Christian Rasche

Management of cranial and craniofacial bone defects with prefabricated individual titanium implants: follow-up and evaluation of 166 patients with 169 titanium implants from 1994 to 2000

AbstractObjective The TICC (Tomography, Image processing, CAD, CAM) processing chain developed at the Ruhr-University Bochum in Germany has already been established since several years for the reconstruction of large pre-existing posttraumatic skull defects with individual prefabricated implants made of pure titanium. So far, more than 500 titanium implants have been inserted with great success at more than 60 clinical centres worldwide. The aim of our study was to evaluate all implants inserted between 1994 and 2000. Materials and Methods The study describes the clinical experience with 166 patients receiving 169 skull implants between 1994 and 2000. All 169 implants were measured and categorized in the CAD system in terms of size and anatomical localization. The surgical and radiological reports of the patients were evaluated. Sixty patients operated at the university hospital in Bochum and nearby were clinically reviewed describing scars, position of the implants and cosmetic results. Questionnaires of 131 patients were analyzed regarding the postoperative quality of life distinctly. Results The study shows constantly good to excellent results intraoperatively as well as postoperatively regarding complications, fit of the implants and the clinical follow-up. In particular the enquiry of the patients shows that titanium skull implants improve quality of life. Conclusion High precision and easy handling as well as a low complication rate and the high contentedness of the patients make the individual titanium skull implants valuable for cranioplasty, especially in complicated applications with very large defects, multiple previous operations and additional irradiations. Even in these difficult cases predictable results are possible.

Single-step robot guided bone resection and individual reconstruction of the skull

The TICC (Tomography Image processing CAD-CAM) processing chain allows the supply of existing craniofacial defects with individually prefabricated implants based on helical CT data [1, 2]. In combination with individual templates single-step bone resection and reconstruction is available [3, 4, 5, 6]. New developments in navigation and robotics allowed a robot guided bone resection according to the preoperative planning with the CAD system [7, 8, 9, 10]. This study shows results of resection experiments on ovine cadaver heads.

FORMGEBUNG DEGRADIERBARER WERKSTOFFE MIT HILFE DER VERFAHRENSKETTE ZUR FERTIGUNG INDIVIDUELLER CAD/CAM-IMPLANTATE

Die an der Ruhr-Universität Bochum entwickelte Verfahrenskette zur präoperativen Herstellung individueller Schädclimplantatc basiert auf Computertomographie (CT)-Daten des Patienten und bedient sich Computer Aided Design (CAD) und Computer Aided Manufacturing (CAM) [1,2, 3]. Dabei ist die Verfahrenskctte auf den Werkstoff Titan zugeschnitten und optimiert, erlaubt jedoch grundsätzlich auch die Verarbeitung anderer Materialien durch Fräsen oder in einer Hohlform [4]. Biodegradierbare Werkstoffe wie Polymere sind diesbezüglich von besonderem Interesse, da sie als Trägersubstanz für osteoinduktive Proteine eine Knochcnncubildung bei gleichzeitiger Degradation es Carriers ermöglichen [5, 6, 7].

EIN GRADIERTER KOMPOSITWERKSTOFF FÜR DEN EINSATZ IM BEREICH DES HIRN- UND GESICHTSSCHÄDELS

For the reconstruction of complex skull defects with individual prefabricated CAD/CAM-implants titanium is well established as bone substitution material. The aim of our studies was to optimize a composite material from polyesters and calcium phosphate. Therefore two different operating procedures (hot pressing and gas-flushing) were combined. As a result the graded composition and porosity of the implants allow a spatial guided degradation progress and cell ingrowth. First biocompatibility tests in vitro with primary human osteoblasts showed a much better pH-characteristic and a better biocompatibility of the composites in comparison with the pure polymers. Degradation experiments in vitro confirmed the different expected degradation rates of the composite materials. As a next step in vivo experiments in ovine skulls are in progress.