Abstract
Introduction
Different types of spinal cord injury models in rats were described in the literature, including spinal cord clip compression. This type of procedure can be performed by placing the clip in two directions in relation to the spinal cord: lateral or posterior. Studies published in the literature usually do not describe the direction of the clip placement. It is assumed that the severity of neurological symptoms and the histological lesion are different from each other in these two models. The objective is to evaluate the locomotor and the histological impact on the spinal cord comparing lateral and posterior clip placement.
Materials and Methods
This study is a randomized experimental trial. A total of 20 female Wistar rats, ranging from 250 to 300 g, aged 12 to 14 weeks, were randomized in two groups by the direction of clip placement: lateral group (n = 10) and posterior group (n = 10). After exposing the thoracic segment of spine (T8–T10), a laminectomy was performed at the T9 level under microscope view. The spinal cord injury was made using a 5 mm long aneurismal clip with a closing pressure of 50 g. Locomotor behavior was evaluated by the Basso, Beattie, and Bresnahan scale at the 1st, 7th, 14th, 21st, and 28th day after surgery and the histological analysis of the injury area by computer software.
Results
The histological evaluation showed a greater lesion area in the lateral group, mean 2.3 ± 2 mm2, when compared with the posterior group, mean 4.8 ± 1 mm2 (p = 0.03). There was no overall difference between lateral and posterior locomotor scores from day 1 to 28 (p = 0.361).
Conclusion
The lesion area observed in the spinal cord histology after the lateral placement of a clip was significantly greater than in the posterior direction of the clip. There was no overall motor performance difference between lateral and posterior BBB scores.