Abstract: Objective To evaluate the clinical efficacy of lumbar spondylolisthesis treated by laminectomy decompression,vertebral body fusion and RF-Ⅱ pedicle screw spinal system.Methods From February 1999 to December 2003,39 cases of lumbar spondylolisthesis were enrolled in this study.According to Meyerding classification,roentgengram showed that there were 12 cases of gradeⅠ°,18 cases of gradeⅡ°,9 cases of grade Ⅲ°;22 cases of degenerative spondylolisthesis and 17 cases of spondylolysis.All patients were treated with decompression of total laminectomy and bilateral nerve canal,intertransverse process arthrodesis were managed by means of bone chip grafting,interbody fusion was done with RF-Ⅱ pedicle screw spinal system.Results All the patients were followed up over 6months.In the patients with degenerative spondylolisthesis and spondylolysis,the amelioration of nerve function was 81.8% and 82.3% respectively;the improvement of spinal motion was 86.4% and 88.2% respectively;the allevioration of low back pain was 86.4% and 88.2% respectively;the allevioration of leg pain was 90.9% and 94.1% respectively;the mean reduction rate of degenerative spondylolisthesis and spondylolysis was 90.9% and 88.2% respectively.Complications occurred in six cases,in which three cases occurred during operation with the incidence of 7.7%,while the other three occurred after operation with the incidence of 7.7%.Conclusion RF pedicle screw spinal system provide fixation with satisfactory clinical results and relatively high fusion rate.

Key words: RF pedicle screw spinal system, lumbar spondylolisthesis, spondylosyndesis