Haptic Virtual Fixtures To Guide Fibula Osteotomies In Mandible Reconstruction Surgery

When a tumour is found on the mandible, fibula free-flap mandibular reconstruction is often performed where the cancerous area is removed and replaced with the patient’s bone from the fibula and soft tissue from the calf. Fibula bone segments used to reconstruct the mandible must closely match the removed sections of the mandible to ensure the optimal surgical outcome. In the current practice, surgical design and simulation of the reconstruction based on medical imaging data, 3D planning, and rapid-prototyped surgical guides ensure that the surgical plan is accurately followed in the operating room (OR). However, rapid prototyped guides are time-consuming to manufacture. As an alternative, haptic virtual fixtures can be used in surgery to constrain surgical tools to predefined regions or trajectories. The resulting haptic assistance can guide surgeons during fibula segmentation to ensure that fibula osteotomies are segments that correspond to the mandible resection according to the reconstruction surgical plan. In this paper, the feasibility and repeatability of using virtual haptic fixtures were tested experimentally on rapid prototyped fibula models. A haptics-enabled robotic system was used to guide participants’ hands to the correct position and orientation in space according to the surgical plan using haptic feedback. The results based on ten participants cutting fibula replicas suggest that the accuracy achieved with the system was 3.7mm. Improvement in the registration process and registration accuracy, extended reach of the robot arms, and more intuitive virtual fixtures would be required before adoption for clinical use. However, this paper illustrates a workflow for integrating haptic feedback into the fibula mandible reconstruction procedure, identifies obstacles related to clinical implementation, and demonstrates how haptic feedback can be used as a guidance method to assist users complete fibula osteotomies.