Evaluation of locally manufactured patient-specific custom made implants for cranial defects using a silicone mould

Abstract

Background: Cranial vault defects can pose a significant problem for neurosurgeons where autologous bone is no longer available for cranioplasty. Numerous materials exist to create implants which include polymethyl methacrylate (PMMA) and titanium. A technique using 3-dimensional CT scan reconstruction of a cranial defect and creating a silicon mould which can be autoclaved in theatre to create a PMMA implant was developed. Objectives: The aim of this study is to evaluate the efficacy, cosmetic result, safety and cost-effectiveness of this procedure and compare this to existing techniques. Methods: An ambispective study was performed in patients requiring cranioplasty with a custom made implant. Patients were assessed for risk factors and cosmetic outcome, surgical technique was described and complications and cost compared to existing literature between 2010 and 2016. Results: Thirty retrospective and 30 consecutive prospective patients were recruited into the study. Overall sepsis rate was 8.3%. All septic cases had superficial sepsis of which 2 grafts were removed due to cerebrospinal fluid leakage resulting in wound breakdown. A 100% accurate implant to defect ratio was achieved leading to a high satisfaction rate. Average cost was 5 times cheaper than the closest market related product. Conclusion: Patient specific moulds using PMMA to create custom implants are safe, have excellent cosmetic results and are a very cost-effective option to manage cranial defects. Accurate planning strategies for large craniotomies, where bone will potentially be discarded, add to surgical effectiveness and cost-saving to the patient.S Afr J Surg 2018;56 (3) http://dx.

Accuracy Assessment of Molded, Patient-Specific Polymethylmethacrylate Craniofacial Implants Compared to Their 3D Printed Originals

“…If this step takes too long, the cement will begin to harden and cannot be molded accordingly. Consequently, the implant can become too thick, or the fine structures in the border areas cannot be reached by the material, resulting in an insufficient fit [33]. This can also be caused by pressure-dependent displacement of the silicone mold during PSI fabrication [12,34].…”

PMMA Cranioplasty Making by Using Open Source CAD Softwares, PLA Printers and Silicone Rubber Molds: Technical Note with 2 Illustrative Cases

“…margins) during unmolding, which provided good stabilization and there was no need for rigid fixation [13]. One of the other advantages of the silicon mold is the ability to re-use it if necessary as the mold is simply resterilised in theatre and a new PMMA implant created [14]. In our study, we demonstrated the safety and practicality of making cranial implants by using open source CAD softwares, a PLA 3D printer, PMMA, and autoclavable laboratory silicone.…”

PMMA Cranioplasty Making by Using Оpen-Source CAD Software, PLA Printers, and Silicone Rubber Molds: Technical Note with Two Illustrative Cases

“… 14 One of the other advantages of the silicon mold is the ability to reuse it if necessary as the mold is simply resterilized in theater and a new PMMA implant created. 15 In our study, we demonstrated the safety and practicality of making cranial implants by using open-source CAD software, a PLA 3D printer, PMMA, and autoclavable laboratory silicone. The implant created matched to the craniectomy defect perfectly.…”