Imageologic analysis of thoracolumbar burst fracture of Denis type B

Abstract

Objective To investigate the roles of pedicle fracture and vertebral compression in thoracolumbar burst fractures of Denis type B. Methods A total of 211 patients with burst fracture of Denis type B were reviewed who had been treated at our department from September 2007 to May 2014. They were analyzed in terms of age, gender, diagnosis, fractured segmental level, ASIA (American Spinal Injury Association) grade of spinal cord injury, and preoperative imaging data (spinal CT and anteroposterior and lateral X-ray films). The associations of pedicle fracture (intact pedicle, unilateral and bilateral pedicle fractures) and vertebral compression (≤1/2 versus>1/2) with age, gender, fractured segmental level and ASIA grade were analyzed statistically. Results Of all the 215 fractured segments of Denis type B, 134 had intact pedicle (62.3% ), 60 unilateral pedicle fracture (27.9% ), and 21 bilateral pedicle fracture (9.8% ). 156 segments (72.6% ) had ≤1/2 vertebral compression and 59>1/2 compression (27.4% ). The incidence of pedicle fracture was 18.9% in cases of ≤1/2 vertebral compression and 36.4% in cases of>1/2 compression. Age, gender, and fractured segmental level had no significant effects on either pedicle fracture or vertebral compression (P>0.05). ASIA grade had a significant effect on pedicle fracture (P=0.020) and there was a linear association between ASIA grade and pedicle fracture (χ2=12.190, P=0.000; Spearman rank correlation coefficient=0.187, P=0.006). ASIA grade had no significant effect on vertebral compression (χ2=3.523, P=0.318). ASIA grade had a significant effect on pedicle fracture combined with vertebral compression (χ2=0.422, P=0.001). Conclusions Gender, age and fractured segmental level may have an insignificant impact on pedicle fracture or vertebral compression. The greater a vertebral compression, the more serious a pedicle fracture. The more serious a pedicle fracture, the more severe a spinal cord injury. Key words: Thoracic vertebrae; Lumber vertebrae; Fractures, bone