Robotic technology: current concepts, operative techniques and emerging uses in unicompartmental knee arthroplasty

Unicompartmental knee arthroplasty (UKA) is associated with improved functional outcomes but reduced implant survivorship compared to total knee arthroplasty (TKA). Surgeon-controlled errors in component positioning are the most common reason for implant failure in UKA, and low UKA case-volume is associated with poor implant survivorship and earlier time to revision surgery. Robotic UKA is associated with improved accuracy of achieving the planned femoral and tibial component positioning compared to conventional manual UKA. Robotic UKA has a learning curve of six operative cases for achieving operative times and surgical team comfort levels comparable to conventional manual UKA, but there is no learning curve effect for accuracy of implant positioning or limb alignment. Robotic UKA is associated with reduced postoperative pain, decreased opiate analgesia requirements, faster inpatient rehabilitation, and earlier time to hospital discharge compared to conventional manual UKA. Limitations of robotic UKA include high installation costs, additional radiation exposure with image-based systems, and paucity of studies showing any long-term differences in functional outcomes or implant survivorship compared to conventional manual UKA. Further clinical studies are required to establish how statistical differences in accuracy of implant positioning between conventional manual UKA and robotic UKA translate to long-term differences in functional outcomes, implant survivorship, complications, and cost-effectiveness.