Functional imaging reveals modest strain concentrations associated with implant micromotion using modified BAK interbody cages

• Main Author: Berry, Daniel J.
• Other Authors: Bay, Brian K.
• Language: en_US
• Published: 2012
• Subjects: Spinal fusion; Spinal implants; Strains and stresses
• Online Access: http://hdl.handle.net/1957/32259

Interbody fusion cages are increasingly used in the treatment of spinal disease and injury in order to stabilize movement and promote arthrodesis of the vertebral bodies, but the micro-mechanics of the interaction between the cage and the adjacent host bone is not fully understood. This information has bearing on post-surgical therapy protocols, prediction of long-term bone tissue changes, and optimization of cage design. In order to gain insight into this problem, functional microCT imaging was used to directly evaluate implant micromotion and full-field vertebral body strains in an animal model implemented with various configurations of BAK interbody cages. It is believed that variations in cage design will produce variable implant success, functional fusion will be related to the extent of implant fixation, and specific strain fields will be associated with fused and unfused samples. We found that samples ranged from completely unfused (implant motion) to fully fused with organized trabecular bone (no motion). Strains concentrated at the implant interface in unfused samples, while fully fused samples exhibited uniformly distributed strains. === Graduation date: 2004