Location of Vertebral Fractures is Associated with Bone Mineral Density and History of Traumatic Injury.

Abstract

The upper and lower thoracolumbar spine have been associated with different biomechanical outcomes. This concept, as it applies to osteoporotic fracture risk, has not been well documented. This was a case-control study of 120 patients seen in an osteoporosis clinic. Vertebral fractures were identified from lateral radiographs using Genant's semi-quantitative assessment method. An association between bone mineral density (BMD) T-scores and vertebral fracture location was assessed. In an additional analysis, the association between a history of any traumatic injury and possible predictor variables was also explored. The median age of patients was 75 (IQR 67-80), and 84.2% of patients were female. A history of trauma was reported by 46.7% of patients. A vertebral fracture in the lower thoracolumbar spine (T11-L4) was associated with significantly higher femoral neck (p < 0.001), lumbar (p = 0.005), trochanteric (p = 0.002), intertrochanteric (p < 0.001), and total hip (p = 0.0006) BMD T-scores. The odds of having a femoral neck (OR 0.24, 95% CI 0.07-0.75, p = 0.01) or total hip (OR 0.19, 95% CI 0.06-0.65, p = 0.008) T-score less than -2.5 was also lower among patients with vertebral fractures in the lower thoracolumbar spine. A fracture in the upper thoracolumbar spine (T4-T10) decreased the odds of having a history of traumatic injury (OR 0.32, 95% CI 0.14-0.76, p = 0.01), while a non-vertebral fracture increased the odds of such an injury (OR 2.41, 95% CI 1.10-5.32, p = 0.03). Vertebral fractures in the lower thoracolumbar spine are associated with higher BMD T-scores. This should be studied further to understand possible correlations with patients' future fracture risk.