Robotic Arm-assisted Augment Preparation (RAAP-Technique) During Total Knee Arthroplasty

Modular metal augments are commonly used to reconstruct bony defects during complex primary and revision total knee arthroplasties. The slot for placing an augment is usually prepared using an intramedullary jig and conventional instruments, even during robotically assisted total knee arthroplasty. We report a robotic arm-assisted augment-preparation (RAAP) technique to reconstruct uncontained bony defects using modular metal augments. In this technique, a saw-based robotic arm is utilized to precisely resect the base of the bony defect to accommodate the modular metal augment of appropriate size. The method described in this study avoids the need for conventional revision instrumentation to perform this part of the surgery. Surgery can be completed without removing the robotic array pins. Hence, the robotic system can be retained until the end of the surgery, enabling the monitoring of the final alignment robotically, even during and after the polymerization of the cement. A short case series utilizing this method is also presented.