Robotically Assisted Anterior Closing Wedge High Tibial Osteotomy: A Surgical Technique Proof of Concept

Increased posterior tibial slope is a risk factor for anterior cruciate ligament reconstruction graft failure. In revision anterior cruciate ligament surgery, anterior closing-wedge high-tibial osteotomy (ACW-HTO) addresses increased tibial slope. ACW-HTO is technically challenging in accurately executing the desired bony cuts and degree of correction. Risks include posterior neurovascular injury, hinge fractures, coronal-plane alterations, and over/under alignment correction. We present a technique leveraging the accuracy of a computed tomography-based robotic knee arthroplasty system to plan and execute precise bone cuts for ACW-HTO. We carried out 3 ACW-HTO scenarios on a Sawbones model; supratubercle, infratubercle, and combined coronal plane osteotomy. After Sawbones computed tomography scanning the software was used to plan osteotomy trajectories. The tibial baseplate cut for knee arthroplasty was adapted to perform 2 angulated ACW-HTO bone cuts, rotated and positioned upon the desired posterior hinge point. Bone cuts were successfully executed using a robotically assisted saw, registering cuts to a high accuracy. Bony registration is permitted through the surgical approach for an ACW-HTO referencing only the anterior tibial cortex with 0.2-mm accuracy. This delivered excellent precision, matching planned corrections. Robotic haptic boundaries ensured safe limits posteriorly, hinge-point maintenance and coronal-plane control.