Study design: A prospective, consecutive case series.
Objective: To evaluate which variable has a strong association with neurological damage in thoracolumbar burst fractures (T12 or L1): severity of injury or narrowing of the spinal canal.
Setting: Department of Spine Surgery, the Affiliated Hospital, Luzhou Medical College, Sichuan Province, China.
Methods: This study included 42 patients with thoracolumbar junction burst fractures (T12 or L1), 24 patients with neurological deficit, and 18 patients without deficit. The severity of injury was determined using the Injury Severity Score (ISS) and the New Injury Severity Score (NISS), and the narrowing of the spinal canal was measured by axial computed tomography. The statistical comparison of the neurological deficit and the non-neurological deficit was carried out using nonparametric tests (Mann-Whitney test). The correlation of these scores and narrowing of the spinal canal to the neurological status was determined using a Spearman correlation test.
Result: Higher ISS (21 vs. 11), NISS (30 vs. 15), Injury Severity Score with modification (ISSM) (13 vs. 11), New Injury Severity Score with modification (NISSM) (21 vs. 15), and canal compromise (48 vs. 25) were found in patients with neurological deficit, which evidently yielded statistical differences between the patients with neurological deficit and those without (P<0.01), and they also had a positive correlation with the American Spine Injury Association (ASIA) score (r>0.5, P<0.001). Moreover, there was also a positive correlation (r=0.375, P<0.05) between ISSM and ASIA scores, although it seemed weak. The correlations between the NISS, NISSM, and neurological deficit (respectively r=0.868, P<0.001; r=0.676, P<0.001) were stronger than with the narrowing of the spinal canal (r=0.560, P<0.001).
Conclusions: NISS have a closer correlation with neurological deficit in thoracolumbar burst fractures; thus, we can put forward a hypothesis that perhaps NISS is able to reflect the dynamic fracture process.