Finite element analysis of a hybrid corrugated hip implant for stability and loading during gait phases

Expansion limits of meshed split-thickness skin grafts

Split-thickness skin grafts are widely used to treat chronic wounds. Procedure design requires surgeons to predict how much a patch of the patient's own skin expands when it is meshed with rows of slits and stretched over a larger wound area. Accurate prediction of graft expansion remains a challenge, with current models overestimating the actual expansion, leading to suboptimal outcomes. Inspired by the principles of mechanical metamaterials, we developed a model that distinguishes between the kinematic rearrangement of structural elements and their stretching, providing a more accurate prediction of skin graft expansion. Our model was validated against extensive data from skin graft surgeries, demonstrating vastly superior predictive capability compared to existing methods. This metamaterial-inspired approach enables informed decision-making for potentially improving healing outcomes. STATEMENT OF SIGNIFICANCE: Accurately predicting the expansion of meshed skin grafts is crucial for minimizing patient trauma and optimizing healing outcomes in reconstructive surgery. However, current quantitative models, which treat grafts as tessellated trusses of rigid bars, fail to accurately estimate graft expansion. We have uncovered the mechanisms underlying skin graft expansion and developed a straightforward method based on these findings. This method, designed for practical use by surgeons, provides accurate predictions of graft expansion, as validated against extensive data from skin graft surgeries.

Development of patient-specific finite element model for study of composite dental implants

Traumatic dental injuries can occur due to various reasons such as accidents, sports injuries, fights, falls, and others. These injuries can affect the teeth, gums, and surrounding tissues, and can range from minor chips and cracks to severe fractures, dislocations, and avulsions (when the tooth is completely knocked out of the socket). The most common way to address this is by replacing affected teeth with dental implants. The purpose of this research is to evaluate the use of composite materials in dental implants and compare them with the traditionally used materials using a patient specific cone beam computed tomography (CBCT) based finite element model (FEM). To conduct this research, two different implant groups i.e., traditional implant and composite implant were designed using Titanium grade 4, zirconium oxide-reinforced lithium silicate (ZLS), and Zirconia (ZrO2). Six dental implants were designed namely Ti implant, ZLS implant, ZrO2implant, Ti-ZrO2composite, Ti-ZLS composite, and ZLS-ZrO2composite using 3D modelling software. Detailed full-scale 3D models of patient specific dental implant were developed and traumatic loading conditions were applied to the enamel of central incisor teeth or crown of dental implant, and maxilla was constrained in all directions. It was found that the use of composite materials for dental implants can reduce the stresses over the surface of abutment and implant as compared to traditional implants. The detailed models developed as a part of this study can advance the research on dental implants, and with further experimental validation allow the use of composite materials for fabrication of more stable dental implants.