Is patella facet arthritis a contraindication to unicompartmental knee arthroplasty: Current concepts

Medial unicompartmental knee arthroplasty (UKA) has increased in popularity for the ​treatment of end-stage anteromedial osteoarthritis in part secondary to its quicker recovery, improved function, and decreased risk of medical complications over total knee arthroplasty (TKA). However, despite the success of medial UKA, dilemma still exists over certain patient characteristics as to suitability for undergoing the procedure. In addition to patient age, body mass index (BMI), and the presence, or lack thereof, of an anterior cruciate ligament (ACL), one of the most contentious issues surrounding suitability for medial UKA is the preoperative status of the patellofemoral joint (PFJ). This review aims to look at the historical factors leading to the current dilemma as well as recent evidence surrounding anterior knee pain and preoperative PFJ arthritis on the survivability and outcomes of medial UKA. This article will also evaluate other PFJ factors possibly affecting the outcome of medial UKA such as lateral patellar subluxation and lateral facet grooving, future perspectives that may influence the utilization of medial UKA such as cementless implants, and the choice of mobile versus fixed bearing articulations.