A total knee replacement is a common and successful surgical procedure that can relieve the pain of knee arthritis and help you regain your active lifestyle.
But if arthritis has damaged only one compartment of your knee, you can gain similar benefits from a partial knee replacement, but with a faster recovery period and other short-term advantages. A recent study suggests that both types of knee replacements offer comparable long-term results.
“There are some studies showing that up to 50% of patients could qualify for partial knee replacement, meaning they have arthritis isolated to one compartment,” says Trevor Murray, MD, a Cleveland Clinic orthopedic surgeon. “I’m a believer in partial knee replacements, and I tell my patients that I think they are more likely to achieve a higher level of function after a partial.”
If you’re a candidate for a knee replacement, ask if a partial knee replacement is appropriate for you. Just keep in mind that your surgeon’s experience and the work you put in to improve your knee function before and after any type of knee replacement are vital to achieve the best outcomes.
What Is Partial Knee Replacement?
The knee is composed of three compartments: the medial (inside), lateral (outside) and patellofemoral (front of the knee between the kneecap and thighbone). A total knee replacement replaces all three components with a metal and plastic implant and also removes the anterior cruciate ligament, which helps stabilize the knee.
Also known as a unicompartmental knee replacement, a partial knee replacement entails the resurfacing of only one knee compartment (usually the medial compartment), and all ligaments are left intact.
Who Is a Candidate?
Knee replacement surgery is used primarily to treat painful osteoarthritis in the knee that no longer can be managed successfully with nonoperative treatments, such as physical therapy; bracing; topical nonsteroidal anti-inflammatory drugs (NSAIDs) like diclofenac (Voltaren Arthritis Pain gel, Pennsaid); oral NSAIDs, such as ibuprofen (Advil, Motrin) and naproxen (Aleve); and injections of corticosteroids or hyaluronic acid (viscosupplementation).
A partial knee replacement makes sense only if your arthritis is confined to one knee compartment. Dr. Murray notes that the surgery is an especially good option for more active individuals who engage in higher-level activities (e.g., racket sports, skiing), as well as older patients, “because there is no doubt that it’s much less traumatic, much less invasive and has a much smaller hit to their overall system.”
Benefits and Risks
Partial knee replacement may have several advantages over total knee replacement, Dr. Murray says:
- Because less of the knee is affected, patients undergoing partial knee replacement generally have a lower risk of complications such as infection, blood clots, and nerve injury
- They also typically enjoy a shorter recovery period.
- Many patients report having a knee that feels “more normal” after a partial knee replacement versus total knee replacement, Dr. Murray says.
In the TOPKAT trial, 962 people with medial compartment osteoarthritis were randomly assigned to partial knee replacement or total knee replacement. At 10 years, researchers found no differences between the two in terms of clinical outcomes and similar rates (9%) of reoperations, including revision surgery (i.e., repeat operations to replace a failed implant). However, partial knee replacement was more cost-effective than total knee replacement, being associated with higher health benefits and lower healthcare costs, the study found (Lancet Rheumatology, February 2026).
“What’s important about this study is the very comparable revision rates at 10 years,” Dr. Murray says. “You have a procedure [partial knee replacement] that, in the early term, is quicker, has faster, easier recovery and has potentially higher functional outcomes without the cost of shorter longevity.”
Along with the benefits come some potential risks/limitations associated with partial knee replacement. Keep these key points in mind:
- With a partial knee replacement, you face the possibility that arthritis will advance to your other knee compartments, thereby necessitating a total knee replacement. Fortunately, converting a partial knee replacement to a total knee replacement is relatively straightforward and less challenging than revising a total knee replacement, Dr. Murray says.
- If during the partial knee replacement your surgeon notices arthritis in your other compartments that wasn’t visible on imaging, he or she may convert it to a total knee replacement.
“You’ll get good function with both types. That’s why we do them,” Dr. Murray says. “In either case, the key is to do the procedure that’s appropriately indicated. Patients, regardless of whether it’s a partial or total knee replacement, should certainly expect a decrease in pain and improvement in function.”
The Procedure: What to Expect
Your physical condition going into surgery will contribute greatly to your success afterward. Your physician and/or a physical therapist will recommend “prehabilitation” exercises that, as much as tolerable, strengthen the muscles that support and keep your knee mobile—all of which will help speed up your recovery after surgery. Staying as active as possible also can help you shed unwanted pounds and ease strain on your knees.
Your doctor will advise you on any medications you’ll need to stop taking in the hours and days leading up to surgery. Partial knee replacement is often performed using regional (e.g., spinal) anesthesia, which numbs you from the waist down. Another option is general anesthesia, in which you’re put to sleep.
During the operation, the surgeon makes a small incision to access the diseased knee compartment. He or she removes the damaged cartilage and bone from the femur and tibia in the diseased knee compartment and implants the prosthetic components. The surgery typically takes about an hour to complete. Some surgeons perform the operation using robotic assistance.
Recovery and Rehabilitation
You’ll undergo physical therapy in the days and weeks after your surgery, and your doctor will prescribe pain medications, as needed.
Dr. Murray says he expects his partial knee replacement patients to go home the same day as their surgery (many total knee replacement patients do, as well), use a walker, cane, or other assist device for two weeks (versus three to four weeks for total knee replacement recipients) and achieve 80% to 90% recovery at two to three months (compared with four to five months for total knee replacement patients). He adds that people who undergo either type of knee replacement may continue to see improvements for up to a year after surgery.
