Background: Spontaneous thoracic ankylosis is a progressive degenerative process that predisposes patients to potentially highly unstable traumatic injuries. Acute hyperextension fractures result in dynamic instability putting the spinal cord at risk.
Objective: To describe preoperative radiographic characteristics of fractures of the ankylotic thoracic spine and relate findings to early postoperative radiographic and clinical outcomes.
Methods: A single center, retrospective review was performed of 28 surgically treated patients with fractures of the ankylotic thoracic spine. Radiographic assessment included preoperative fracture angulation (FA) and fracture displacement (FD), and postoperative change in sagittal alignment. Early clinical outcomes included preoperative and postoperative American Spinal Injury Association (ASIA) grade and perioperative complications.
Results: Seven patients (25%) presented with poor neurological grade (ASIA A-C) compared to 21 (75%) with good grade (ASIA D, E). At presentation, poor grade patients had a mean FA of 16.4° (range 0°-34.5°), and FD of 7.76 mm (range 0.8-9.2). Good grade patients had a mean FA of 18.2° (range 0°-43.3°), and FD of 4.77 mm (range 0-25.1). There was no statistically significant difference in FA or FD between groups (P = .70 and .20 respectively). All underwent posterior pedicle screw fixation for stabilization. Fifty per cent of patients presenting with ASIA C or D spinal cord injury improved 1 or more ASIA grades. There were no perioperative complications. Early postoperative sagittal alignment was maintained with a mean change of -2.6°.
Conclusion: Presenting fracture alignment does not significantly correlate with pre- or postoperative neurological status. Early posterior stabilization preserved neurological function, with neurological recovery occurring in a portion of individuals.