The distended facet sign: an indicator of position-dependent spinal stenosis and degenerative spondylolisthesis

doi:10.1016/j.spinee.2006.06.379

The Spine Journal

Volume 7, Issue 2, March–April 2007, Pages 245-248

https://doi.org/10.1016/j.spinee.2006.06.379 Get rights and content

Abstract

Background context

Symptoms of spinal stenosis are position-dependent. Stand up magnetic resonance imaging (MRI) and myelography can demonstrate further dynamic components of spinal stenosis that may go unrecognized on supine MRI.

Purpose

To describe a radiographic finding seen on standard supine MRI that is an indicator for dynamic spinal stenosis and degenerative spondylolisthesis.

Study design/setting

Case series.

Patient sample

Six patients.

Outcomes measures

Radiographic observation.

Methods

Six patients with classic neurogenic claudication but equivocal supine MRI findings were evaluated with myelography. The imaging findings were reviewed and compared.

Results

All patients had severe position-dependent spinal stenosis upon upright myelographic imaging with grade I or II spondylolisthesis. The MRI showed very minimal to no spondylolisthesis. These dynamic slips reduced when supine, causing the vertebral bodies to appear aligned with adequate canal space, whereas the irregular facet joints became distended. Hypertrophic and fluid-filled facets at the dynamic slip level were seen in all patients, giving the appearance of a distended joint.

Conclusions

MRI may not demonstrate significant stenosis in patients with neurogenic claudication caused by dynamic degenerative spondylolisthesis. However, the presence of large fluid-filled facet joints indicates the likelihood of positional translation at that level which could be further confirmed by upright imaging.

Introduction

Spinal stenosis is classically a position-dependent clinical syndrome. Neurogenic claudication usually appears when the patient is upright and the lumbar spine relatively extended. This is primarily a clinical diagnosis that is in turn supported by imaging studies. Because this is a dynamic condition, it is intuitive that optimal evaluation would include dynamic features, and it can be assumed that static tests would have limitations, particularly those done supine.

At this time, the two primary imaging studies of choice to evaluate stenosis include magnetic resonance imaging (MRI) and computed tomography (CT)-myelography [1], [2], [3]. Because myelography is done in the upright position, it is an excellent test to evaluate spinal stenosis. However, due to its invasive nature, it is often not the initial study of choice [2], [4], [5], [6]. Stand up MRIs also have the ability to demonstrate dynamic components of stenosis, although these are not yet widely available [1]. If not contraindicated, MRI is most often the initial study performed. Although this test does demonstrate several pathologic features in detail, it can “understate” the degree of stenosis, particularly in the presence of a dynamic spondylolisthesis. This article discusses an MRI finding observed in the presence of a dynamic degenerative spondylolisthesis.

Section snippets

Case series

We report on six patients with classic symptoms and signs of true neurogenic claudication who demonstrated fairly unimpressive stenosis on MRI (Table 1). Additionally, on MRI they had either minimal or no evidence of vertebral body translational deformity (Fig. 1). Because of the classical clinical presentation with relative absence of confirmatory imaging findings on MRI, they were sent for myelography that did show significant stenosis in the upright position (Fig. 2). Standing X-rays also

Discussion

Patients with spinal stenosis are characterized by positional pain differences that are related to position-dependent changes in space available for the nerve roots and their accompanying vascular structures in the lateral recesses and foraminal zones of the spinal column [1], [4], [7], [8], [9]. Upright walking classically causes neurogenic claudication symptoms in patients with spinal stenosis that is relieved by lumbar forward flexion. These position-dependent changes in spinal canal and

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Positional MR imaging of the lumbar spine: does it demonstrate nerve root compromise not visible at conventional MR imaging?
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Cited by (28)

