Long-term investigation of nonsurgical treatment for thoracolumbar and lumbar burst fractures: an outcome analysis in sight of spinopelvic balance.

The nonsurgical treatment of thoracolumbar (TLB) and lumbar burst (LB) fractures remains to be of interest, though it is not costly and avoids surgical risks. However, a subset of distinct burst fracture patterns tend to go with a suboptimal radiographic and clinical long-term outcome. Detailed fracture pattern and treatment-related results in terms of validated outcome measures are still lacking. In addition, there are controversial data on the impact of local posttraumatic kyphosis that is associated, in particular, with nonsurgical treatment. The assessment of global spinal balance following burst fractures has not been assesed, yet. Therefore, the current study intended to investigate the radiographical and clinical long-term outcome in neurologically intact patients with special focus on the impact of regional posttraumatic kyphosis, adjacent-level compensatoric mechanisms, and global spine balance on the clinical outcome. For the purpose of a homogenous sample, strong in- and exclusion criteria were applied that resulted in a final study sample of 21 patients with a mean follow-up of 9.5 years. Overall, clinical outcome evaluated by validated measures was diminished, with 62% showing a good or excellent outcome and 38% a moderate or poor outcome in terms of the Greenough Low Back Outcome Scale. Notably, vertebral comminution in terms of the load-sharing classification, posttraumatic kyphosis, and an overall decreased lumbopelvic lordosis showed a significant effect on clinical outcome. A global and segmental curve analysis of the spine T9 to S1 revealed significant alterations as compared to normals. But, the interdependence of spinopelvic parameters was not disrupted. The patients' spinal adaptability to compensate for the posttraumatic kyphotic deformity varied in the ranges dictated by pelvic geometry, in particular the pelvic incidence. The study substantiates the concept that surgical reconstruction and maintenance of a physiologically shaped spinal curve might be the appropriate treatment in the more severely crushed TLB and LB fractures.