UKA surgery may reduce post-operative pain and have a shorter recovery period than a total knee replacement procedure,[1][2] particularly in people over 75 years of age.

[4] In comparisons with a more extensive surgical procedure called high tibial osteotomy, UKA has equal or better outcomes.

[3][2] Initially, UKAs were not always successful, because the implants were poorly designed, people needing the surgery were not thoroughly screened for suitability, and optimal surgical techniques were not developed.

[1][7][8] Also, choosing the best-suited people was emphasized to ensure that surgeons followed the indications and contraindications for partial replacement.

[1][2] UKA may be suitable for people with moderate joint disease caused by painful osteoarthritis or traumatic injury, a history of unsuccessful surgical procedures or poor bone density that precludes other types of knee surgery.

[1] The anterior cruciate ligament (ACL) should be intact,[11] although this is debated by clinicians for people who need a medial compartment replacement.

[7][12] The unicompartmental replacement is a minimally invasive option for people whose arthritis is isolated to either the medial or the lateral compartment.

The procedure offers several benefits for patients with a moderately active lifestyle, who have arthritis in just one knee compartment, and who are within normal weight ranges.

A partial replacement also causes minimal blood loss during the procedure, and results in considerably less post-operative pain.

The causes of long-term failure of UKAs include polyethylene wear, loosening of the implant, and degeneration of the adjacent knee compartment.

[2] Long-term studies reported excellent outcomes for UKA, partly due to subject screening,[18] minimizing the amount of bone that is removed,[19] and using the proper surgical technique.