Radiographic Outcomes of Thoracolumbar AOSpine A3 and A4 Fractures Treated With External Bracing

Background The treatment of AOSpine A3 and A4 fractures is controversial with no consensus regarding their management in the absence of neurologic deficits. While conservative management with spinal orthosis is a reasonable treatment option, it is believed to run the risk of progressive segmental kyphosis. Methodology A retrospective chart review was conducted of all patients undergoing treatment for thoracolumbar burst fractures from T11 to L2. Patients treated with conservative management with lumbar orthosis were included. Upright radiographs at the time of presentation and the one-year follow-up were compared. Results In total, 112 patients were evaluated as being treated with thoracolumbar orthosis. Of these, 61 patients presented with A3 fractures compared with 51 who presented with A4 fractures. Of these, two patients in each group failed conservative management and required surgical intervention. At the one-year follow-up, A3 fractures demonstrated an average change in Cobb angle of 4.1 degrees compared with 6.1 degrees in A4 fractures (p = 0.021). In addition, A4 fractures demonstrated a significantly worse kyphotic angle and Gardner angle at the one-year follow-up (p = 0.05 and p = 0.026, respectively). Conclusions A3 and A4 fractures can be safely treated with orthosis with overall low rates for failure; however, A4 fractures result in significantly worse segmental kyphosis at the one-year follow-up.