Indications for unicompartmental knee arthroplasty and rationale for robotic arm-assisted technology.

Unicompartmental knee arthroplasty (UKA) is an effective surgical treatment for focal arthritis when appropriate selection criteria are followed. Although results can be optimized with careful patient selection and use of a sound implant design, two of the most important determinants of UKA performance and durability are how well the bone is prepared and components aligned. Study results have shown that component malalignment by as little as 2 degrees may predispose to implant failure after UKA. Conventional cutting guides have been relatively inaccurate in determining alignment and preparing the bone surfaces for unicompartmental implants. Computer navigation has improved component alignment to an extent, but outliers still exist. The introduction of robotics capitalizes on the virtues of computer navigation but couples the planning and mapping of navigation with robotic techniques for bone preparation. Robotic technology is fostering substantially improved precision and component alignment in UKA, even when using minimally invasive soft-tissue approaches.