Objective: To analyze the therapeutic effect of the posterior pedicle screw system combined with interbody fusion cage on lumbar spondylolisthesis.
Methods: From February 2003 to March 2006, 37 lumbar spondylolisthesis patients were treated with this operation, including 21 males and 16 females and aging 39-69 years. The affected lumbars were L3 (3 cases), L4 (23 cases), and L1 (11 cases). According to the Meyerding-evaluating system, 12 cases were classified as degree I, 20 cases as degree II, and 5 cases as degree III. Taillard index, Boxall index, slipping angle, lumbar lordosis angle and intervertebral height index were measured before operation, and 2 weeks and 3 months after operation.
Results: All patients were followed up 3-36 months. There were statistically significant differences in Taillard index, Boxall index, slipping angle, lumbar lordosis angle and intervertebral height index between before operation and 2 weeks after operation (P < 0.05), and no statistically significant differences between 2 weeks and 3 months after operation (P>0.05). According to Dewei Zhou's creterior for scoring, the results were excellent in 27 cases, good in 8 cases,and fair in 2 cases. The excellent and good rate was 94.6%. All of the embedded osseous were fused. The fusing time was from 3 to 8 months (mean 3.9 months). There were no breakage of screw and rod. The position and configuration of the whole cages were good.
Conclusion: Applying the posterior pedicle screw system combined with interbody fusion cage may achieve synergism in the treatment of lumbar vertebral spondylolisthesis. Above procedure is served as solid internal fixation and offers a satisfactory reduction, and can improve the fusion rate of the spine. So it is an ideal procedure and worthily recommended method for treatment of lumbar vertebral spondylolisthesis.