The Effect of the Pedicle-Facet Angle on Degenerative Cervical Spondylolisthesis

OBJECTIVE: To measure the orientation of the facet joints of cervical spine (C-spine) segments in the sagittal plane, known as the pedicle-facet (P-F) angle, and to use these measurements to evaluate the relationship between the P-F angle and the amount of vertebral anterolisthesis in patients with degenerative cervical spondylolisthesis (DCS). METHODS: A retrospective case-control study was performed including 30 age- and sex-matched patients with DCS and 30 control participants. Anterior-posterior and lateral view radiographs of the C-spine were obtained in a standing position. The P-F angle at all cervical levels and the amount of anterolisthesis at C4-5 were measured from lateral view plain radiographs. RESULTS: The P-F angles at C4-5 were 141.14+/-7.14degrees for the DCS group and 130.53+/-13.50degrees (p=0.012) for the control group, and at C5-6 were 137.46+/-8.53degrees for the DCS group and 128.53+/-16.01degrees for the control group (p=0.001). The mean P-F angle at C4-5 did not correlate with the amount of anterolisthesis (p=0.483). The amount of anterior slippage did correlate with age (p<0.001). CONCLUSION: The P-F angle was intrinsically higher at C4-5, compared to C5-6, in both the DCS and control groups, which might explain the increased likelihood for anterolisthesis of C4. Higher P-F angles in the DCS group may be a predisposing factor to slippage. The P-F angle may interact with age to increase incidence of anterolisthesis with increasing age.

Pseudospondylolisthesis (Review of 22 Cases)

Study of 22 cases with the pseudospondylolisthesis established that it occurred more frequently in the older women, and far more frequently at the L4 level, as same results as reported by others. The slipping occurred as a result of degenerative disease of the articular process and facet joint, but it never exceeded 25% in this series. This study was performed to recognize the stability of the lumbosacral joint by the measurement of the anterior and posterior vertical heights(deformity) of the body of the L5 vertebra and lumbosacral angles in our cases. We also attempted to observe whether the facet angle changes at the involved level was meaningful or not. Result : lumbosacral angles in the our patients with pseudospondylolisthesis were increased greater than normal, so lumbar lordosis was less than normal. The body of the L5 vertebra was not as wedged anteroposteriorly as it normally was. The contour of the body of the L5 vertebra resembled rectangle shape. The pedicle-facet angles were increased at involved level, but this measurement was not correctly demonstrated on the plain roentgenograms. Conclusion : The stability of the lumbosacral joint in the patients with pseudospondylolisthesis was increased due to rectangle shape of the body of the L5 vertebra and less lumbar lordosis. The pedicle-facet angles at the involved level were increased, but not correct diagnostic values.