Treatment of Old Vertebral Compression Fracture With Kyphosis by Different Reconstruction Methods: a Finite Element Analysis

Abstract Background: In repair of vertebral compression fractures, there is a lack of effective biomechanical verification as to whether only half of the vertebral body and the upper and lower intervertebral discs has any effect on spinal biomechanics; there also remains debate as to the appropriate length of fixation.Methods: A model of old vertebral compression fractures with kyphosis was established based on CT data. Vertebral column resection (VCR) and posterior unilateral vertebral resection and reconstruction (PUVCR) were performed at T12; long- and short-segment fixation methods were applied, and we analyzed biomechanical changes after surgery.Results: Range of motion (ROM) decreased in all fixed models, with lumbar VCR decreasing the most and short posterior unilateral vertebral resection and reconstruction (SPUVCR) decreasing the least; in the long posterior unilateral vertebral resection and reconstruction (LPUVCR) model, the internal fixation system produced the maximum VMS stress of 213.25 MPa in a lateral bending motion, and a minimum stress of 40.22 MPa in a lateral bending motion in the SVCR.Conclusion: There was little difference in thoracolumbar ROM between PUVCR and VCR models, while thoracolumbar ROM was smaller in long-segment fixation than in short-segment fixation. In all models, the VMS was greatest at the screw-rod junction and greatest at the ribcage–vertebral body interface, which partly explains the high probability of internal fixation failure and prosthesis migration in these two positions.