manage your pain with nonsteroidal anti-inflammatory drugs (NSAIDs), or you may need stronger pain management drugs.
You’ll be encouraged to start putting weight on your knee as soon as you safely can. You may need assistive devices, such as crutches or a walker, in the first few days or weeks to help you move around safely.
A partial knee replacement generally has a lower complication rate than a total knee replacement. According to a 2021 study, the complication rate for a partial knee replacement is 16.3%, while it’s 20.1% for a total knee replacement.
Complications of a partial knee replacement can include:
- blood clots
- blood vessel or nerve injury
- continued pain
- reaction to the anesthetic
- the need for another surgery
- arthritis progression
A partial knee replacement may be an appropriate option if you only have damage to one part of your knee joint. It’s generally recommended if you don’t get pain relief from more conservative treatments such as physical therapy, joint injections, and anti-inflammatory medications.
A partial knee replacement offers some benefits over a total replacement such as a faster recovery time and a lower risk of complications. But it does have a higher risk of possibly needing revision surgery in the future. A doctor can help you weigh the pros and cons of each option.