An invitro biomechanical study of treatment for lumbar spondylolithesis using nail-grooved tail steel plate and intervertebral implant (Wendeng Fusion Cage, WDFC) / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the biomechanics of treatment for lumbar spondlolisthesis using nail-grooved tail steel plate and WDFC (Wendeng Fusion Cage) implant.</p><p><b>METHODS</b>There were nine permanent waist-sacrum wet bone (L3-S3) in 1 to 2 clay-cold hours including 6 men and 3 women. They were seldom separated into 3 groups, which were fixed by nail-grooved fail plus WDFC. The model was separate into two kinds for single and across. With electrometry, deal experiment date with Graftool software. Each piece should be tested twice respectively.</p><p><b>RESULTS</b>The single and across segment non-destructive compression experiment. No-mid-compression from 0 to 750 N,the related coefficient and curves had no obvious change on inclined rate. In the single segment curvedly serial experiment, the stress at all point measured by two sides steel plate-was mostly linear growth. In the across segment curvedly serial experiment, the inclined rate become big and appear anisomerous.</p><p><b>CONCLUSION</b>It's proved by biomechanics that the steel plates with single furrow and cylinder wing plus WDFC has a good stability to cure lumbar vertebra slips.</p>

Treatment of lumbar spondylolisthesis by posterior restoration and three-column fixation / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the late results of using posterior restoration and three-column fixation to treat lumbar spondylolisthesis.</p><p><b>METHODS</b>One hundred and eighty-four patients with lumbar spondylolisthesis were collected from March 1999 to May 2007, they were treated by posterior restoration and fixation with single nail-grooved tail steel plate and fixed with cage (WDFC). Among these cases, 87 cases were fixed with one WDFC, 97 cases were used two WDFCs.</p><p><b>RESULTS</b>All patients were followed up for 8 to 69 months(averaged 23 months). According to Nakai standard, the results was excellent in 142 cases, good in 34, fair in 8, the excellent and good rates were 95.6%. Seventy-nine vertebraes with I degree spondylolisthesis were reduced after surgery. Eighty-seven vertebraes with II degree spondylolisthesis were reduced except 9 with I degree spondylolisthesis left. Twenty-one with III degree spondylolisthesis were reduced except 5 with I degree spondylolisthesis left; In 2 with IV degree spondylolisthesis, one with I degree spondylolisthesis left and the other with II degree spondylolisthesis left. The follow-up results showed that there was no statistical significance in the height of intervertebral space between preoperation and post-operation, and no recurrence was observed and no single nail-grooved tail steel plate and WDFC were loose or crashed.</p><p><b>CONCLUSION</b>Posterior restoration and three-column fixation is a positive modus operandi to treat lumbar spondylolisthesis,which can reduce excellently,keep the height of intervertebral space and stabilization of segment, obtain high rate of fusion, and cut down complication.</p>