Problem

The design of femoral hip prostheses crucially impacts patients' recovery and hip functionality, especially for those who have experienced fractures or diseases. Even slight changes in shape or size can determine the body's acceptance or potential dislocation, leading to further surgical interventions. The challenge lies in identifying ideal shapes, sizes, and materials that minimize stress shielding and improve prosthetic integration within the femur. Historically, this issue has driven extensive research in orthopaedics, prompting the exploration of innovative designs and materials to optimize patient outcomes.

Solution

A research project was conducted to investigate the relationship between materials and geometries of hip prostheses with their effects on stress shielding. Stress distribution patterns were analysed through Solidworks simulations and finite element analysis (FEA), and factors contributing to stress shielding phenomena were identified. The goal was to optimize material selection and geometric design in order to minimize stress shielding and improve the long-term performance of hip implants in patients.

Through comprehensive research and modelling, various materials like 316L Stainless steel, Alumina, and Carbon PEEK were evaluated. The results demonstrated that Alumina, a ceramic material, provided optimal stress distribution in the femur, making it an excellent choice for hip prostheses. Its successful integration not only minimized stress shielding but also ensured patients can regain regular hip function, avoiding the need for revision surgeries. This finding emphasizes the significance of innovative materials like Alumina in enhancing the effectiveness and longevity of hip replacement surgeries, benefiting patients' overall quality of life.

Implementation

An accurate model of a hip prosthesis was created using Solidworks. This model was then fitted into an existing human femur model, and boundaries were set to replicate human-like conditions, including the load analysis and fixed geometries. To enhance the accuracy of the experiment, a mesh convergence analysis was conducted, computationally determining the ideal mesh sizes. This method allowed for precise measurements of stresses and strains in both the x and y directions, providing crucial data for evaluating the prosthetic's performance under various conditions.

Impact and Benefits

Improved long-term performance of hip implants by minimizing stress shielding
Reduced complications such as implant loosening, bone resorption, and implant failure
Informed material selection and geometric design for hip prostheses to improve patient outcomes

Skills Developed

Solidworks
Finite Element Analysis
Biomedical Engineering

Optimizing Hip Prostheses Material & Geometry