Unicondylar knee replacement (UKA) is a viable alternative to high tibial osteotomy (HTO) and total knee replacement in the treatment of medial osteoarthritis of the knee. With the correct indication, the results of UKA and HTO are comparable.
In comparison with the results of total knee replacements, UKA leads to faster rehabilitation, superior postoperative range of motion, and higher postoperative activity levels. Despite the excellent long-term results, the survival rate is inferior to the results of total knee replacement. The major causes for failure are progression of osteoarthritis in the lateral and patellofemoral joint as well as the loosening of the tibial component.
The conversion to total knee replacement can mostly be performed without problems. However, the expected results are inferior to primary total knee replacement and the reported revision rates are higher.