Session: DAC-15-02-Multidisciplinary Design Optimization, Multiobjective Optimization, and Sensitivity Analysis

Paper Number: 89854

89854 - Design Optimization of Pelvic Prosthesis for Type-1 Resection 

Reconstruction of the pelvic region post the resection of pelvic bone sarcoma is vital for the rehabilitation and restoration of activities of daily living in patients. The prosthesis design should restore maximum functional outcomes for tumors that do not significantly decrease life expectancy. Currently, reconstruction methods use either bone grafts or prostheses. For tumors at regions such as the iliac wing and for young patients, there is minimal chance of bone grafts to remodel into the exact anatomy of the iliac wing. On the other hand, a customized pelvic prosthesis ensures restoration of the anatomical configuration and mechanical strength. A commercially available pelvic prosthesis is solid and is much stiffer than the bone leading to stress shielding effect and higher strains on the intact pelvic bone. This work proposes the design of a lightweight Ti$_6$Al$_4$V pelvic prosthesis for type-I resection due to a sarcoma at the iliac wing, which matches the exact anatomy of the pelvic bone. First, a compliance minimization problem subject to gait cycle loads with mass constraint equal to the mass of the resected iliac bone is solved using topology optimization. Then the density field from topology optimization is mapped into shell and lattice infills. Prosthesis designs with different lattice structures are subjected to a compression test simulation, and prosthesis with the stiffest structure is identified. Thus, a lightweight prosthesis, similar in geometry, stiffness and mass to the natural iliac bone, is achieved with a decrease in stress shielding effect.

Presenting Author: Rajaraman S Indian Institute of Technology Madras

Presenting Author Biography: Research student in the department of mechanical engineering, IIT Madras, Chennai, India. Interested in multidisciplinary optimization and dynamics of structures and mechanisms.

Authors:

Rajaraman S Indian Institute of Technology Madras
Sourav Rakshit Indian Institute of Technology Madras