OBJECTIVETo explore the feasibility of using transpedicular balloon kyphoplasty for aged osteoporotic thoracolumbar burst fractures with an in vitro model.

METHODSSimulated osteoporotic thoracolumbar burst fractures were created in 11 vertebral bodies. The burst fractures without obvious canal occupation were confirmed by spiral CT before the procedure. This operation involved the percutaneous insertion of two inflatable bone tamps into a fractured vertebral body transpedicularly under fluoroscopic guidance. Inflation of the bone tamp elevated the endplates, restored the vertebral body height, while created a cavity to be filled with bone cement. Preoperative and postoperative heights were measured, preoperative and postoperative sagittal diameter of vertebral canals were measured, and the repaired vertebral bodies were compressed to determine strength and stiffness values. The cement distribution and extravasation was evaluated by spiral CT after the procedure.

RESULTSThe transpedicular balloon kyphoplasty resulted in the significant restoration of the vertebral body height. The mean vertebral body heights was (20.73 +/- 1.37) mm before operation and (24.82 +/- 1.61) mm after operation (P < 0.01). Preoperative and postoperative sagittal diameter of vertebral canals were similar (P > 0.05). The cement distribution was regular, and the extravasation into spinal cannula was found in one case. The preoperative strength was significantly larger than the postoperative strength, whereas the postoperative stiffness was significantly less than the preoperative stiffness (P < 0.05).

CONCLUSIONSTranspedicular balloon kyphoplasty is an effective way to treat aged osteoporotic thoracolumbar burst fractures without obvious canal occupations and neurologic deficit in vitro. The procedure can increase strength and restore height of aged osteoporotic thoracolumbar burst fractures. Cement distribution and vertebral canal stenosis can be avoided.