Article ID Journal Published Year Pages File Type
876503 Medical Engineering & Physics 2009 6 Pages PDF
Abstract

Numerous studies have assessed lumbar interbody fusion, but little data from direct interbody load measurements exists. This manuscript describes an interbody fusion cage with integrated 4-axis load cell that can simulate implant heights of 13, 15, 17, 19 and 21 mm. The calibrated load cell was accurate to within 7.9% for point compressive loads over the central 8 mm × 8 mm region, but up to 26.8% for eccentric loads on the outer 16 mm × 16 mm rim of the device (although typically errors were less than half). Anterior–posterior shear and lateral shear loads did not affect compressive load measurement (<1.0% and <3.5%, respectively). Moments calculated from 4 load sensing corner pillars demonstrated errors below 2.3% in lateral bending and 2.1% in flexion-extension. Although this device does not have the accuracy of other much larger corpectomy implants, it incorporates four channels of load and simulates multiple implant heights, making for a favorable comparison in this restricted space. This device has immediate use in cadaveric testing, providing data previously not attainable, and serves as a novel technological step towards an implantable interbody device with multi-axis load sensing capability. As per the authors’ knowledge, no such device has previously been described.

Related Topics
Physical Sciences and Engineering Engineering Biomedical Engineering
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