Clinical and Radiologic Features of Osteoporotic Spine Fracture with Delayed Neurologic Compromises

Abstract

Osteoporotic spine fractures (OSFs) with delayed neurologic compromises (NCs) have been increasingly reported. Although several studies have addressed that the pathologic mechanism of NC involves nonunion and segmental instability, the risk factors remain unclear. Therefore, the purpose of this study was to assess the radiologic and clinical features of OSFs with delayed NC. Thirty patients with delayed NC (group 1) were matched in a 1-to-1 format with 30 patients without delayed NC (group 2) by age, bone mineral density, body mass index, and medical treatment for osteoporosis. Clinical and radiologic parameters were assessed to determine the risk factors related to delayed NC. Clinical outcomes were also compared between the 2 groups. Neurologic compromises were presented as myelopathy in 20 patients and radiculopathy in 10 patients. Initial kyphotic angle (KA) and height loss (HL) were significantly greater in group 1 (21.6 ± 12.9 degrees vs. 10.5± 8.6 degrees, P= 0.0001 for KA; 55.8% ± 15.2% vs. 19.9% ± 10.9%, P= 0.0001 for HL). Fracture instability with intravertebral cleft, posterior wall involvement, midportion type of magnetic resonance classification, thoracolumbar level, and aortic calcification were significantly correlated with delayed NC. In multivariate analysis, initial HL (hazard ratio= 1.24; P= 0.012) and midportion-type fracture (hazard ratio= 14.9: P= 0.03) were the independent risk factors related to delayed NC. In addition, clinical outcomes at the last follow-up were significantly better in group2. Initial HL and midportion-type fracture were correlated with delayed NC following OSFs. Moreover, pre-existing stenotic lesions might be associated with delayed NC.