Effect of subsequent vertebral body fractures on the outcome after posterior stabilization of unstable geriatric fractures of the thoracolumbar spine

PURPOSE: The purpose of this study was analyzing the effect of subsequent vertebral body fractures on the clinical outcome in geriatric patients with thoracolumbar fractures treated operatively. METHODS: Retrospectively, all patients aged ≥ 60 with a fracture of the thoracolumbar spine included. Further inclusion parameters were acute and unstable fractures that were treated by posterior stabilization with a low to moderate loss of reduction of less than 10°. The minimal follow-up period was 18 months. Demographic data including the trauma mechanism, ASA score, and the treatment strategy were recorded. The following outcome parameters were analyzed: the ODI score, pain level, satisfaction level, SF 36 score as well as the radiologic outcome parameters. RESULTS: Altogether, 73 patients were included (mean age: 72 years; 45 women). The majority of fractures consisted of incomplete or complete burst fractures (OF 3 + 4). The mean follow-up period was 46.6 months. Fourteen patients suffered from subsequent vertebral body fractures (19.2%). No trauma was recordable in 5 out of 6 patients; 42.8% of patients experienced a low-energy trauma (significant association: p < 0.01). There was a significant correlation between subsequent vertebral body fracture and female gender (p = 0.01) as well as the amount of loss of reduction (p = 0.02). Thereby, patients with subsequent vertebral fractures had significant worse clinical outcomes (ODI: 49.8 vs 16.6, p < 0.01; VAS pain: 5.0 vs 2.6, p < 0.01). CONCLUSION: Patient with subsequent vertebral body fractures had significantly inferior clinical midterm outcome. The trauma mechanism correlated significantly with both the rate of subsequent vertebral body fractures and the outcome. Another risk factor is female gender.