Bradley Elmer

Graduation Semester and Year




Document Type


Degree Name

Master of Science in Biomedical Engineering



First Advisor

Mario Romero-Ortega


Correction forces during spine deformity surgery impart significant multidirectional stress forces to the spinal cord, which in some cases result in severe damage to the spinal cord and permanent paralysis, the most feared complication. Animal models are critical for the development of neuroprotective strategies. However, those currently available are limited to contusion, transection, or unidirectional distraction injuries, which fail to replicate the multidirectional forces that occur during spine corrective surgery. In order to develop an improved model of distraction spinal cord injury we designed a device based on intervertebral grip fixation and linear actuators, capable of inducing controllable bidirectional distraction injury to the spine. The device was tested using a 7mm distention paradigm of the rat T10-12 vertebra. Twenty-four hours after injury, all animals showed a drastic drop in the Basso, Beattie and Bresnahan (BBB) locomotor scale, from a normal 21 level to that of complete hind limb paralysis (0.17 +/- 0.41). The severity of this injury was confirmed by gross evaluation and histology using glial fibrillary acidic protein immunocytochemistry for visualization of reactive gliosis. The high precision, control, and reproducibility of this bidirectional spine distraction device would contribute to the testing of neuroprotective strategies aimed at preventing unintended new neurological damage during corrective spine surgery.


Biomedical Engineering and Bioengineering | Engineering


Degree granted by The University of Texas at Arlington