Prospective Study to Identify the Clinical and Radiologic Factors Predictive of Pseudarthrosis Development in Patients with Osteoporotic Vertebral Fractures

Abstract

Although most osteoporotic vertebral fractures (OVFs) heal conservatively, the most crucial undesirable outcome of conservative treatment is the failure to unite. There is paucity of literature on prevalence and risk factors of pseudarthrosis. A prospective study involving patients (aged ≥50 years) undergoing conservative treatment of osteoporotic thoracic/lumbar fractures without neurodeficits was performed. Patients were followed for a minimum of 6 months and classified into 3 groups based on fracture healing: group 1, healing without collapse; group 2, healing with collapse; and group 3, pseudarthrosis. An assessment of all clinicoradiologic parameters at the time of injury and at each follow-up was performed and compared among patients belonging to the groups. A total of 77 patients (90 fractures) were studied. Sixty-six (73.3%), 16 (17.8%), and 28 (8.9%) fractures were classified under groups 1, 2, and 3, respectively. Mean ages in groups 1, 2, and 3 were 67.9 ± 9.1, 70.4 ± 7.6 and 72.3 ± 7.9 years (P= 0.08). Sex distribution was 62:15 (female/male). Seventy-three fractures (81.1%) occurred at the thoracolumbar junction. Stiff spine, ambulatory status, comorbidities, bone mineral density, and injury level were not associated with pseudarthrosis/collapse (P > 0.05). Male sex was associated with pseudarthrosis (P= 0.03). Based on regression analysis, initial vertebral height loss (radiography; P= 0.028), segmental Cobb (radiography; P= 0.019), vertebral comminution (computed tomography; P= 0.032), posterior ligamentous complex injury (magnetic resonance imaging; P= 0.048), and marrow change pattern (T2-weighted magnetic resonance imaging, Kanchiku classification; P= 0.037) were correlated with poorer outcome. Patients with pseudarthrosis had higher visual analog scale score (P= 0.04; final follow-up). Of OVFs, 8.9% developed pseudarthrosis. Male sex, severity of postinjury vertebral deformation (vertebral loss, kyphosis, comminution, and marrow changes) and presence of posterior ligamentous complex injury are risk factors for pseudarthrosis.