Various other functional imaging methods have been proposed, such as functional radiographs in seated position and traction/compression radiographs, whereas others claim that flexion/extension in the supine position is preferable to reveal movement in a segment with DS.
The argument for the latter is that pain-induced spasms in the paraspinal muscles are inhibited in supine position and therefore might reveal movement in the segment better than in the standing position.
To investigate whether upright radiographs can predict lumbar spinal canal stenosis using supine lumbar magnetic resonance imaging (MRI) and to investigate the detection performance for spondylolisthesis on upright radiographs compared with supine MRI in patients with suspected lumbar spinal canal stenosis (LSS).
In this retrospective study, conventional radiographs and MR images of 143 consecutive patients with suspected LSS (75 female, mean age 72 years) were evaluated.
Schematic illustration of measurement technique to estimate the degree of sagittal translation.
In sagittal view a line is drawn along the superior endplate of the inferior vertebra (A).This study was approved by the local ethical committee of the University of Zurich, Switzerland.All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.Radiographs are particularly able to demonstrate anterolisthesis of one vertebra relative to the subjacent, without a pars interarticularis defect (Fig. In addition, DS is frequently accompanied by degenerative scoliosis, sometimes even with elements of rotational translation, which might be a diagnostic challenge.Regarding alignment, degenerative spinal changes may, in addition to sagittal translation, lead to a kyphotic disc angle at the affected level.The most common level for DS is L4-L5 followed by L5-S1, with anterolisthesis being most common at L4-L5 and retrolisthesis more common in L5-S1 and in individuals with reduced lordosis.This chapter aims to provide the best imaging strategy in obtaining the DS diagnosis.The range of segmental vertebral mobility in DS is wide, without any universally accepted definition for either the term “instability” or which imaging techniques should be adopted to verify it – uniform reference standards are lacking.To quantify mobility in DS, many doctors employ the use of functional imaging techniques, such as lateral flexion/extension radiographs, since they have the potential to reveal an increased translation. were one of the first to state that flexion/extension radiographs revealed instability, with many followers also claiming that such functional imaging is important for assessing grade of pathological translation in DS. found what they defined as a pathological slip in 11% of their 100 studied spondylolisthesis patients (83% DS) with flexion/extension radiographs, which had not been apparent in standing/recumbent position radiographs.The presence and extent of listhesis (median ± interquartile range) were assessed on upright radiographs and supine MRI of L4/5.In addition, the grade of central spinal stenosis of the same level was evaluated on MRI according to the classification of Schizas and correlated with the severity/grading of anterolisthesis on radiographs.