Additively Manufactured Patient Specific Cranioplasty Implants with Antibacterial Properties

Cranioplasty is a common technique for repairing bone defects in the cranium arising from cranial bone deformities, traumatic skull bone fracture, bone cancer and infections. Poly-methyl-methacrylate (PMMA) is the biomaterial that has been most widely adopted for cranioplasty as it showed better long-term outcomes. Cranioplasty procedure is usually performed through in situ forming approach where the reagents are mixed to initiate the radical polymerization of PMMA and used directly to repair the skull. Although this procedure is considered convenient as it reduces the time from diagnosis to implantation but the heat and shrinkage due to the polymerization process as well as the release of unreacted monomers represent the main drawbacks. In addition, infection has complicated the outcome of cranial repair with significant additional morbidity. Studies has shown a rate of graft infection higher than 10% in surgical PMMA cranioplasty. Additive manufacturing, also known as three-dimensional (3D) printing, can be used for producing detailed geometries based on individual and particular demands at lower cost. Some applications of the 3D printing are related to the production of personalized devices, implants, drug dosage forms or 3D implants that contain active pharmaceutical treatments. This study aimed to produce a modified PMMA with antibacterial properties for additive manufacturing of patient specific cranioplasty implants. The additive manufacturing of the cranioplasty implants could address the drawbacks from currently used in-situ forming approach while the grafted antibacterial agent could reduce the cranioplasty related infections.