DIRECT REDUCTION OF THORACOLUMBAR BURST FRACTURES BY MEANS OF BALLOON KYPHOPLASTY WITH CALCIUM PHOSPHATE AND STABILIZATION WITH PEDICLE SCREW INSTRUMENTATION AND FUSION

Abstract

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.

Methods: Twenty-three consecutive patients (average age 48 years) who sustained thoracolumbar A3-type burst fracture with or without neurologic deficit were included in this prospective study. Twenty-one out 23 patients had single fractures and the left 2 had each one additional A1 compression contiguous fracture. On admission 5(26%) out 23 patients had neurologic lesion (5 incomplete, one 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 to L4 fractures. Gardner kyphosis angle, anterior and posterior vertebral body height ratio and spinal canal encroachment were calculated pre–to postoperatively.

Results: All 23 patients were operated within two 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 one ASIA grade, while no neurological deterioration was observed in any case. Overall sagittal alignment was improved from an average preoperative 16o to one degree kyphosis at final follow up observation. The anterior vertebral body height ratio improved from 0.6 preoperatively to 0.9 (P< 0.001) postoperatively, while posterior vertebral body height was improved from 0.95 to 1 (P< 0.01). Spinal canal encroachment was reduced from an average 32% preoperatively to 20% postoperatively. 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: three anterior to vertebral body and one into the disc without sequalae. In the last CT evaluation, continuity was shown between calcium phosphate and cancellous vertebral body bone. Posterolateral radiological fusion was achieved within 6–8 months after index operation. There was no instrumentation failure or measurable loss of sagittal curve and vertebral height correction in any group of patients.

Conclusions: 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 posttraumatic segmental kyphosis and significant spinal canal clearance and restored vertebral body height in the fracture level in an equal amount both in short and long instrumentation.