The Evolution of Image-Free Robotic Assistance in Unicompartmental Knee Arthroplasty.

Semiautonomous robotic technology has been introduced to optimize accuracy of bone preparation, implant positioning, and soft tissue balance in unicompartmental knee arthroplasty (UKA), with the expectation that there will be a resultant improvement in implant durability and survivorship. Currently, roughly one-fifth of UKAs in the US are being performed with robotic assistance, and it is anticipated that there will be substantial growth in market penetration of robotics over the next decade. First-generation robotic technology improved substantially implant position compared to conventional methods; however, high capital costs, uncertainty regarding the value of advanced technologies, and the need for preoperative computed tomography (CT) scans were barriers to broader adoption. Newer image-free semiautonomous robotic technology optimizes both implant position and soft tissue balance, without the need for preoperative CT scans and with pricing and portability that make it suitable for use in an ambulatory surgery center setting, where approximately 40% of these systems are currently being utilized. This article will review the robotic experience for UKA, including rationale, system descriptions, and outcomes.