Uni-Knee Partial Replacement
Frank Casagrande, Uni-knee partial knee replacement patient
The Uni-Knee approach to partial knee replacement can get patients back to doing what they want more quickly. In our region, it's available at The Orthopedic Hospital.
The minimally invasive unicompartmental knee arthroplasty (UKA) is a surgery in which either the inside (medial), outside (lateral) or patello femoral (front) compartment of the knee is replaced. UKA is also called partial knee replacement because only one part of the damaged cartilage and bone is removed and replaced with a small implant. This is in comparison to the traditional procedure, during which all cartilage is removed from the knee joint and replaced with a metal and plastic implant.
UKA requires only a small incision, which results in less blood loss and a shorter recovery period. A 3-inch incision in needed for the UKA, compared to an 8-inch incision for the traditional procedure. Patients undergoing the UKA do not need to worry about blood loss, whereas patients undergoing a traditional operation usually give blood preoperatively in case a blood transfusion is needed after surgery.
Patients who undergo the UKA at TOH are usually discharged the same day and require minimal therapy. Patients undergoing a total knee replacement usually spend three to four days in the hospital after surgery, require several weeks of therapy and sometimes, they also require a short stay in an inpatient rehabilitation facility.
Patients who qualify for the UKA cannot have widespread arthritis in the joint. Unfortunately, for a lot of patients, by the time they seek surgical management as the solution to their condition, the disease is too far along, eliminating them from consideration for the UKA.
Patients who qualify for the UKA:
- Are 40 years of age or older
- Are not severely obese
- Have severe arthritis of the knee in a confined area with pain that limits activity
- Have intact ligaments, specifically the ACL
- Have tried conservative treatments, such as cortisone injections, medications, strengthening exercises and weight loss, which have consistently failed
Long-Term Results and Possible Complications
Patients who meet the criteria for the UKA have good long-term results. Studies show that more than 90 percent of UKA implants are still in place and functioning more than 10 years later.
Overall benefits of the UKA over total knee replacement include:
- Better range of motion
- Less invasive procedure
- Less pain and swelling postoperatively
- Less therapy required, if any
- More normal knee function
- No need for blood transfusions due to minimal blood loss
- Quicker recovery
Five to 10 percent of patients may develop arthritis in another area of the knee or wear out the implant, or the implant may come loose inside the knee. These situations require additional surgery, and possibly, the conversion to a total knee replacement.
Other potential complications from UKA include anesthesia side effects, blood clots and infection. Patients should discuss all of these possibilities with their surgeon prior to surgery.