Thoracolumbar Anterolateral and Posterior Stabilization

Background

The thoracic and lumbar regions are the most common anatomic sites for vertebral fractures. The thoracolumbar area is especially susceptible to trauma, accounting for 52% of all thoracic and lumbar fractures. The most common fracture types in the thoracolumbar region are the vertebral body compression fractures (AO types A1 and A2), followed by burst fractures (type A3), then translation–rotation injuries (types B and C). Associated spinal cord injury is found in up to 30% of these patients.

Treatment of thoracolumbar vertebral fractures remains controversial despite nearly four decades of widely accepted surgical treatment. The majority of type A1 and A2 injuries can be treated nonsurgically with good functional results. Common indications for surgical treatment include instability of the affected spinal segment, incomplete or complete neurologic deficit, and persistent pain despite adequate nonoperative treatment. Instability of the spine is a poorly defined entity, but it is generally agreed to consist of vertebral height loss greater than 50%, a kyphotic angle of more than 20 degrees, and spinal canal compression of more than 50% of its area as a measure of posterior vertebral wall injury. Other determinants of spinal instability are high-energy fracture patterns such as translational and rotational fracture dislocations and injury to the posterior ligamentous complex (PLC).

Clinical Evaluation

Detailed history and thorough physical and neurologic examination are mandatory. Concomitant injuries including intracranial visceral and spinal injuries at other levels are very common in the setting of high-energy vertebral fractures and must be fully assessed. Before designing a treatment plan, plain radiograph and computed tomography (CT) scans are performed ( Figs. 163.1 and 163.2 ). Magnetic resonance imaging (MRI) of the affected spine area is useful for evaluating soft-tissue injury, including the intervertebral disc and the PLC, as well as for identifying epidural hematomas and spinal cord lesions ( Figs. 163.3 and 163.4 ). The accuracy of MRI in identifying PLC injuries has been questioned, ^, and refined diagnostic criteria are still required. Goals of surgical treatment are reduction of the fracture and reconstruction of the normal spinal architecture, stable fixation of the affected spinal segment, decompression of the spinal cord, and prevention of new spinal cord injuries. Additional goals include early mobilization and optimal medical and surgical treatment in polytrauma patients.