Objective      To determine the effect of midsagittal canal compromise correlation and rotation angle of bone fragments on the reposition of bone fragment after thoracolumbar burst fracture. Methods     A retrospective analysis was carried out on 62 patients with single thoracolumbar burst fracture admitted in our department from 2010 to 2014. According to the results of C-arm X-ray system during the operation

the patients were divided into the reposition group (n=34) and non-reposition (n=28). The fractures were classified according to AO classification. Neurological status was evaluated according to the ASIA grade. The rotation angle of bone fragment and calculates the mid-sagittal canal compression ratio were analyzed. Results        There were significant differences in the mid-sagittal canal compression ratio between the reposition group and the non-reposition [(18.1±11.3)% vs (59.8±20.6)%

t=9.581

P0.01]

and in the rotation angles of bone fragments [(38.1±18.7)° vs (21.7±11.6)°

t=4.041

P0.01]. Logistic regression analysis indicated that AO classification (Wald=6.415

P0.05) and midsagittal canal compression ratio (Wald=5.417

P0.05) were correlated with the reposition of bone fragments

while ASIA grade (Wald=3.816

P0.05) had no such correlation. Conclusions    AO classification and mid-sagittal canal compression ratio are predictors of assessing the reposition of bone fragments in the thoracolumbar fractures.