The Design And Biomechanical Evaluation Of A New Reduction-fixation Device For Lumbar Spondylolisthesis

Spondylolisthesis is a main reason for back pain occurred very popularly in clinic, with a occurrence of about 5-6% in adult population, some especially people reach up to 20%, for instance athletes, which always leads to lumbar pain. Although they still didn t draw a conclusion on the treatment of spondylolisthesis. The majority of patients can be treated conservatively. However, those who have persistent pain that is unresponsive to conservative measures, operative interventions seems to be necessary, which bone grafting with the effective internal fixation is the universal solution. The majority of scholars proposed the reduction-pedicle screw fixation-back intervertebral fusion method. This study aimed to introduce and evaluate a new reduction-fixation device (NRF).Two parts are comprised in this paper.The first part: The design of a new reduction-fixation device(NRF) for lumbar spondylolisthesis.1. Existing device design principles: To analysis design principles and structural characteristics of RF- II device and CF-1 device for lumbar spondylolisthesis (RF- II device is a classic fixation device, and CF- I device is newly introduced fixation device).(1) RF- II device taking the next adjacent upholding screw as the lever fulcrum, using angle connective bar which can resume physical curve cone of lumbar and produce a "correct excessive" role when RF- II device is fixed, is to draw out and reduce the slippage body. It has many advantages:â‘  Simple structure: RF- II device is a classic fixation device for lumbar spondylolisthesis. Compared with other devices, RF- II device match biomechanics...