Abstract
Introduction
This study is to summarize the main radiographical feature of osteoporotic vertebral fracture nonunion (VFNU) in extended CT reconstruction images, and to evaluate reducibility and stability of the vertebrae.
Patients and Methods
All of the senior patients suffered from thoracolumbar spine fracture (December 2009 to March 2013) were retrospectively reviewed, 36 cases of VFNU with 39 level of vertebrae were included in this study according to inclusion criteria. The main radiographical features of 39 level of VFNU vertebrae were analyzed, including the specific segment, the type of substance in the intravertebral cleft, the starting points and terminals of intervertebral cleft, to explore the different radiographic feature of various type of VFNU.
Results
According to the over extension CT, new classification criteria are reported in the literature, all of VFNU patients were divided into the following three subgroups: reducible type (type A), unstable but can be reset type (type B), and loss of reducibility type (type C). Overall, 39 level of VFNU vertebrae in 36 patients were located in the region of T9 to L4, in which the thoracolumbar segments were compromised frequently, and 16 level of VFNU existed in L1. According to extended CT reconstruction images, 25 level of type A, 7 level of type B, and 7 level of type C VFNU were identified with the radiographic analysis, the starting points of intervertebral cleft located in the anterior edge of vertebral body (18 levels) or disc plate (21 levels), the terminals of cleft located in the intersecting point of pedicle and posterior–inferior edge of vertebral body (18 level) or superior disc plate (14 levels), the fracture line could be displayed clearly in the all coronal CT reconstruction images, however, terminals of intravertebral cleft in type C VFNU located in the trabecular bone region in the middle one-third part of vertebral body(4 level), and the middle one-third part of superior disc plate, even though there were significant collapse or intracranial retropulsion of posterior one-third part of vertebral body, fracture line could rarely be shown except for one patient, the fracture lines lateral cortex united in three patients, or just be shown in anterior–middle part of vertebral body in three patients according to the coronal CT reconstruction images.
Conclusion
Thoracolumbar segments are the most common region compromised by VFNU. There is a difference between the terminals of intravertebral cleft of types A, B, and C VFNU, and existence of fracture lines from the anterior edge to the posterior cortex might explain the mechanism of reducibility of types A and B.