The Design Of Dynamic Pedicle Fixation And The Experimental Studies On The Treatment Of Thoracolumbar Burst Fractures

Part 1. The long-term results of thoracolumbar burst fractures treated with short-segment pedicle screw systemObjective: To analyze the long-term results of thoracolumbar burst fractures treated with short-segment pedicle screw system(SPSS). Methods: Ninty-two cases of thoracolumbar burst fractures were treated with SPSS from 1994 to 2000,and 64 cases of them were followed-up successfully 5-11 years(average 7.3 years). All of them were checked with radiography pre- and post operation, before implant removal and the final follow-up assessment. The anterior and posterior height of the fractured vertebral bodies, the adjacent disc spaces and the Cobb angles were measured. Thirteen cases were checked with magnetic resonance imaging at the final follow-up assessment. Results: 1, The clinical results, such as the neurological function and the remnants of low back pain were satisfactory.2,Of the 64 cases,pedicle screws broke in 3cases,and rods broke in 1 case.3,The height of the vertebral bodies and the adjacent disc spaces were improved evidently, and last to the time point before implant removal, but dropped obviously at the final follow-up assessment, especially at the cranial disc spaces.4, Fractures of the cranial endplates were not restored absolutely, so the morphology of the injuried discs changed irregular in MRI, and the adjacent discs degenerated in MRI. Conclusion: The long-term results of SPSS for thoracolumbar burst fractures are satisfactory. Dropping in the height of the vertebral bodies and the adjacent disc spaces lead to the implants breakage and the correction loss. The important causes of the disc spaces narrowing are the degeneration and no restoration morphology of the injuried discs.