Correlations between posterior longitudinal injury and parameters of vertebral body damage.
BACKGROUND
The posterior longitudinal ligament (PLL) is an important structure of spinal stability. The loss of vertebral body height, local kyphosis (LK), and canal compromise may lead to spinal instability. This study determined the correlations between injury of the PLL and the loss of vertebrae height, kyphosis, and canal compromise.


MATERIALS AND METHODS
A retrospective review of a thoracolumbar burst fracture database was conducted from January 2009 to December 2011. Patients were divided into an intact group and a disrupted group according to the status of the PLL. The loss of vertebral height, mid-sagittal canal diameter, and LK was measured. The anterior, middle, and posterior vertebral compression ratios (AVBCR, MVBCR, and PVBCR) and mid-sagittal diameter compression ratio (MSDCR) were calculated.


RESULTS
Forty-seven patients were included in the study, including 25 patients in the intact group and 22 patients in the disrupted group. There were significant differences in the AVBCR (t = -3.048, P = 0.004), MVBCR (t = -2.301, P = 0.048), PVBCR (t = -2.116, P = 0.040), and MSDCR (t = -4.095, P = 0.000) but no difference in the LK (t = 0.408, P = 0.686) between the two groups. There was a positive correlation between the injury of the PLL and the MSDCR (r = 0.428, P < 0.01), AVBCR (r = 0.372, P < 0.01), and PVBCR (r = 0.271, P < 0.05). There was no correlation between the injury of the PLL and the LK and MVBCR.


CONCLUSIONS
The MVBCR and LK are not predictive of a PLL injury. The MSDCR, AVBCR, and PVBCR were associated with a PLL injury.
['Tan|Junming|J|', 'Shen|Lianbing|L|', 'Fang|Liangqin|L|', 'Chen|Dechun|D|', 'Xing|Shunming|S|', 'Shi|Guohua|G|', 'He|Xiang|X|', 'Wang|Jinxin|J|', 'Zhang|Jiefeng|J|', 'Liao|Teng|T|', 'Su|Jiaxiang|J|']
D000328:Adult D005260:Female D006801:Humans D017846:Longitudinal Ligaments D008159:Lumbar Vertebrae D008279:Magnetic Resonance Imaging D008297:Male D012189:Retrospective Studies D013124:Spinal Injuries D013904:Thoracic Vertebrae
Posterior longitudinal ligament Kyphosis Canal compromise Thoracolumbar burst fractures Vertebral height