Segmental Instability In Patients Research Articles

214. MRI proxies for segmental instability in degenerative lumbar spondylolisthesis patients

<h3>BACKGROUND CONTEXT</h3> Lumbar degenerative spondylolisthesis (LDS) has a heterogeneous nature. Some patients have a dynamic component of segmental instability associated with LDS which complicates the surgical treatment. The radiological diagnosis of instability has been based on dynamic radiographs. But studies have shown that magnetic resonance imaging (MRI) can show signs of instability. These MRI proxies (MRIPs) for instability involves disc height, facet joint angle and effusion. <h3>PURPOSE</h3> To investigate whether findings on MRI can be proxies for segmental instability in patients with degenerative lumbar spinal stenosis (LSS) and/or LDS. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study. <h3>PATIENT SAMPLE</h3> Patients with LSS or LDS at L4/L5 scheduled for decompressive surgery with or without fusion from 2010 to 2017, with preoperative standing lateral spine radiographs and supine lumbar MRI and enrolled in Danish national spine surgical database, DaneSpine, 2-year follow-up. <h3>OUTCOME MEASURES</h3> Radiograph: sagittal translation (slip, mm). MRIPs for instability: sagittal translation (slip, mm), facet joint angle (FJA, degree), facet joint effusion (mm), disc height index (DHI, %) and presence of vacuum phenomena. <h3>METHODS</h3> Instability was defined as slip of > 3 mm on standing lateral radiographs. Patients were divided into two groups based on presence of instability. Slips >3mm were considered unstable and slips 3 mm on radiograph as the dependent variable and MRIPs for instability as independent variables. <h3>RESULTS</h3> A total of 232 patients in the cohort divided into two groups: 47 in the stable group and 185 in the unstable group. The two groups were comparable with regard to baseline patient-reported outcome measures (PROMs). Cut points for MRIPs for instability: bilateral FJA = 46°(AUC: 0.644, 95 % CI: [0.566 – 0.722]); bilateral facet effusion = 1.5mm (AUC: 0.601, 95 % CI: [0.536 – 0.666]) and DHI = 13 % (AUC: 0.613, 95 % CI: [0.537 – 0.689]). Logistic regression showed statistically significant association with > 3mm slip on MRI (OR: 221.5; SE: 201.0; 95% CI [37.4 – 1311.5]; p<0.001), bilateral FJA = 46°(OR: 5.6; SE: 3.0; 95% CI [1.9 – 16.1]; p=0.002), bilateral facet effusion = 1.5 mm (OR: 4.5; SE: 2.5; 95% CI [1.5 – 13.7]; p=0.009) and DHI = 13 % (OR: 9.1; SE: 7.5; 95% CI [1.8 – 46.0]; p=0.007). ROC curve with an AUC 0.951. In the absence of slip on MRI logistic regression showed statistically significant association between instability on radiograph and the remaining MRIPs: bilateral FJA = 46°(OR: 3.1; SE: 1.4; 95% CI [1.3 – 7.3]; p=0.008), facet effusion = 1.5 mm(OR: 2.4; SE: 0.9; 95% CI [1.2 – 4.9]; p=0.017) and DHI = 13 % (OR: 12.7; SE: 13.1; 95% CI [1.7 – 96.1]; p=0.014). ROC curve with AUC 0.757. <h3>CONCLUSIONS</h3> Presence of MRIPs for instability defined as >3 mm slip on MRI, bilateral FJA = 46°, bilateral facet effusion = 1.5 mm and DHI = 13% showed statistically significant association with instability and excellent ability to predict instability on standing radiograph at L4/L5 in LSS and LDS patients. Even in the absence of slip on MRI the MRIPs had a good ability to discriminate presence of instability. Further studies will determine whether presences of MRIPs makes radiographs obsolete at diagnosing segmental instability. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Magnetic Resonance Imaging Proxies for Segmental Instability in Degenerative Lumbar Spondylolisthesis Patients.

