Experimental And Clinical Studies Of Torch Pedicle Internal Fixation Instrument

Recent decades, satisfactory results have been achieved for thoracolumbar fracture and lumbar spondylisthesis with short-segment posterior pedicle internal fixation instrument. However, the reported complications of the instrumentation should appeal to our emphases, which associated with not only operative procedure , making material and procedure of the instrument, but also the instrument's design and selecting proper indicative patients. To improve the reduction and fixation effects of the pedicle instrument , simplify the procedure and decrease the complications, we carried out the following studies:1. The design of Torch pedicle internal fixation instrument:On the basis of concluding the past experiments of the pedicle instruments clinical applications, we designed a new pedicle internal fixation instrument-Torch.2. The biomechanical studies of Torch pedicle internal fixation instrument:Firstly, after selecting thoracolumbar spine from T12 to L5 out of 10 adult fixture cadavers, we made spinal injury models, including fracture in 7 models and sponylisthesis in 3 models. Secondly, we fixed the models with the designed Torch pedicle instrument and compared with that of other pedicle instruments. Finally, after biomechanical testing, it showed: In fracture group testing, there was no significant difference(p>0.05) between Torcrh, SF and modified RF in strength, stiffness and stability , but better than that of SF, modified RF in some points, at the same time there was significant difference(p<0.05)between Torch and Dick. In sponylisthesis group testing, the result was similar, there was no significant difference(p>0.05) between Torch and RF but converse results (p<0.05) between Torch and Steffee. The Torch instruments do show its feasible implant in the test. So we concluded that Torch instrument was not only better in biomechanics but also simpler in surgical procedure, and it was worthy of clinic applications.3. The preliminary clinical application of Torch pedicle internal fixation instrument:We have treated 16 patients with Torch pedicle instrument in clinic till now, including fracture in 12 patients and spondylisthesis in 4 patients. Fourteen patients were followed up from 2 month to 10 month, the preliminary results were satisfactory, those complications such as vertebrae height losing, pedicles screws breakage and loosening , vertebrae spondylisthesis increasing et al were not found. It shows that fixation with Torch instrument is stiff, and the implant procedure is easy. Because the follow-up time isn't very long, the final results depend on long-time follow-up and further studies.