Lumbar Facet Fluid–Does It Correlate with Dynamic Instability in Degenerative Spondylolisthesis? A Systematic Review and Meta-Analysis
2021, World Neurosurgery
Citation Excerpt :
Dynamic spondylolisthesis is most evident in an upright position (either upright radiography or upright MRI) when the spine is under biomechanical forces of weight.5,7 However, most often, MRI is performed in a supine position because upright MRI is not widely available and can miss the dynamic LDS that appears when weight is transmitted through the spine.5,8 It has been postulated and shown by some studies that addition of lumbar fixation to the lumbar decompression yields better outcome in the presence of dynamic spondylolisthesis.9,10
Lumbar degenerative spondylolisthesis (LDS) is a common spinal disease. LDS has been differentiated into dynamic (unstable) and static (stable) spondylolisthesis. Standing flexion/extension lumbar spine radiographs are the best investigation to detect presence of dynamic spondylolisthesis. Magnetic resonance imaging is the investigation of choice to show lumbar canal stenosis and disc prolapse but it can miss dynamic LDS. Studies have shown good association between presence of facet fluid (FF) and dynamic spondylolisthesis.
A systematic review and meta-analysis were performed. All studies describing the relationship between FF and degenerative spondylolisthesis as measured on dynamic radiographs or kinematic magnetic resonance imaging were included.
Fourteen articles met the inclusion criteria. A total of 1065 patients were included in the meta-analysis. Of the patients with unstable spondylolisthesis, 71% had FF, whereas only 22% of the patients with stable spondylolisthesis had FF. The combined pooled odds ratio for unstable spondylolisthesis in the presence of FF was 7.55 (3.61–15.08; P <0.00001). The pooled standard mean difference in the FF size in the patients with unstable and stable spondylolisthesis was 0.97 mm (0.38–1.57; P = 0.001).
FF has positive correlation with the presence of dynamic LDS and the probability of dynamic LDS increases as the size of FF increases. The probability of having a dynamic spondylolisthesis in patients with FF >1 mm is 8 times that of patients with no FF. Standing flexion extension radiographs should be performed in patients with FF >1 mm.
Analysis of the relationship between the facet fluid sign and lumbar spine motion of degenerative spondylolytic segment using Kinematic MRI
2017, European Journal of Radiology
Citation Excerpt :
In the supine position, the translational deformity is relatively reduced by tension of surrounding ligaments creating a potential space between the relaxed facet joint capsule. When viewed on T2-weighted MRI, this space may be identified as an exaggerated fluid signal [24,25]. Hasegawa et al. found facet opening to be the strongest predictor of instability [5].
To investigate the relationship between the facet fluid sign (FFS) and kinematics of affected lumbar segment in patients with low-grade, single-level lumbar degenerative spondylolisthesis using kinematic magnetic resonance imaging (kMRI).Materials and methods Ninety-two patients diagnosed with low-grade (Grade 1 or 2), single level lumbar degenerative spondylolisthesis L3 to S1. Angular and translational motion, whole lumbar motion, slip percentage, and facet angle were measured. Disc degeneration and degrees of osteoarthritis were graded, facet effusion was evaluated and classified as Positive or Negative FFS (PosFFS or NegFFS).Results There were significant differences in the facet degeneration, translational motion, percentage of total angular motion, and flexion-extension slip difference between the PosFFS and NegFFS group. 28.3% of the patients in PosFFS group had anterolisthesis in flexion, but not extension.There was a significant difference in the incidence of FFS between the dynamic and static spondylolisthesis (75% vs 35%, p < 0.001). If FFS was present on kMRI, a positive predictive value for dynamic spondylolisthesis was 75.6%. with the sensitivity and specificity of 0.75 and 0.65 for posFFS to diagnose dynamic DS. The likelihood ratio for dynamic slips in the presence of FFS was 2.1, and the likelihood ratio for static slips in the presence of FFS was 1.1.Conclusion Facet fluid sign was present in weight-bearing neutral position, and the presence of FFS in kMRI increased the probability of having dynamic spondylolisthesis.
Imaging characteristics of "dynamic" versus "static" spondylolisthesis: Analysis using magnetic resonance imaging and flexion/extension films
2014, Spine Journal
Traditionally, the “dynamic” and “static” types of spondylolisthesis have been lumped into a single group in the literature. The goal of this study was to define the radiographic characteristics of “dynamic” and “static” spondylolisthesis with the use of magnetic resonance imaging (MRI) and flexion/extension radiographs.
Describe the characteristic findings present on MRI and flexion/extension radiographs that are associated with dynamic versus static spondylolisthesis.
