[Sagittal profile restoration of thoracolumbar fracture with rod rotation and in situ bending technique].

OBJECTIVE

To restore the sagittal profile at the time of regaining vertebral height during surgery of thoracolumbar fracture by rotation, screw-hook combination and in situ bending technique.

METHODS

In 48 patients who have been treated since 1997, 41 were male and 7 female. Their age ranged from 17 to 54 years. Surgical procedures were (L(1) fracture for example): CD or TSRH pedicle screws inserted in T(12) and L(2), offset laminar hooks placed on T(11) and L(2), and two rods contoured according to the normal sagittal profile of the instrumental segment and inserted into the pedicle screws with the rod contouring curve in the frontal plane. Distraction force was used to regain vertebral height. The rods were rotated by 90 degrees and fixed with the set screws. The contouring curve of the rod at this time was transferred from the frontal plane to the sagittal plane where the normal sagittal profile was restored. The offset laminar hooks were compressed toward the screws. If lordosis was not satisfactory, the rods could be bent in situ. Posterolateral bone grafting was finally performed.

RESULTS

No death and no neurological worsening were noted except deep infection in one patient. Average vertebral height was restored by 96%. 39 patients had complete restoration of vertebral height. Sagittal kyphotic Cobb angle was corrected from average 24 degrees before operation to average -2 degrees after operation. Follow-up (20 months on average) showed no pseudarthrosis but two screws broken in one patient.

CONCLUSIONS

Rod rotation and in situ rod bending technique can satisfactorily restore the normal sagittal profile and regain vertebral height. Offset laminar hooks can effectively protect pedicle screws, and minimise mechanical failure of instrumentation.