The aging spine: the effect of vertebral fragility fracture on sagittal alignment

Abstract

In adult spine deformity (ASD), the sagittal imbalance is defined by the deformity in the sagittal plane that causes the need for greater use of muscle strength to maintain an upright static posture or walking. Fragility vertebral fractures (VF) and ASD are frequent causes of spinal morbidity in the elderly. The prevalence of both ASD and VF increases with aging. Although these two clinical conditions insist on the same population, little is known about the interactions between sagittal imbalance and vertebral fracture (VF) deformity. The aim of our work is to examine the associations between vertebral fractures, sagittal alignment, and their impact on the quality of life scores in elderly patients. A retrospective cohort study of 110 patients of both sexes, from a spine surgery waiting list, with at least one VF with ≥ 5° of kyphosis and a full-standing X-ray. the presence of VF with kyphotic deformity ≥ 10°, fracture level, degree of kyphosis (deformity) of the fracture, number of fractures, spinopelvic angular parameters, demographic parameters, and scales of evaluation of the health-related quality of life. A total of 110 patients with mean age 73.8 ± 5.2, of which 70 women (63%) were included in the study. Subjects with at least one VF ≥ 10° presented greater disability and an overall worse sagittal spinal alignment (no VF10° vs VF10°: TPA 21.30 ± 11.5 vs 26.51 ± 12.6, p = 0.041) and more disability (no VF10° vs VF10°: ODI 41.91 ± 16.9 vs 54.67 ± 15.8, p < 0.001) than patients with less degree of vertebral deformity. Significant compensatory mechanisms involved the thoracic area and the lower lumbar region. Kyphotic VFs were associated with severe alterations of sagittal spine alignment and perceived disability. Subjects with sagittal imbalance have a greater degree of deformity in the thoracolumbar junction area. Thoracic hypokyphosis and lower lumbar hyperlordosis are effective compensatory mechanisms in case of lumbar or thoracic fracture, respectively.