[Factors and revision strategy for failure of thoracolumbar spine internal fixation after burst fracture].

OBJECTIVE

To analyze the reasons for the failure of thoracolumbar spine internal fixation after burst fracture, and to discuss the strategy for revision surgery.

METHODS

From January 2005 to September 2010, 21 patients with thoracolumbar burst fracture received revision surgery after the failure of internal fixation. The etiology included loose of the fixation after anterior surgery in 4 patients, involving malunion with severe kyphosis in 1 patient, pedicle screw malposition in 3, fracture of adjacent segment vertebra in 2, broken of the fixation as non-union of the fracture vertebra in 10 comprising obvious kyphotic deformity in 5, and 2 had developing kyphosis for over distraction of the vertebra followed by pseudarthrosis after removing the internal fixation. After the first operation, symptoms remained in 6 patients, deteriorated in 7, light to moderate improved in 8. Surgical procedures such as anterior corpectomy and reconstruction, replacement of the internal fixation and canal decompression, vertebroplasty, and posterior pedicle subtraction osteotomy were directed based on individual situation.

RESULTS

Patients were followed-up for 6-68 (27.0±13.2) months, and demonstrated solid fusion 6 to 12 months postoperatively. No failure of the internal fixation reccurred. No major complications or deterioration of neurologic status were noted. At the last follow-up, the improvement of Frankel grade was 0-2 (1.3±0.7). The mean visual analog scale (VAS) dropped down from 7.6 to 2.1, and the mean oswestry disability index (ODI) decreased from 48.7 to 10.3. Preoperative angle of 7 kyphotic deformity patients was 10 degree-75 degree (42.5 degree±15.3 degree), and was improved to -3 degree-10 degree (2.3 degree±3.7 degree). At the last follow-up, the loss of correction was 0 degree-1.3 degree (0.7 degree±0.3 degree), with the correction rate of 92.3%.

CONCLUSION

Solid reconstruction of the anterior and middle column of the spine is the imperative procedure to prevent failure of internal fixation in thoracolumbar burst fractures. Revision surgery with reasonable strategy is beneficial and rewarding with few complications.