Retrospective radiographic/imaging study.
From 2009 to 2011, patients who underwent elective primary posterior spinal fusion for the diagnosis of spondylolisthesis had their plain films assessed for the degree of spondylolisthesis and were designated “dynamic” or “static,” as defined by historical measures. Axial and sagittal T2 MRIs were evaluated for associated facet fluid (FF), facet cysts, interspinous fluid (ISF), and facet hypertrophy. These finding were then statistically evaluated for associations between dynamic and static spondylolisthesis on flexion/extension radiographs and characteristic MRI findings.
Ninety patients were included in the study with 114 levels examined for spondylolisthesis. Patients with greater than 3 mm of instability on flexion/extension films were more likely to have FF (p=.018) and ISF (p<.001). Of the patients who had a greater than 3 mm of instability, 39.5% did not demonstrate spondylolisthesis on the sagittal MRI reconstruction. If ISF was present on MRI, there was a positive predictive value of 69.0% that there would be greater than 3 mm instability on flexion/extension films. Absence of FF on MRI had a positive predictive value of 75.6% for instability less than 3 mm on flexion/extension films. In the presence of ISF on MRI, the likelihood ratio of finding more than 3 mm of instability on flexion/extension films was 3.68. The presence of FF on MRI had a likelihood ratio of 1.43 for instability. A total of 36.8% of all spondylolisthesis reduced when supine on MRI.
The presence of FF and/or ISF is associated with instability greater than 3 mm in flexion/extension radiographs.
Comparing postural strategy changes following adapted versus non-adapted responses in subjects with and without spinal stenosis
2010, Manual Therapy
Citation Excerpt :
Spinal stenosis is the narrowing of the spinal canal with subsequent neural compression, which is frequently associated with symptoms of low back pain (LBP). The structural characteristics of such mechanical problems may include postural deficiency, restriction of spinal motion, and loss of lordotic curvature and related functional activities (Ben-Galim and Reitman, 2007; Goldman et al., 2008; Morishita et al., 2009). The narrowing spinal canal can be worsened with trunk extension exercises due to compression.
Musculoskeletal evaluation skills are needed to examine postural compensation techniques, but little is known about ground reaction forces (GRF) in standing posture. Even though a number of studies have evaluated GRF in patients with low back pain (LBP) during vertical perturbations, it would be important to consider compensation characteristics which might be associated with abnormal patterns of postural responses. The vertical excursions of the body center of mass (BCOM) were measured with delay time and normalized amplitude of GRF. Overall, there was no difference based on the vertical excursion of the BCOM (F = 0.12, p = 0.90), amplitude of the normalized GRF (F = 0.16, p = 0.74), or response time (F = 1.98, p = 0.17) between subjects with and without spinal stenosis.
There was a gender difference based on the vertical excursion of the normalized BCOM (F = 5.92, p = 0.02) as well as the normalized amplitude of GRF (F = 4.17, p = 0.04). It was shown that male subjects implemented better adjustment strategies during adapted and non-adapted responses in order to improve body stability. In this way, manual therapists should be aware that gender differences exist in patients with spinal stenosis since the condition may change the individual's postural adjustment ability.
The challenge of diagnosing lumbar segmental instability
2023, Research Square
Specific foraminal changes originate from degenerative spondylolisthesis on computed tomographic images
2023, European Spine Journal

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Case ReportThe distended facet sign: an indicator of position-dependent spinal stenosis and degenerative spondylolisthesis

Abstract

Background context

Purpose

Study design/setting

Patient sample

Outcomes measures

Methods

Results

Conclusions

Introduction

Section snippets

Case series

Discussion

Positional MR imaging of the lumbar spine: does it demonstrate nerve root compromise not visible at conventional MR imaging?

Radiology

Lumbar spine: quantitative and qualitative assessment of positional (upright flexion and extension) MR imaging and myelography

Radiology

Functional MRI of the lumbar spine in erect position in a superconducting open-configuration MR system: preliminary results

J Magn Reson Imaging

Dynamic effects on the lumbar spine: axially loaded CT-myelography and MRI in patients with sciatica and/or neurogenic claudication

Spine

Evaluation of lumbar canal stenosis: decubitus imaging methods versus flexion-extension myelography and surface measurements versus the diameter of the dural sac

JBR-BTR

Case Report
The distended facet sign: an indicator of position-dependent spinal stenosis and degenerative spondylolisthesis