The morphological measurement and clinical significance of thoracic and lumbar vertebral posterior wall in patients with osteoporotic vertebral fracture

English Keywords:Osteoporotic vertebral fracture  Vertebral posterior wall morphology  Percutaneous kyphoplasty  Bone cement leakage  CT 3D reconstruction

English Abstract:

  【Abstract】 Objectives: To investigate the difference of thoracic and lumbar vertebral posterior wall morphology in patients with osteoporotic vertebral fracture and its clinical significance. Methods: 98 patients with complete detailed data were enrolled in this study from January 2013 to December 2016, the related parameters of the T6-L5 vertebral were observed and measured through the CT 3D reconstruction and multiplanar reconstruction(MPR). Inclusion criteria were without fresh or old fracture of vertebral body, without infection, tumor, hemivertebral body and obstructive vertebral deformity. Exclusion criteria were the vertebral bodies that had been treated with percutaneous kyphoplasty(PKP). The following parameters were measured and analyzed by using CT image from T6 to L5: (1)AB, the distance between the junctions of the posterior border of bilateral vertebral body and the medial cortical at the axial plane of vertebral arch; (2)OC, the distance between line AB and point O(the top point of spinal canal intruded into the relative vertebral body); (3)PC, the distance between line AB and the top point of anterior edge of body; (4)R=OC/PC was calculated(in the C arm fluoroscopy lateral imaging, the ratio of the lumbar of vertebral disc to the sagittal diameter of vertebral body). To compare the OC values of T12 and L1 through independent sample t test. Results: The range of PC values from T6 to L5 was from 23.42±0.21mm to 44.38±4.51mm, the OC value from T6 to T12 was from 3.83±0.13mm to 5.21±0.06mm, the data from two groups were gradually increasing. The OC value from T12 to L5 was from 5.21±0.06mm to 0mm, which was gradually decreasing. The R value from T6 to T12 was close to 0.16(1/6), compared with thoracic vertebra, the lumbar vertebra decreased significantly, which was significantly less than 1/6 in L1 to L3, and was close to 0 in L4 and L5. The difference between the OC values of T12 and L1 was statistically significant(P<0.05). Conclusions: The posterior wall morphology of thoracic vertebral body is significantly different from that of lumbar vertebra, and the OC structure causes the posterior wall of the middle and lower thoracic vertebral body to be located in the posterior of the vertebral body 1/6. Due to the presence of OC structure in the middle and lower thoracic vertebra, it is possible to reduce the occurence of bone cement leakage into spinal canal through avoiding bone cement distribution over the posterior 1/6 of vertebral body in PKP.