Study design: Prospective consecutive series.
Objective: To evaluate the outcomes of the treatment of acute thoracolumbar burst fractures by transpedicular balloon kyphoplasty with calcium phosphate cement and posterior instrumented fusion.
Summary of background data: In the surgical treatment of thoracolumbar fractures, the major problem after posterior correction and transpedicular instrumentation is failure to support the anterior spinal column, leading to the loss of correction and instrumentation failure.
Methods: Twenty-three consecutive patients with an average age of 48 years, who sustained thoracolumbar A3-type burst fracture with or without neurologic deficit were included in this prospective study. Twenty-one of 23 patients had single fractures and 2 had each one additional A1 compression contiguous fracture. On admission 5 (26%) of 23 patients had neurologic lesion (5 incomplete, 1 complete). Bilateral transpedicular balloon kyphoplasty was performed with quick hardening calcium phosphate cement to reduce segmental kyphosis and restore vertebral body height and supplementary pedicle-screw instrumentation [long including 4 vertebrae for T9-L1 fractures and short (3 vertebrae) for L2-L4 fractures]. Gardner kyphosis angle, anterior and posterior vertebral body height ratio, and spinal canal encroachment were calculated before to after surgery.
Results: All 23 patients were operated within 2 days after admission and were followed for at least 24 months after index surgery. Operating time and blood loss averaged 70 minutes and 250 cc, respectively. The 5 patients with incomplete neurologic lesions improved by at least 1 American Spine Injury Association grade, whereas no neurologic deterioration was observed in any case. Overall sagittal alignment was improved from an average preoperative 16 degrees to 1 degrees kyphosis at final follow-up observation. The anterior vertebral body height ratio improved from 0.6 before surgery to 0.9 (P < 0.001) after surgery, whereas posterior vertebral body height was improved from 0.95 to 1 (P < 0.01). Spinal canal encroachment was reduced from an average 32% before surgery to 20% after surgery. No differences in preoperative values and postoperative changes in radiographic parameters between short and long group were shown. Cement leakage was observed in 4 cases: 3 anterior to vertebral body and 1 into the disc without sequela. In the last computed tomography evaluation, there was shown a continuity between calcium phosphate and cancellous vertebral body bone. Posterolateral radiological fusion was achieved within 6 to 8 months after index operation. There was no instrumentation failure or measurable loss of sagittal curve and vertebral height correction in any group of patients.
Conclusion: Balloon kyphoplasty with calcium phosphate cement secured with posterior long and short fixation in the thoracolumbar and lumbar spine, respectively, provided excellent immediate reduction of post-traumatic segmental kyphosis and significant spinal canal clearance and restored vertebral body height in the fracture level in an equal amount both in the short and the long instrumentation.