Research Projects

The problem of osteoporosis is becoming a global concern as well as in India, particularly in the elderly and diabetic populations. These patients suffer from a porous bone structure, leading to a reduction in bone strength. This condition leads to bone fracture, particularly in the high load-bearing joints such as the hip (femoral neck fracture leading to loss of mobility) and patients undergo Total Hip Replacement (THR) surgery. The commercially available THR (made of fully solid) are designed based on healthy bone without considering the effect of osteoporotic bone. This leads to a stiffness mismatch between the implant and the bone and in turn leads to issues such as poor load transfer, stress shielding, and aseptic loosening, thereby causing premature implant failure. Lattice-structured implants offer a promising alternative. These structures can be optimized to reduce stress shielding and corresponding bone density loss. Furthermore, incorporating patient-specific CT data enables implants to be tailored not only in external shape but also in internal mechanical behaviour, making them suitable for individuals with varying bone density. This proposal aims to design, develop, and validate the TPMS lattice-structured cemented hip implants for the different osteoporotic bone conditions. This proposal addresses the gap by suggesting a solution for the development of cemented hip implants for osteoporotic bone. To mimic the properties of the bone, TPMS lattice structures will be utilized within implants to reduce the overall stiffness of the implant. In this proposal, 3 types of TPMS lattice structures will be considered (Diamond, Gyroid and Primitive), in order to understand the suitability of appropriate lattice structures for different osteoporotic conditions. Detailed mechanical and biomechanical analysis will be performed by utilizing both numerical and experimental methods. The implants will be manufactured using laser powder bed fusion (LPBF), a metal 3D printing technique, and will be tested according to proper standard for mechanical and biomechanical properties, microstructural characterization, biomechanical testing and validation for possible clinical translations. First detailed numerical analysis will be performed to identify the effective elastic modulus of three different TPMS lattice structures with varying porosity. 3D printing of the designed lattice structures will be done using the LPBF technique and Ti6Al4V powder material. Mechanical testing of the lattices will be performed according to ASTM standard to validate numerically predicted elastic modulus and to identify strength. Thereafter, design and biomechanical analysis of TPMS lattice-structured femoral implants will be performed for different osteoporotic conditions using CT datasets. A series of iterative processes will be performed to identify the appropriate design parameters for cemented femoral implants for different osteoporosis conditions. Then, optimized lattice-structured implants will be 3D printed using the LPBF AM technique. The printed implants will be mechanically tested according to ASTM standard to estimate the static and fatigue life. Finally, the biomechanical testing and validation will be performed using composite sawbones to understand the load transfer and stress or strain shielding. The proposed project is aligned with the national health priorities, where the problem of osteoporosis and diabetes is on the rise. This project will strengthen the biomedical research capabilities by fostering collaboration between biomechanical, material and manufacturing engineers (IIT Mandi) and orthopaedic surgeons (AIIMS Bilaspur). It offers good potential for indigenous implant manufacturing. This will make implants much more affordable and accessible to society. Further, the proposed plan can lead to several licensing opportunities and partnerships with the companies focused on digital orthopaedics and implant manufacturing in India.