Retrospective cohort study. The aim was to investigate whether findings on magnetic resonance imaging (MRI) can be proxies (MRIPs) for segmental instability in patients with degenerative lumbar spinal stenosis (LSS) and/or degenerative spondylolisthesis (LDS) L4/L5. LDS has a heterogeneous nature. Some patients have a dynamic component of segmental instability associated with LDS. Studies have shown that MRI can show signs of instability. Patients with LSS or LDS at L4/L5 undergoing decompressive surgery±fusion from 2010 to 2017, with preoperative standing lateral spine radiographs and supine lumbar MRI and enrolled in Danish national spine surgical database, DaneSpine. Instability defined as slip of >3mm on radiographs. Patients divided into two groups based upon presence of instability. Outcome measures: radiograph: sagittal slip (mm). MRIPs for instability: sagittal slip >3mm, facet joint angle (°), facet joint effusion (mm), disk height index (%), and presence of vacuum phenomena. Optimal thresholds for MRIPs was determined by receiver operating characteristic (ROC) curves and area under the curve (AUC). Logistic regression to investigate association between instability and MRIPs. Two hundred thirty-two patients: 47 stable group and 185 unstable group. The two groups were comparable with regard to baseline patient-reported outcome measures. Thresholds for MRIPs: bilateral facet joint angle ≥46°; bilateral facet effusion ≥1.5mm and disk height index ≥13%. Logistic regression showed statistically significant association with MRIPs except vacuum phenomena, ROC curve AUC of 0.951. By absence of slip on MRI logistic regression showed statistically significant association between instability on radiograph and the remaining MRIPs, ROC curve AUC 0.757. Presence of MRIPs for instability showed statistically significant association with instability and excellent ability to predict instability on standing radiograph in LSS and LDS patients. Even in the absence of slip on MRI the MRIPs had a good ability to discriminate presence of instability.

Pain Control Affects the Radiographic Diagnosis of Segmental Instability in Patients with Degenerative Lumbar Spondylolisthesis.

Background: Diagnosing intervertebral instability is crucial for the treatment of degenerative lumbar spondylolisthesis (DLS). Disabling back pain will reduce spinal mobility which leads to an underestimate of the incidence of intervertebral instability. We hypothesized that adequate analgesia could alter the flexion/extension exam performance, and thus increase the diagnostic accuracy of segmental instability. Materials and methods: One hundred patients with low-grade DLS were prospectively enrolled in the before–after cohort study. Standing lateral flexion/extension radiographs of lumbar spines were examined and analyzed before and after intramuscular injections of 30 mg ketorolac. Results: Pain score decreased significantly after analgesic injections (p < 0.001). Dynamic slip (DS), dynamic segmental angle (DA), dynamic lumbar lordosis, and slip percentage (SP) were significantly increased after pain reduction (all p < 0.001). According to the diagnostic criteria for segmental instability (DS > 4.5 mm, DA > 15°, or SP > 15%), there were 4%, 4%, and 0.7% of total motion segments fulfilling the criteria which markedly increased to 42%, 32%, and 16.7% after analgesia was administered. The incidence of instability also increased from 6% to 38% after analgesia. Conclusions: The diagnosis rate of intervertebral instability is commonly underestimated in the presence of low back pain. This short-term pain relief facilitates reliable functional imaging adding to the diagnosis of intervertebral instability.

Bilateral facet effusion is a risk factor for segmental instability with cervical injury without vertebral fracture

Magnetic resonance imaging (MRI) is effective in identifying cervical spine injury after trauma. However, cervical instability without major bone injury or dislocation is challenging to assess. Hence, the current study aimed to investigate and compare the MRI and radiography findings of segmental instability in patients with cervical spine injury. We investigated 34 participants with cervical spine injury without vertebral fracture. Based on the radiography findings, the participants were categorized into two: group A with segmental instability (n = 11) and group B without segmental instability (n = 23). Both groups were compared in terms of the presence of segmental instability on radiography and MRI. Anterior longitudinal ligament (ALL) injury, disc injury, and bilateral facet effusion were observed in 6/11, 5/11, and 7/11 patients in group A and in 5/23, 2/23 and 7/23 patients in group B, respectively. The results showed significant differences (p < 0.05). Moreover, 2 and 10 of 11 patients in group A and 16 and 7 of 23 patients in group B presented with hemi lateral facet effusion and paravertebral muscle injury, respectively. However, the results did not significantly differ. According to a logistic regression analysis, bilateral facet effusion after trauma was associated with cervical segmental instability (odd ratio: 10.6, 95% confidence interval: 1.31–84.7). Facet joint effusion might be caused by capsule injury during trauma. Most participants with segmental instability had ALL, disc, and flavum injury and bilateral facet effusion. Therefore, we need to consider bilateral facet effusion with other soft tissue damage of the cervical spine as an association factor to show the instability.

