Development of lumbar intervertebral spreader and its clinical application in the treatment of spondylolisthesis

YIN Zhixun; HE Erxing; GUO Jing; CHEN Jingchen; GUO Lianjin; GAO Juzhou

doi:10.3969/j.issn.1674-666X.2015.05.002

Abstract：Objective To design and develop a lumbar intervertebral spreader with independent intellectual property rights for expanding the intervertebral space,and to discuss the application value in the reduction of lumbar spondylolisthesis.Methods According to the anatomic characteristics of Chinese human lumbar spine,a set of intervertebral spreaders with increasing thickness was designed on the Solidworks software platform,and made by a medical apparatus manufacturer.With this self-designed device,12 patients of lumbar spondy-lolisthesis with serious intervertebral stenosis underwent unilateral transforaminal interbody spondylolisthesis reduction combined with bilateral percutaneous pedicle screw-rod internal fixation from July 2013 to July 2014 in First Affiliated Hospital of Guangzhou Medical College,and their clinical data were analyzed retrospectively. The interbody traction and reduction during the operation were observed,and the relative complications were recorded.Results The average operative time was 110 min (90-150 min),the average intraoperative estimate blood loss was 150 mL (120-300 mL).No nerve root or dural injuries were found during the procedure.The patients were followed up from 3 to 15 months (average,7.5 months).At 1 week,3 months after the surgery,as well as the last follow-up,visual analogue scale (VAS) scoring,intervertebral space height and the distance of lumbar spondylolisthesis were all improved compared with preoperative ones (P <0.05); At the last follow-up,the average improvement rate of VAS of back pain and leg pain was 68.9%,68.1% respectively,and the improvement rate of lumbar spondylolisthesis was 91.8%.There was complete reduction in 5 cases,and nearly complete reduction in 7 cases.No screw-rod breakage or Cage migration,subsidence had happend during the follow-up.Conclusion The self-designed lumbar intervertebral spreader has been proved to be safety and practical which is effective for expanding intervertebral space with severe stenosis,so as to be helpful for the reduction of lumbar spondylolisthesis.