Adaptive Mechanism for Designing a Personalized Cranial Implant and Its 3D Printing Using PEEK

Abstract

The rehabilitation of the skull’s bones is a difficult process that poses a challenge to the surgical team. Due to the range of design methods and the availability of materials, the main concerns are the implant design and material selection. Mirror-image reconstruction is one of the widely used implant reconstruction techniques, but it is not a feasible option in asymmetrical regions. The ideal design approach and material should result in an implant outcome that is compact, easy to fit, resilient, and provides the perfect aesthetic and functional outcomes irrespective of the location. The design technique for the making of the personalized implant must be easy to use and independent of the defect’s position on the skull. As a result, this article proposes a hybrid system that incorporates computer tomography acquisition, an adaptive design (or modeling) scheme, computational analysis, and accuracy assessment. The newly developed hybrid approach aims to obtain ideal cranial implants that are unique to each patient and defect. Polyetheretherketone (PEEK) is chosen to fabricate the implant because it is a viable alternative to titanium implants for personalized implants, and because it is simpler to use, lighter, and sturdy enough to shield the brain. The aesthetic result or the fitting accuracy is adequate, with a maximum deviation of 0.59 mm in the outside direction. The results of the biomechanical analysis demonstrate that the maximum Von Mises stress (8.15 MPa), Von Mises strain (0.002), and deformation (0.18 mm) are all extremely low, and the factor of safety is reasonably high, highlighting the implant’s load resistance potential and safety under high loading. Moreover, the time it takes to develop an implant model for any cranial defect using the proposed modeling scheme is very fast, at around one hour. This study illustrates that the utilized 3D reconstruction method and PEEK material would minimize time-consuming alterations while also improving the implant’s fit, stability, and strength.

Optimizing cranial implant and fixture design using different materials in cranioplasty

“…A static load of 50N on a PEEK cranial implant with Titanium micro screws only attached at symmetrical locations across the implant-skull interface showed that von Mises stresses within the PEEK implant peaked at 8.15MPa. 26 In our study, a PEEK implant with Ti-6Al-4V fixation systems remained within range of 0.0166MPa to 0.0174MPa. This significant reduction of stress in the implant could be predominantly due to a larger surface area of the fixation plates which concentrates critical stresses away from the implant towards the plate.…”

Low-Cost Cranioplasty—A Systematic Review of 3D Printing in Medicine

“…Meta-analyses performed by Punchak et al and van de Vijfeijken proved that surgeries performed with the use of PEEK carry lower risks of infection than PMMA and autologous bone cranioplasties [ 106 , 191 ]. In a study performed by Mian et al, 3D-printed PEEK implants delivered great precision, minimal deviation (0.5919 mm), with maximal von Mises stress (8.15 MPa), von Mises strain (0.002) and minimal deformation (0.18 mm), which underlines the implant’s extraordinary load-bearing capability [ 192 ]. Similar observations have been made in a preclinical study designed by Sharma et al [ 193 ].…”

Customized Barrier Membrane (Titanium Alloy, Poly Ether-Ether Ketone and Unsintered Hydroxyapatite/Poly-l-Lactide) for Guided Bone Regeneration

“…Modern 3D computer-assisted surgery (3D CAS), which combines 3D printing technology with 3D imaging techniques, has undergone remarkable developments in the past decades. As shown in Figure 2 , several protocols are essential to 3D CAS: 1) information acquisition, 2) planning, 3) virtual operation, 4) 3D printing, and 5) surgery and postoperative analysis ( Troulis et al, 2002 ; Prevost et al, 2019 ; Mian et al, 2022 ). Although potential errors occur in the fabrication of customized barrier membranes after tomography data acquisition, image processing, and 3D fabrication ( Tian et al, 2021 ), technological developments in rapid prototyping systems have considerably contributed to the accurate and detailed replication of craniofacial devices ( Sharma et al, 2021 ).…”