IMAGE CORRELATION BETWEEN FACET EFFUSION AND LUMBAR INSTABILITY

ABSTRACT Objective To assess the incidence of facet effusion in lumbosacral spine magnetic resonance imaging (MRI) and the relationship with radiographic segmental instability in patients submitted to spinal surgery. Methods Retrospective cohort study of patients submitted to lumbosacral spine surgery over a period of three years, through the evaluation of dynamic radiographs (X-ray) motion and facet effusion in axial section of MRI. Instability was defined as vertebral translation &gt; 3 mm or intervertebral angle &gt; 10º, and facet effusion as fluid in the facet joints &gt; 1.5 mm. Results The total number of patients that fulfilled the criteria for analysis was 244, of which 47 presented movement (≤ 3 mm) and 31 presented excessive movement (&gt; 3 mm), 115 had facet effusion (≤ 1.5 mm) and 46 presented excessive fluid (&gt; 1.5 mm). Statistical analysis did not demonstrate a significant association between increased segmental movement and facet effusion (p = 0.150). Conclusions The total incidence of facet effusion was 47.1% and the excessive fluid was 18.9%.There was no association between facet effusion in MRI and instability in dynamic X-ray. MRI does not replace dynamic X-ray in flexion and extension in the evaluations of lumbar instability. Level of evidence III; Retrospective Cohort.

MRI findings of lumbar spine instability in degenerative spondylolisthesis.

To find out the factors suggesting lumbar segmental instability in patients with degenerative spondylolisthesis (DS) on conventional magnetic resonance imaging (MRI). Ninety-four patients with DS who underwent decompression surgery with or without fusion were selected. Patient demographics and findings on simple radiographs and MRI were analyzed. We divided patients into two groups by the presence of lumbar instability on simple standing plain radiographs and measured degeneration status of intervertebral discs and facet joints and distance of facet fluid signal on T2 axial MRI on each groups. The data were analyzed to find out the correlation between facet fluid signal and lumbar instability. Sixty-three patients were confirmed to have lumbar instability (unstable group (UG), 67%), while 31 patients (stable group (SG), 33%) did not have instability on simple radiographs. The mean age was slightly older in SG ( p < 0.05) and SG patients' degeneration status of intervertebral discs and facet joints was advanced than UG patients. Fifty-five of 63 patients had high signal intensity on T2-weighted MR images in the UG, but only 4 of 31 patients had high signal intensity in the SG ( p < 0.001) and UG patients have more larger facet joint distance than SG patients ( p < 0.001). High signal in facet joints on T2 MR images can be a useful factor suggestive of lumbar instability. Thus, the identification of fluid signal in the facet joints on MRI should raise the suspicion for lumbar instability and prompt additional evaluations such as with stress radiographs.

Radiological evaluation of lumbosacral spine for post discectomy segmental instability.

Aim To establish presence of segmental instability in patients operated with standard discectomy comparing measurement of translation and rotation on postoperative functional radiographs of lumbosacral spine with reference values,and to explore difference between patients operated on one or two levels. Methods The study included 71 patients, who were operated due to herniated lumbar disc. They were divided into two groups operated on one level (group A) or two adjacent levels (group B). All patients had been imaged in a standing position with functional lateral radiography. Radiographic images were digitized and then computerized measurement of translation and rotation was made. Measurement data were compared between the groups and with reference values obtained in healthy adults. Results Standard lumbar discectomy leads to an increase in translation, however, it reached statistical significance only for L4/L5 level and a decrease of rotation, which showed statistical significance for all samples, relative to the reference values. There was no statistically significant difference in the values of translation and rotation between the groups for corresponding levels, except for the value of the rotation for L4/L5 level as adjacent, unoperated level. Comparison of translation and rotation between the operated and adjacent levels did not show a statistically significant difference. When it comes to comparing the measured and predicted translation, there was a statistically significant difference only at the L5/S1 as anunoperated level. Conclusion Standard discectomy does not lead to radiologically significant segmental instability, and two-level surgery has not caused more pronounced signs of instability comparing to onelevel surgery.

