The effect of posterior instrumentation of the spine on canal dimensions and neurological recovery in thoracolumbar and lumbar burst fractures.

A prospective study was designed to determine whether posterior instrumentation of the spine in thoracolumbar and lumbar burst fractures produces indirect decompression of the spinal canal leading to better remodeling and neurological recovery. The study was conducted in Kasturba Medical College Manipal, India. Sixty-eight consecutive cases of thoracolumbar and lumbar burst fractures were treated by posterior instrumentation, and approval from the hospital ethical committee was obtained. The degree of initial spinal canal compromise, indirect decompression, and remodeling were assessed from the computed tomography scans. The neurological status at the time of presentation and at final follow-up was assessed by the American Spinal Injury Association's modified Frankel's grading. The median canal compromise in patients with and without neurological deficit was 47.32 and 39.33%, respectively. The overall mean canal compromise at the time of admission, post-operative, and final follow-up were 47.37, 26.58 and 14.85%, respectively (P = <0.001). The median canal compromise in patients who recovered was 44.5% and in those with no neurological recovery was 55.85%. The median percentage of canal decompression achieved in patients who recovered was 22.15%, whereas it was 22% in those who did not recover. The median remodeling in recovered and non-recovered groups was 64.50 and 80%, respectively. None of these differences was statistically significant. This study shows that posterior instrumentation of the spine produces significant indirect decompression of the spinal canal and better remodeling. However, these factors may not improve the neurological recovery.