RESUMEN
<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>