Imaging-based customization of lattice structures for biomedical applications

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Synovial joints can provide movement and articulation, however, with overuse, aging, and trauma, joint replacement surgeries may be needed. Commercially available joint reconstruction implants have undergone great improvement during the past decades. Nevertheless, existing solutions using available implant designs and materials have limitations that lead to potential failure, particularly with young active patients. Bone cement and stress shielding have been identified as the major reasons for premature artificial joint failures. A breakdown of the cement may happen and revision surgery may be needed because of the aseptic loosening. The stress shielding problem is caused by the significant mismatch of stiffness properties between the patient trabecular bones and metallic implant materials for joint replacement surgeries. This research introduces a novel method to develop customized lattice structures with graded properties according to the mechanical properties derived from clinical Computed Tomography (CT) scan of the bone. Various lattice design variables are being analyzed for their effects on mechanical performance and geometrical features needed for biological fixation and manufacturability. The introduced mathematical models and techniques in the proposed work facilitate generic direct digital design and manufacturing of effective customized lattice structures with graded properties for joint reconstruction applications.