gms | German Medical Science

Objective: The creation of a satisfactory cosmetic outcome in the repair of cranial defects relies mostly on manual skills. In cases of simple geometry there are handy, secure and cost effective procedures such as using polymerized Methylmethacrylate or titanium mesh. However, for large defects computer aided design (CAD) is gaining acceptance in the creation of custom-made cranial implants. So, the aim of this study is to report the effectiveness and safety of using preoperatively fabricated CAD implants for the reconstruction of large defects of the cranio-orbital region combined with simultaneous bone tumor excision in patients with spheno-orbital meningiomas.

Methods: Four patients, who had large spheno-orbital meningiomas involving bone of the anterior cranial base, the orbit and the sphenoid wing underwent simultaneous bony excision and reconstruction with preoperatively fabricated alloplastic implants. After implantation of 3 mini-screws for registration, a 3D computed tomography (CT) scan was initially obtained in which the predicted amount of bone excision was defined. This defect was then used to create a ceramic implant (Bioverit®, Fa. 3di) for reconstruction. At the time of surgery, the size of bone removal was first transferred into the skull using a newly authorized software with the possibility of integrating preoperatively planned resection margins into the navigation system (Navibase®, Fa. Robodent). The contour of the resection area was drawn on the skull by tracing the resection margins from the navigation screen with a pointer. Furthermore, navigated drilling was performed for optimal matching between bone defect and the implant. The implants were fixed with screws and plates.

Results: All operations were performed successfully. The preoperative planning, the transmission of the resection contours to the skull and the performance of the exact bone removal were completed without any difficulty. The postoperative course was without procedure related complications. In one case, a subcutaneous CSF leakage was observed, which healed spontaneously. In all cases, excellent contours were maintained and all patients have remained infection-free.

Conclusions: In the management of large tumors of the cranio-orbital region, simultaneous reconstruction with custom-made ceramic implants can be performed. The implants can be fabricated preoperatively based on the exact definition of the resection area using 3D CT data. During the operation precise transferring of the planned resection margins to the skull for optimal fit of the implant can be performed using navigation.