Wedge osteotomy for treating post-traumatic kyphosis at thoracolumbar and lumbar levels.

Local post-traumatic kyphosis may impair spinal sagittal balance and result in severe disability. The goal of this study is to evaluate posterior closing wedge osteotomy at the level of injury, by comparing thoracolumbar (T12-L1) and lumbar (L2-4) spinal levels. Thirteen consecutive patients had surgery in an average 13 months after the initial injury. There were 8 thoracolumbar and 5 lumbar deformities. Nine patients already had posterior fixation. Eight patients had preoperative neurological deficits. Sagittal correction was assessed in terms of regional angulation (RA) and effective regional deformity (ERD), which was defined as the difference between the actual RA and the physiological RA for the level. The average follow up was 2.1 years. The average RA passed from 43.8 degrees (31 to 55) to 2.2 degrees (-5 to 7) after surgery. It was 5.3 degrees (-4 to 12), at follow-up. RA and surgical correction were not significantly different between thoracolumbar and lumbar groups. The average ERD was 47.2 degrees (24 to 66) preoperatively and 8.6 degrees (-5 to 37) at follow-up. The ERD passed from 41.8 degrees (24 to 54) to 0.5 degrees (-5 to 6) in the thoracolumbar group, and from 55.8 degrees (50 to 66) to 21.6 degrees (17 to 37) in the lumbar group. The ERD was significantly different initially (P=0.014) and after surgery (P=0.06). The anatomical result was complete in the thoracolumbar group, because the correction of the deformity at this level does not require more than correction of the vertebral body kyphosis. On the contrary, due to adjacent disc damage, the technique did not fully restore the physiological regional lordosis at lower levels.