Evaluation of Spinal Instability after Single Level Fenestration Discectomy: A Prospective Study

Introduction: Failed back surgery syndrome (FBSS) represents a clinical condition of patients that undergo one or more surgical procedures for lumbosacral disease and still present unsatisfactory long-term relief of symptoms, with persistent or recurrent low back pain. One of the sources of failed back surgery syndrome is segmental instability of the lumbar spine. There is very limited evidence in the literature regarding the incidence of spinal instability following fenestration and discectomy. Materials and Methods: This study was conducted on 50 patients who were between 17 and 52 years and who had undergone fenestration discectomy for a single-level lumbar intervertebral disc prolapse. Results: Results were evaluated using Prolo economic and functional outcome scoring which showed good outcome in 41 (82%) patients and moderate outcome in 9 (18%) patients after fenestration. Clinical instability as per criteria was noted in 9 (18%) patients post operatively while radiological instability was noted in 1(2%) patient . All 9 (100%) patients with clinical instability showed a moderate outcome. 13(26%) patients showed a decrease in the disc height more than 30% as compared with there preoperative images before lumbar fenestration. Patients with radiological sign of instability showed a good outcome. Conclusion: Standard fenestration discectomy does not destabilize the spine. Further studies are required to truly evaluate the development and progression of segmental instability in patients treated for lumbar disc herniation using different surgical methods.

Spontaneous Reduction Finding: Magnetic Resonance Imaging Evaluation of Segmental Instability in Spondylolisthesis

Study DesignRetrospective chart review.PurposeTo assess whether spontaneous reduction of spondylolisthesis, as seen on magnetic resonance imaging (MRI), is related to the degree of segmental instability and low back pain.Overview of LiteratureThe flexion-extension radiographs obtained in the sagittal plane are frequently used when segmental instability of spondylolisthesis is evaluated.MethodsWe retrospectively reviewed 137 patients and measured the differences of the percentage of sagittal translation and sagittal angulation to determine the segmental instability between the flexion and extension radiographs, and the spontaneous reduction on MRI. We then compared the degrees of segmental instability and the degrees of spontaneous reduction. To assess the effect of low back pain on segmental motion in regards to the flexion-extension radiographs, we compared the preoperative visual analogue scales (VAS) score for low back pain between the more and the less spontaneous reduction groups.ResultsThe mean degree of spontaneous reduction was 5.2%. A statistically significant correlation was found between the sagittal translation on the flexion-extension radiographs and the degree of spontaneous reduction (r = 0.557, p < 0.001) and between the sagittal angulation on the flexion-extension radiographs and the degree of spontaneous reduction (r = 0.215, p = 0.012). The preoperative VAS scores for low back pain of the more spontaneous reduction group and the less spontaneous reduction group were 4.6 and 3.6 points, respectively, and this difference was statistically significant (p = 0.002).ConclusionsSpontaneous reduction of spondylolisthesis on MRI was found to be closely related to segmental instability, and the degree of spontaneous reduction seen on MRI could be useful for the evaluation of segmental instability in patients with spondylolisthesis, especially with severe low back pain.

Efficacy of segmental stabilization exercise for lumbar segmental instability in patients with mechanical low back pain: A randomized placebo controlled crossover study

Efficacy of segmental stabilization exercise for lumbar segmental instability in patients with mechanical low back pain: A randomized placebo controlled crossover study

Efficacy of segmental stabilization exercise for lumbar segmental instability in patients with mechanical low back pain: A randomized placebo controlled crossover study.

Background:Lumbar segmental stability is an important biomechanical component that influences symptoms amongst patients with Mechanical low back pain.Aims:To compare the efficacy of segmental stabilization exercises utilizing multifidus and transversus abdominis muscles versus a placebo treatment in patients with lumbar segmental instability.Materials and methods:The study was an observer-blinded randomized placebo-controlled cross-over study of 18 adults (12 men, 6 women), of mean age 22.5 ± 1.09 yrs who scored 7/13 in subjective aspects and 8/14 in objective aspects of Delphi criteria for lumbar segmental instability. The selected subjects were then randomized to receive either placebo-control (prone lying) or experimental (lumbar segmental stabilization) as a first treatment. Each treatment was followed by a wash-out period of 24 hours. Outcomes were measured four times- pre- and post- first intervention, pre- and post- second intervention. The outcome measures used were pain on Visual analogue scale, Pressure pain threshold and Joint play grading scale (0-6 scale) on that level.Results:Two-way analysis of variance and post-hoc analysis using Bonferonni test were used with level of significance set at p<.05 using Statistical package for social sciences version 12.0.1 for Windows. Visual analogue scale changed significantly in both the periods of intervention- in control (P =.016) and experimental (P =.000) periods. However this improvement was more significant in the experimental period. The Joint play grading scale scores improved only in the experimental condition compared to the control condition significantly. The Pressure pain threshold also improved significantly in the experimental condition (P =.000) while the changes in control condition was not statistically significant (P=.816).Conclusion:Segmental stabilization exercise was more effective than placebo intervention in symptomatic lumbar segmental instability.