RESUMO
STUDY DESIGN: A prospective radiological assessment was conducted. OBJECTIVES: To analyze the changes in the height of the intervertebral disc, the slippage, slip angle, lumbar lordotic angle and sacral inclination after anterior lumbar interbody fusion and posterior pedicle screw fixation in a lumbar spondylolisthesis. SUMMARY OF LITERATURE REVIEW: The anterior lumbar interbody fusion causes changes in the lumbar sagittal alignment. METHODS: The mini-open anterior lumbar interbody fusion and pedicle screw fixation was undertaken in 33 cases from April 1995 to November 2003. MRI was done before and 6 months after surgery. The measuring factors were the heights of the intervertebral disc, slippage, slip angle, lumbar lordotic angle and sacral inclination. The measuring factors were independently assessed three times by three different orthopedic surgeons. The postoperative changes in measuring the factors were analyzed by a paired t-test statistically. RESULTS: The height of the intervertebral disc was increased by a mean of 14.0%, slippage was reduced by a mean of 2.8%, the slip angle was reduced by a mean of 16.0%, the lumbar lordotic angle was increased by a mean of 15.6% and the scaral inclination was increased by a mean of 3.0%. There was significance in the increase in the disc height, the reduction of slippage and the slip angle, and the increase in lumbar lordotic angle, but there were no significance regarding the changes in sacral inclina-tion. CONCLUSIONS: The anterior lumbar interbody fusion and the pedicle screw fixation significantly improved the height of the intervertebral disc, slippage, slip angle, and lumbar lordotic angle, except sacral inclination.
