Traumatic thoracic spinal fracture dislocation with minimal or no cord injury. Report of four cases and review of the literature.

OBJECTIVE

Thoracic fracture dislocations reportedly lead to complete paraplegia in 80% of cases. It is rare for these dislocations not to cause neurological deficits, as evidenced by the mere 11 well-documented neurologically intact cases in the English-language literature.

METHODS

The authors report four cases of thoracic fracture dislocation that remained neurologically intact and discuss 11 other previously published well-documented cases. Overall there were 10 men and five women with a mean age of 34 years (range 17-66 years). Mechanisms of injury included car crash in six, motorcycle crash in seven, plane crash in one, and fall from a horse in one. On admission, neurological deficits were absent in 11 patients, intercostal neuralgia was present in two, and mild lower-extremity weakness/numbness was demonstrated in two. All suffered significant thoracic pain, with 14 patients having sustained rib fractures and eight a hemothorax. The levels of dislocation were T3-4 in two, T5-6 in four, T6-7 in four, T7-8 in two, T8-9 in one, and T9-10 in two. All suffered some degree of lateral translation (mean 12 mm, range 3-27 mm). There were six cases of well-documented anterior subluxation in addition to translation (mean 12 mm, range 4-23 mm), and all involved some degree of fracture imploding of one vertebral body (VB) into an adjacent VB. There were six cases of burst fracture with translation (mean kyphotic angle 38 degrees, range 28-50 degrees). Bilateral pedicle shear fractures were present in all 15 cases at the site of subluxation, thus separating the anterior from the posterior elements and preserving the spinal canal. Only two of the 15 patients suffered complete spondylolisthesis. Five patients underwent successful nonoperative management with prolonged bed rest; at follow-up examination, neurological status remained normal in all five, lesions were radiographically unchanged in three, and there was less subluxation but not anatomical alignment in two. Ten patients underwent successful internal fixation via anterior approaches (two cases), posterior approaches (five cases), and combined approaches (three cases). Neurological status either improved to normal or remained normal except in one case with persistent intercostal neuralgia. Surgery resulted in no change in alignment in three, improved but not anatomical alignment in 11, and normal alignment in one patient. All patients ambulated unassisted by 6 months.

CONCLUSIONS

In cases in which bilateral pedicle fractures occur at the site of significant thoracic subluxation and/or translation, preservation of the spinal canal and spinal cord neurological function can rarely occur when both the lamina and spinal cord do not dislocate along with the anterior VBs. In these instances, perfect anatomical reduction may require forces that unnecessarily put neurological function at risk and the results appear to justify internal fixation with some or no reduction of deformity.