The correlation between exaggerated fluid in lumbar facet joints and degenerative spondylolisthesis: prospective study of 52 patients

R Caterini,S Bisicchia,F Mancini,P Maglione,P Farsetti

doi:10.1007/s10195-011-0141-3

Abstract

BackgroundMagnetic resonance imaging (MRI) is often used to evaluate low back pain; however, MRI in the supine position does not always reveal degenerative spondylolisthesis. The existence of a linear correlation between increased fluid in the facet joints seen on the supine axial T2 MRI of the lumbosacral spine and lumbar instability seen on standing lateral flexion–extension lumbosacral radiographs has recently been reported. The objective of this prospective study was to determine the incidence of increased fluid in the lumbar facet joints seen on the supine axial T2 MRI, and to evaluate the correlation of this finding with radiographic evidence of lumbar instability.Materials and methodsWe prospectively analyzed weight-bearing flexion–extension lumbosacral radiographs and lumbosacral MRI in the supine position for 52 patients (mean age 64.7 years) seen at our institution for low back pain and/or radiculopathy. The statistical analysis was performed with Fisher’s exact test. A difference was considered statistically significant if P < 0.05.ResultsIn all but 5 of the 52 patients, degenerative disc disease and facet joint disease were observed on the supine MRI of the lumbosacral spine. Fifteen patients had exaggerated fluid in the lumbar facets on the axial T2 MRI (28.8%). Radiographic signs of degenerative lumbar spondylolisthesis were observed in 12 patients (23.1%), and the degenerative spondylolisthesis was not evident on the supine sagittal MRI in 10 of these 12 patients (83.3%). Among these 12 patients, the axial T2 MRI showed exaggerated fluid in the facet joints at the corresponding level in 8 patients (66%). Increased fluid in the lumbar facet joints was present on the supine axial T2 MRI in 7 patients (13.4%), even though there were no radiographic signs of corresponding lumbar instability.ConclusionWe observed a statistical correlation between increased fluid in the lumbar facet joints on the supine axial T2 MRI and degenerative spondylolisthesis seen on standing lateral flexion–extension lumbosacral radiographs.

Highlights

Lumbar spine instability is generally evaluated on standing lateral flexion–extension radiographs, and many studies support the use of these dynamic images [1,2,3]
Increased fluid in the lumbar facet joints was present on the supine axial T2 Magnetic resonance imaging (MRI) in 7 patients (13.4%), even though there were no radiographic signs of corresponding lumbar instability
In 7 patients in our series (13.4%), facet joint effusion was evident on the MRI, but there were no radiographic signs of corresponding lumbar instability

Summary

Introduction

Lumbar spine instability is generally evaluated on standing lateral flexion–extension radiographs, and many studies support the use of these dynamic images [1,2,3]. The existence of a linear correlation between increased fluid in the facet joints seen on the supine axial T2 MRI of the lumbosacral spine and lumbar instability seen on standing lateral flexion–extension lumbosacral radiographs has recently been reported. The objective of this prospective study was to determine the incidence of increased fluid in the lumbar facet joints seen on the supine axial T2 MRI, and to evaluate the correlation of this finding with radiographic evidence of lumbar instability. Radiographic signs of degenerative lumbar spondylolisthesis were observed in 12 patients (23.1%), and the degenerative spondylolisthesis was not evident on Keywords Lumbar spine Á Facet fluid Á Facet degeneration Á Instability

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Conclusion