Clinical and radiological factors affecting progressive collapse of acute osteoporotic compression spinal fractures

Osteoporotic compression spine fractures have a different clinical course and outcomes when compared to spinal fractures occurring in the younger population. Only a few studies have investigated the risk factors for progressive osteoporotic compression spine fractures. The purpose of this study was to investigate clinical and radiological factors related to progressive collapse following acute osteoporotic compression spine fractures. We retrospectively identified all patients treated for thoracolumbar fractures in our institution between January 2008 and July 2013. Included cases were examined by plain radiographs and CT scans. For each patient we classified the fracture according to the AOSpine Thoracolumbar Spine Injury Classification System. The difference between initial and final height loss and initial and final local kyphosis was documented as height loss difference and kyphotic angle difference. The presence of old fractures and intravertebral cleft were also documented. The study included 153 patients, comprising 102 women and 51 men. The mean patient age was 68.9 years. The mean length of follow up was 15 months. A statistically significant correlation was found between patient age, final height loss, height loss difference and kyphotic angle difference. Height loss difference and kyphotic angle difference were significantly correlated to type of fracture according to the AO classification system. The height loss difference was 18.1% in A1 type fractures, 27.1% in A2 type fractures, 24.2% in A3 type fractures and 25.7% in A4 type fractures. During a minimum 3-month follow up of conservative treatment for acute osteoporotic vertebral compression fractures, age and the AOSpine Thoracolumbar Spine Injury Classification System were predictive factors for progressive collapse.