The anterior cruciate ligament-deficient knee and unicompartmental arthritis.

Treatment of medial and lateral compartment arthritis in the anterior cruciate ligament (ACL)-deficient knee remains a topic of debate among orthopedic surgeons. This article discusses the treatment options for the ACL-deficient knee with unicompartmental arthritis and provides a rationale for clinical decision making in this difficult group of patients. Unicondylar knee arthroplasty (UKA) is a viable option in a select group of patients to decrease pain and maintain an active lifestyle. When performing a UKA in an ACL-deficient knee, it is important to manage appropriate expectations for a successful outcome.