The Study On Stability After Lumbar Vertebrae Operation

Objective:To measure the intervertebral angle and sliding distance in the spine at flexion and extension position before and after the disc replacement surgery, traditional laminectomy, fixation/fusion surgery respectively by using the X-ray, then analyze the result of the measurement and discuss whether there is instability after traditional laminectomy and the influence of different operative methods to the mobility in surgery section. To observe whether there is any degeneration occurred in the adjacent segment and whether there is any change in the lumbar lordosis angle preoperatively and postoperatively.Methods:1 Inclusion criteria:All the patients had the low back pain. Among those patients, there were 34 patients who were carried out traditional laminectomy, including 16 males and 18 females, aged 41-74 years, mean 57.58 years; the intertransverse fusion operation of the lumbar vertebra by internal fixation with screws in the neck of vertebral arch 26 cases, including 11 males and 15 females, aged 39-73 years, mean 54.46 years; 15 patients were applied disc replacement,6 male and 9 female, aged 32-59 years, mean 47.22 years. Follow-up time was 1 to 4 years; All patients underwent dynamic lumbar spine x-ray films with flexion and extension exposures during their follow-up period.2 Measurement of X-ray photographs:to measure the angular displacement and horizontal displacement in the spine Lordotic Kyphotic position respectively. To measure the angle of lumbar lordosis in lateral X-ray film and observe the degenerative changes of those segments.3 All of cases were found degenerative changes preoperatively, some patients with lumbar instability and spondylolisthesis. To observe whether there is any instability and the influence of intervertebral mobility after the operation of traditional laminectomy, pedicle screw fixation and disc replacement; Evaluate the stability and instability after operation by multivariate analysis. To observe the degeneration close to the cephalic segment and the changes of lumbar lordosis angle after operations. Reveal the relationship between lumbar lordosis angle and postoperative discomfort.Results:1 Three patients were found instability after traditional laminectomy. It depended on the range of rear resection and the age and there was nothing to do with gender.2 The range of lumbar mobility had a decreasing trend before and after traditional laminectomy, but there was no statistical significance. The mobility of vertebral disappered after pedicle screw fixation and the change had a statistical significance(P<0.05); The average retained intervertebral mobility is 4.6°, no statistical changes was found in stability before and after disc replacement.3 There was no significant difference in the degenerative condition of adjacent cephalic segment before and after surgery.4 The angle of lumbar lordosis in the pedicle screw fixation/fusion and traditional laminectomy had a trend to decrease, but there was no significant difference above items between before and after operation (P>0.05).The angle of lumbar lordosis had the trend to increase under disc replacement surgery. There was no significant difference between before and after total disc replacement surgery (P> 0.05).Conclusion:Ttraditional laminectomy may not result in lumbar spinal instability; the range of surgical resection is the unstable factors. Fixation/fusion increases the stability while it sacrifices the intervertebral activities of the surgery segment. Disc replacement retains vertebra activities and it is more in accordance with lumbar structure characteristics. After three surgeries, there is no significant degenerative change in adjacent segment in any groups. Lumbar degeneration has its own characteristics or follow-up time was short, Traditional laminectomy and fusion surgery will decrease the lordosis angle; Disc replacement may increase the lordosis angle.