Fixation of thoracolumbar fractures with the Dick fixator: the influence of transpedicular bone grafting

Summary

Fifty patients with thoracolumbar fractures were treated by internal fixation using the Dick fixator. In the first 22 patients (group 1) this was accompanied by posterior intertransverse grafting. The technique was then modified in the following 28 patients (group 2) to include transpedicular elevation of the depressed vertebral end plate and grafting of the vertebral body, in an attempt to reduce the postoperative loss of correction of the kyphotic deformity. The clinical records and X-rays were reviewed to determine whether the change in technique had achieved this objective and whether it affected operative time, blood loss, postoperative recovery and complications. The mean operating time and blood loss in group 1 were 2 h, 38 min and 650 ml, respectively, and in group 2 2 h, 59 min and 783 ml. These differences were not statistically significant. Time from operation to mobilisation and discharge from hospital were related to neurological deficit, but there was no significant difference between group 1 and group 2 in this regard. There was no difference in the complication rate between the two groups and no complication attributable to transpedicular bone grafting. The radiological results postoperatively and at a mean follow-up period of 9 months were assessed by measurement of the kyphosis angle, anterior vertebral height, anterior displacement, scoliosis, and reduction in cross-sectional area of the spinal canal. In group 1 the mean preoperative kyphosis angle and anterior vertebral height were 8° and 21 mm; postoperatively these values were −12° (lordosis) and 27 mm; and at follow-up they were −4° and 24 mm. In group 2 the mean preoperative kyphosis angle and anterior vertebral height were 9.7° and 16 mm; postoperatively these values were −11° and 31 mm; and at follow-up they were −6° and 30 mm. The difference in the restoration and maintenance of anterior vertebral height between the two groups was statistically significant. The mean reduction of canal cross-sectional area for all patients preoperatively was 56%. The mean postoperative reduction of canal cross-sectional area was 23%. It is concluded that use of the Dick fixator for thoracolumbar fractures produces marked correction of the kyphosis angle and restoration of anterior vertebral height and a moderate restoration of canal cross-sectional area. The correction of the kyphosis angle and anterior vertebral height is greater and maintained better in the postoperative period if transpedicular bone grafting of the vertebral body is also performed.