Revision of the Failed Unicompartmental Knee Arthroplasty

Unicompartmental knee arthroplasty (UKA) is a popular procedure for focal osteoarthritis involving a single compartment of the knee. Despite good intermediate-term results and evidence that long-term survivorship approaches that of total knee arthroplasty, there remains concern about the durability of the construct, and the potential complexity of reconstruction following ultimate failure of a UKA. Modern designs that focus on bone preservation and proper alignment of the implants result in lower failure rates and less bone loss associated with such failures. Consequently, evidence suggests that when a unicompartmental replacement has become symptomatic, it can be successfully and more readily revised to total knee arthroplasty with excellent results. Understanding the mode of failure and the resultant bone and ligamentous defects guides reconstructive options. An algorithmic approach to the failed UKA is most likely to give rise to a successful outcome.