Diagnosis and indications for treatment of unicompartmental arthritis.

Unicompartmental knee arthroplasty (UKA) is a reliable operation for isolated unicompartmental arthritis. A comprehensive understanding of the limitations of UKA is crucial for success in the young patient. Obesity may impact implant longevity; however, acceptable results can be achieved with precise component implantation and careful patient selection. UKA for degenerative medial compartment arthritis with attritional anterior cruciate ligament (ACL) rupture is generally contraindicated. However, concomitant ACL/UKA reconstruction is a dependable treatment for early posterior-medial compartment arthritis caused by an acute ACL rupture. Regardless of its limitations, the functional benefits and limited morbidity of UKA make it an appealing treatment option for unicompartmental disease.