[Anatomic and clinical study of spinal osteotomies for traumatic fixed kyphotic deformity of thoracolumbar spine].

OBJECTIVE

To investigate the safety and efficiency of spinal osteotomies for traumatic fixed kyphotic deformity of thoracolumbar spine with spinal cord injury.

METHODS

Single-level vertebral osteotomies were performed on 3 groups of fresh-frozen human cadaveric lumbar spines. Group 1 underwent a conventional anterior opening-wedge or posterior closing-wedge osteotomy, Group 2 underwent a conventional decancellation posterior closing-wedge osteotomy, and Group 3 underwent the modified decancellation posterior closing-wedge osteotomy. Sagittal plane angulation as well as anterior height and distance of the spinal column were measured before and after osteotomy. In the clinical study, 26 cases of old thoracolumbar fractures with spinal cord injury, 36 years in average, were recruited in this study. The mean time from injury to this operation was 25 months ranging from 3 months to 11 years. Prior to the index surgery, 9 patients received conservative treatment, and 17 patients underwent surgical treatment. There were complete paraplegia in 10 cases and incomplete paraplegia in 14 cases (Frankel B 2 cases, C 10 and D 2). The patients suffered from the low back pain, the average score of VAS was 4.5 (2.5 - 6.0). The patients were found with remained kyphotic deformity of a mean 35 degrees (20 degrees - 75 degrees ). According to the deformity angles, conventional or modified decancellation posterior closing-wedge osteotomy was performed.

RESULTS

On 3 groups of fresh-frozen human cadaveric lumbar spines, the mean correction was (38.0 +/- 2.5) degrees for Group 1, (36.0 +/- 3.6) degrees for Group 2, and (49.0 +/- 2.0) degrees for Group 3. The mean change in anterior height and distance was (13.8 +/- 1.4) mm and (30.2 +/- 2.5) mm respectively for Group 1. For Groups 2 and 3 it was only 2 - 4 mm. In clinical trial, all cases were followed up for 10 months to 6 years, average 12.5 months. Successful decompression and satisfied correction of kyphosis was noticed. The post-operatively mean angle of kyphosis deformity was 10.8 degrees , ranging from 0 degrees to 40 degrees . Neurological functional recovery was noticed in 50% of all cases. For complete spinal cord injury, 30% of cases partially recovered (sensory function), whereas neurological function recovery was noted in 64.3% of cases with incomplete spinal cord injury, a statistical difference was showed between the incomplete and complete spinal cord injury cases (P < 0.01). The score of VAS was 2.3 (1.0 - 3.5) at last follow-up.

CONCLUSIONS

The traumatic fixed kyphotic deformity of thoracolumbar spine with spinal cord injury could be treated with conventional or modified decancellation posterior closing-wedge osteotomy, neurological function and low back pain were expectably recovered.