Accuracy of Robotic Arm Assisted Total Hip Replacement Planning Tool

Abstract

Background: Preoperative templating is an integral part of planning a successful total hip arthroplasty (THA), and helps minimise complications that can arise both intraoperatively and postoperatively. The aim of our study is to determine the reliability of the robotic arm assisted (MAKO fully enhanced) total hip replacement surgical system as a surgical planning tool (not to validate the robot in its execution as it has previously been done) in comparison to conventional acetate and digital templating. Method: The planning stages of fifty consecutive uncemented THA performed by a single robotic orthopedic surgeon was analyzed against what was achieved during the surgery. The variables analyzed were cup inclination, cup anteversion, combined anteversion, hip length, hip combined offset, femur size, femur component neck angle and cup size. Results: There was a significant correlation between planned and actual results. The component sizes were planned to accuracy within one size in 100% of femurs, 100% of femur neck-shaft angles and 98% of cups. Cup inclination, anteversion and combined anteversion were planned to accuracy within three degrees in 84%, 96% and 94% of cases respectively. Hip length and combined offset were planned to accuracy within three millimeters in 88% and 78% of cases respectively. Conclusion: The robotic arm assisted total hip replacement surgical system is a predictable and accurate planning tool and is superior to conventional acetate and digital templating. Level of evidence: Level III