The MAKO robotic-arm knee arthroplasty system

Introduction The Mako robotic arm knee arthroplasty system was initially indicated in unicompartmental knee arthroplasty followed by bicompartmental and total knee arthroplasty techniques. The system utilizes three elements: (1) Pre-op 3D CT based planning and image based intra-op navigation. (2) Pre-resection implant modifications with integrated alignment, implant position and gap data, and (3) A semi-constrained robotic arm assisted execution of bone resection with "haptic" boundaries, and cemented implants. Materials and methods This paper evaluates variable pre-op implant placement, and anatomic reference positioning; data entry with incorporation of alignment, implant congruency through range of motion, and gaps; bone resection with "haptic" boundaries, and final implant evaluation with kinetic sensors. Results The Mako system allowed for improved implant placement utilizing CT guidance, bone resection accuracy, flexibility for functional implant placement with gap balancing. When combined with kinetic sensors, there was improved rotation and soft tissue balance. Conclusion The MAKO robotic system can assist the surgeon with anatomic landmarks, provides the flexibility for independent gap balance through implant and alignment refinement, and three-dimensional soft tissue balancing data to achieve functional stability. Registry data has shown improved outcome survivorship irrespective of the surgeons' volumes and learning curves.