The authors' objective in this project was to replace current state-of-the-art manual methods for preoperative production (i.e., prefabrication) of large-format (>100 cm2) cranioplasties with a system for computer-aided design and direct computer-aided manufacture of the implant's shape. This system uses standard 3D CT data, requires no specialized training, and produces an accurately fitting cranioplasty that can be recast in the physician's material of choice (e.g., polymethylmethacrylate [PMMA] or pre-bent titanium plating). The authors begin by locating the cranial defect margin on a skull surface image generated from a 3D head CT-scan. A right-to-left mirrored or average 3D skull surface template image is then fit to the patient's skull surface image. The area around the defect is cut out and stitched to the previously isolated defect margin. This defect-filling surface is then tapered and 3D printed. The 3D printed implant model is then recast in a biocompatible material. Manually generated cranial implants produced for five patients were compared with implants resulting from this new computer-based method. All five computer-generated implants were better fitting and more cosmetically suitable than the manually generated skull plates received by these patients. These well-fitting implants are more likely to protect the brain from trauma and infection. Therefore, the authors conclude that their new production method provides a better result with less expense than current methods for preoperative or intraoperative fabrication of large-format cranioplasties.
*Department of Neurological Surgery and the Research Institute, University Hospitals of Cleveland, and Department of Neurological Surgery, Case Western Reserve University, Cleveland, Ohio, †(at the time of this project) Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, Ohio, ‡(currently at) Osteoplastics Corporation, Solon, Ohio
Address correspondence to David Dean, Department of Neurological Surgery, Hanna House 5th Floor, M.S.# 5042, University Hospitals of Cleveland, 11100 Euclid Avenue, Cleveland, OH 44106 USA; e-mail: DavidDean@cwru.edu
Sources of Support: Partial support was derived from NIH SBIR Grant# R43-DE013786, “Image-guided reconstruction of neurocranial deficit.” Partial support was provided by the Research Foundation, Department of Neurological Surgery, UHC/CWRU.
Disclosure Statement: Data obtained from human subjects was done under an approved University Hospitals of Cleveland Internal Review Board human subjects protocol. The first author is a co-founder of, consultant to, and shareholder in Osteoplastics Corp., Cleveland, OH. Osteoplastics is the recipient of the cited SBIR grant that partially supported the study reported here. Osteoplastics provided this support to the first author's Department at Case Western Reserve University via an NIH consortial subcontract.
This work was first presented at Computer Assisted Surgery 2001, October 12 in Nürnberg, Germany.