An experimental study was conducted with the objective of evaluating the effects of compression and distraction (approach and deviation) forces applied on implants placed at vertebral pedicles. The vertebral segments T8-T9, T10-T11, T12-L1, L2-L3 and L4-L5 of Landsark pigs were used in the study. Each vertebral segment was fixed with pedicular implants, with compression or distraction forces being applied with a displacement that ranged from 5.1 mm to 9.35 mm. Displacement caused by forces application was measured in four points of the vertebral segment: A (anterior portion of the vertebral segment), B (medial portion of the vertebral segment), C (posterior portion of the vertebral segment) and D (superior joint process). Compression forces caused the deviation of points located at regions A and B, and the approach of points at region D. Distraction forces caused the approach of points at regions A and B and deviation of the points at region D.
Spine fusion; Spine fixation
