Design and Development of 5-Axis Cranial Implant Laser Cutting System

Cranioplasty is a procedure for skull reconstruction after removal of bone defects such as tumors. Recent approaches for cranioplasty involve the use of customized cranial implants (CCIs). A challenge in performing the cranioplasty with CCI is that the actual size/shape is unknown until the tumor is removed. Often the procedure is performed in two stages. After removing the cranial defect, the surgeon works with an implant manufacturer to develop a CCI using computer-aided design and manufacturing (CAD/CAM) techniques. The CCI attachment to the skull will then require a second surgery. We recently proposed a robot-assisted single-stage cranioplasty. For conventional, single-stage CCI, the CCIs are usually made in oversized profiles and require manual intraoperative modification by the surgeon. The challenge, however, is that for complex cases the surgeon may spend a long time reshaping the CCI. This paper presents the development of a 5-axis laser cutting machine that has the capability of automatically shaping CCI profiles during single-stage cranioplasty. Preliminary results indicate a superior fit with only mm size gaps between the implant and the remaining skull.