Session VIII - Pediatrics/Spine

Anterior Stabilization of Three-Column Thoracolumbar Injuries

Robert A. McGuire, MD; Richard C. Sasso, MD; Thomas Reilly, MD, University of Mississippi Medical Center, Jackson, MS

Objectives: Relatively recent advances in anterior instrumentation have resulted in constructs with improved biomechanical stability in the management of thoracolumbar fractures. Previous studies demonstrating excellent results with these devices have largely been limited to the treatment of two-column injuries. The purpose of this study was to evaluate the efficacy of such instrumentation in the management of unstable, three-column injuries as a stand-alone anterior procedure.

Design: Retrospective review of thoracolumbar injuries treated between 1993 and 1997.

Setting: All treatment took place in level I trauma centers in Jackson, MS and Indianapolis, IN.

Patients: Forty patients were identified as having three-column injuries according to the AO Fracture Classification System (type B or C patterns). Canal compromise, kyphosis and neurologic status (ASIA Impairment Scale [AIS]) were determined.

Intervention: All patients underwent anterior decompression, vertebral body reconstruction (Ti mesh cage and/or autograft/allograft), and two-level stabilization with anterior instrumentation: University Plate (AcroMed) or Z-plate (Danek).

Main Outcome Measurements: Correction and maintenance of spinal alignment, clinical neurologic status and fusion status were evaluated.

Results: Average patient age was 38 years (range, 15-70). All injuries occurred within T11-L3, with 34 being classified AO type B and 6 AO type C. Average follow-up was 31 months. Pre-operative canal compromise was Avg 70.5%, while initial angulation was Avg. 22.8°. Early postoperative angulation was corrected to Avg. 8.3 ° (P <0.05). Latest follow-up angulation was Avg. 10.5°, without significant loss of initial correction. Ninety­two percent of those with neurologic deficits demonstrated at least one level of AIS improvement. Solid arthrodesis was achieved in 94.8%. Two pseudoarthroses underwent successful posterior salvage stabilization.

Conclusions: Anterior decompression has previously been shown to result in greater neurologic decompression and improvement in thoracolumbar fracture management than with posterior-only methods. This study shows that some types of three-column injuries may be managed as a single-staged anterior procedure with instrumentation, offering this advantage of direct neurologic decompression, while still providing sufficient stability to maintain sagittal correction and excellent fusion rates.