A Novel Articulating Bone Cutting Tool for Minimally Invasive Craniosynostosis Surgery

Abstract

Abstract. Craniosynostosis involves early fusion of cranial sutures, resulting in an abnormal head shape and functional issues such as elevated intracranial pressure. Treatment involves surgery to correct the head shape and to allow unrestricted brain growth. This work aims to overcome the restrictions of current instruments by developing a novel articulated bone cutting tool for minimally invasive craniosynostosis surgery. A handheld tendon-driven tool with a bending section was developed to enhance reachability along the skull. The tool comprises a driving unit, a bending section attached to an end-effector, and a flexible endoscope. The prototype was developed and characterized to validate its accuracy, stiffness, bone-cutting capability, and reachability. A prototype was developed with a high reachability of 72.2%, 71.6%, 78.4% (length of the osteotomy/total planned path) using sagittal, metopic, and unicoronal craniosynostosis skull models, respectively. The tool demonstrated low deflection (≤5 mm for all configurations except for 0 deg bending) under 5 N external force and is capable of cutting bone-like materials with varying bending angles (range from 45 deg to 90 deg). These results indicate the potential of the bone-cutting tool to provide a paradigm shift in the treatment of craniosynostosis, expanding the benefits of minimally invasive approach to more patients.