[Long term radiological outcomes of unstable thoraco-lumbar fractures without neurological deficit]

To analyse the radiological outcomes in the long term of unstable thoraco-lumbar fractures.

Retrospective review of 100 patients with unstable thoracolumbar fractures treated with posterolateral fusion and short screw fixation for compression and flexion-distraction type fractures, and long segment posterior fixation for fractures-dislocations or more than one vertebra fractured, between 2000 and 2010 at three different hospital centers. Six radiological parameters were measured annually during a 4-year period: Fracture angle, kyphotic deformity, sagittal index, percentage of compression, degree of displacement and deformation angle.

A total of 100 patients were included with a median age of 36,4 years and a median follow-up period of 7.2 years. Fracture angle rose from 11,6° to 14,5° (increase of 25%), kyphotic deformity from 14,5° to 16,7° (increase of 15,17%), sagittal index from 8,7 to 10,8 (increase of 24,13%), percentage of compression from 31,8% to 36,5% (increase of 6,88%), degree of displacement from 2,8mm to 4,6mm (increase of 14,77%) and deformation angle from 19.7° to 21.4° (increase of 8,62%).

All the radiological parameters studied lost correction throughout the 48 months of follow-up, being the fracture angle the most affected one. Nevertheless, the greatest loss of correction occurs in the first postoperative year, stabilizing the parameters afterwards over the 4 years of follow up. We routinely recommend the measurement of all previous parameters for the follow up of unstable thoracolumbar fractures.