RESUMO
Objective To investigate the feasibility of a novel Ni-Ti shape memory alloy vertebral reduction fixator for treating vertebral compression fractures. Methods The experimental thoracic-lumbar fracture units made from adult fresh-frozen cadaver vertebral specimens were randomly assigned to 3 groups for testing: control group, percutaneous kyphoplasty group (PKP group) and percutaneous vertebral body reduction fixator group (Ni-Ti fixator group). The vertebral height and peak load on the specimens were measured before and after the two kinds of operations, respectively, to compare the restoration of compression fractures. Results Compared with the control group, both the PKP and Ni-Ti fixator groups could significantly restore the collapse of the vertebral endplate. The vertebral height of the PKP group and Ni-Ti fixator group was raised from (2.01±0.21) and (2.00±0.18)cm before the operation to (2.27±0.18) and (2.31±0.17) cm after the operation, respectively. The peak loads on the vertebrae for the PKP and Ni-Ti fixator group were (2 880.75±126.17) and (2 888.00±144.69) N, respectively, with no statistical differences found in between, while those for the control group were (2 017.17±163.71) N. Conclusions The Ni-Ti shape memory alloy vertebral reduction fixator can effectively restore the collapse of the vertebral endplate, maintaining the immediate biomechanical stability of the vertebrae, and reducing the adverse reactions due to the injection of polymethyl methacrylate (PMMA) cement during percutaneous kyphoplasty.