Evolving technology in unicompartmental knee arthroplasty

Introduction

The evolution of the basic technical principles of unicompartmental arthroplasty design and implantation are discussed in Chapters 1 , 3 , 6 and 7 . These should endure for years to come. Innovative technological advances, however, will appear, evolve, and find their place in the years to come. This final chapter will discuss current evolving technologies such as robotic component positioning, patient-specific instruments and prosthetic components, and cementless fixation.

Robotic component positioning

Innovative technologies have been introduced to improve component positioning with the goal of increasing the longevity of unicompartmental knee arthroplasty (UKA). Several systems have been developed including the MAKO Robotic Tactile Guidance System, the MAKO Robotic Arm Interactive Orthopedic System (MAKO RIO), Navio Precision Free-Hand Sculptor, ROBODOC, Acrobot, and UniAlign, with MAKO commanding the largest market share in robotic-assisted joint arthroplasty at the time of this publication.

Several studies have shown that robotic-assisted surgical procedures result in higher accuracy of component positioning and lower incidence of alignment outliers. In one randomized control trial, 120 patients were randomly assigned to robotic-assisted surgery or conventional UKA, and it was found that the proportion of patients within 2 degrees of the preoperative target position was significantly higher in robotic-assisted surgery for femoral component sagittal, coronal, and axial position, and tibial component sagittal and axial position. In a metaanalysis of robotic-assisted versus conventional UKA, robotic-assisted UKA was similarly found to have significantly lower mechanical axis and tibial component position deviations compared with conventional UKA. However, it has also been shown that an experienced, high-volume surgeon can meet or exceed robotic accuracy for tibial alignment in manual UKA.