Laminar fractures as a severity marker in burst fractures of the thoracolumbar spine.

PURPOSE To assess the correlation between the presence of lamina fractures, narrowing of the spinal canal, and the severity of injury. METHODS Records of 146 men and 44 women aged 13 to 84 (mean, 39) years diagnosed with burst fractures of the thoracolumbar spine were retrospectively reviewed. The laminar fractures and narrowing of the spinal canal were measured using computed tomography. The severity of injury was determined using the Injury Severity Score (ISS) and the New Injury Severity Score (NISS). The ISS and NISS of patients with and without laminar fractures were compared. The sensitivity and specificity of ISS, NISS, and narrowing of the spinal canal in association with laminar fractures were also compared. RESULTS 92 (48%) of the patients had laminar fractures. The mean narrowing of the spinal canal was more severe in patients with laminar fractures than those without (47% vs 28%, p<0.001). Patients with laminar fractures had a significantly higher mean ISS (17 vs 12, p<0.001) and NISS (19 vs 13, p<0.001). Narrowing of the spinal canal is more sensitive and specific than the ISS and NISS when correlating laminar fractures. CONCLUSION In patients with burst fractures of the thoracolumbar spine, the presence of laminar fractures indicates a more severe injury.