A firm connection of the bone-implant-fixation system is of utmost importance for patients with cranial defects. In order to improve the connection reliability, the current research focuses on finding the optimal fixation method, as well as selection of the implant manufacturing methods and the used materials. For the latter, implementation of bioactive materials such as hydroxyapatite or other calcium phosphates has also been considered in the literature. The aim of this study was to investigate the effect of gradual osseointegration on the biomechanical performance of cranial Ti6Al4V implants with a deposited HA coating as the osseointegration agent. This effect was assessed by two different computational approaches using finite element method (FEM) modeling. The values of key input parameters necessary for FEM were obtained from experimental plasma spray deposition of HA layers onto Ti6Al4V samples. Immediately upon implantation, the HA layer at the bone-implant contact area brought only a slight decrease in the values of von Mises stress in the implant and the micro-screws when compared to a non-coated counterpart; importantly, this was without any negative trade-off in other important characteristics. The major benefit of the HA coatings was manifested upon the modeled osseointegration: the results of both approaches confirmed a significant reduction of investigated parameters such as the total implant displacements (reduced from 0.050 mm to 0.012 mm and 0.002 mm while using Approach I and II, respectively) and stresses (reduced from 52 MPa to 10 MPa and 1 MPa) in the implanted components in comparison to non-coated variant. This is a very promising result for potential use of thermally sprayed HA coatings for cranial implants.

• MeSH
• Finite Element Analysis MeSH
• Coated Materials, Biocompatible chemistry   pharmacology   MeSH
• Calcium Phosphates chemistry   pharmacology   MeSH
• Durapatite chemistry   pharmacology   MeSH
• Bone Substitutes chemistry   pharmacology   MeSH
• Skull diagnostic imaging   drug effects   pathology   MeSH
• Humans MeSH
• Osseointegration drug effects   physiology   MeSH
• Prostheses and Implants MeSH
• Alloys chemistry   pharmacology   MeSH
• Materials Testing MeSH
• Titanium chemistry   pharmacology   MeSH
• Dental Implants * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Coated Materials, Biocompatible MeSH
• Calcium Phosphates MeSH
• Durapatite MeSH
• Bone Substitutes MeSH
• Alloys MeSH
• Titanium MeSH
• titanium alloy (TiAl6V4) MeSH Browser
• Dental Implants * MeSH

In this study 6 pre-operative designs for PMMA based reconstructions of cranial defects were evaluated for their mechanical robustness using finite element modeling. Clinical experience and engineering principles were employed to create multiple plan options, which were subsequently computationally analyzed for mechanically relevant parameters under 50N loads: stress, strain and deformation in various components of the assembly. The factors assessed were: defect size, location and shape. The major variable in the cranioplasty assembly design was the arrangement of the fixation plates. An additional study variable introduced was the location of the 50N load within the implant area. It was found that in smaller defects, it was simpler to design a symmetric distribution of plates and under limited variability in load location it was possible to design an optimal for expected loads. However, for very large defects with complex shapes, the variability in the load locations introduces complications to the intuitive design of the optimal assembly. The study shows that it can be beneficial to incorporate multi design computational analyses to decide upon the most optimal plan for a clinical case.

• MeSH
• Algorithms MeSH
• Finite Element Analysis * MeSH
• Models, Anatomic MeSH
• Bone Plates MeSH
• Skull diagnostic imaging   injuries   surgery   MeSH
• Humans MeSH
• Stress, Mechanical MeSH
• Tomography, X-Ray Computed MeSH
• Polymethyl Methacrylate chemistry   MeSH
• Preoperative Period MeSH
• Titanium chemistry   MeSH
• Plastic Surgery Procedures instrumentation   methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Names of Substances
• Polymethyl Methacrylate MeSH
• Titanium MeSH