Neuroimaging of Spinal Instability

Spinopelvic malalignment correlates to lumbar instability and lumbar musculature in chronic low back pain-an exploratory study

As PI-LL mismatch is an effective index for spinal surgery and PI-LL less than 10 probably indicates better quality of life, this study aimed to assess spinopelvic parameters, lumbar instability, and lumbar muscle morphology in patients with chronic low back pain (CLBP) with different PI-LL mismatches. This cross-sectional study included 158 CLBP patients. The association between lumbar extensor muscle morphology (measured from magnetic resonance imaging) and spinopelvic parameters (measured from standing lateral radiographs) and lumbar instability (measured from lumbar flexion/extension radiographs) was compared between two groups of patients with different PI-LL mismatch. PI-LL mismatch showed a significant medium association with lumbar spine stability (χ2 = 8.06, p-value = 0.005, OR = 0.26, 95% CI = 0.10 to 0.69). Total cross-sectional area (TCSA) (OR = < 0.001, 95% CI = < 0.001 to < 0.001), functional cross-sectional area (FCSA) (OR = < 0.001, 95% CI = < 0.001 to < 0. 001) of the multifidus, psoas major TCSA (OR = < 0.001, 95% CI = < 0.001 to < 0.001) and its FCSA (OR = < 0.001, 95% CI = < 0.001 to 0.009) showed a strong negative association with PI-LL mismatch. Patients with lower PI-LL mismatch are younger and have less spinopelvic deviation. They have more local spinal compensatory mechanisms such as increased lumbar lordosis. They have better lumbar musculature and less disability but more lumbar instability.

AI-based automated detection and stability analysis of traumatic vertebral body fractures on computed tomography

PURPOSE

We developed and tested a neural network for automated detection and stability analysis of vertebral body fractures on computed tomography (CT).

MATERIALS AND METHODS

257 patients who underwent CT were included in this Institutional Review Board (IRB) approved study. 463 fractured and 1883 non-fractured vertebral bodies were included, with 190 fractures unstable. Two readers identified vertebral body fractures and assessed their stability. A combination of a Hierarchical Convolutional Neural Network (hNet) and a fracture Classification Network (fNet) was used to build a neural network for the automated detection and stability analysis of vertebral body fractures on CT. Two final test settings were chosen: one with vertebral body levels C1/2 included and one where they were excluded.

RESULTS

The mean age of the patients was 68 ± 14 years. 140 patients were female. The network showed a slightly higher diagnostic performance when excluding C1/2. Accordingly, the network was able to distinguish fractured and non-fractured vertebral bodies with a sensitivity of 75.8 % and a specificity of 80.3 %. Additionally, the network determined the stability of the vertebral bodies with a sensitivity of 88.4 % and a specificity of 80.3 %. The AUC was 87 % and 91 % for fracture detection and stability analysis, respectively. The sensitivity of our network in indicating the presence of at least one fracture / one unstable fracture within the whole spine achieved values of 78.7 % and 97.2 %, respectively, when excluding C1/2.

CONCLUSION

The developed neural network can automatically detect vertebral body fractures and evaluate their stability concurrently with a high diagnostic performance.

Comparison of the results of open PLIF versus UBE PLIF in lumbar spinal stenosis: postoperative adjacent segment instability is lesser in UBE

OBJECTIVE

To compare the difference in efficacy between open PLIF and UBE for lumbar spinal stenosis and the effect on postoperative adjacent segment instability.

METHOD

The clinical data of 37 patients with PLIF and 32 patients with UBE for lumbar spinal stenosis were retrospectively analyzed to compare the differences in perioperative conditions and short- and medium-term outcomes.

RESULTS

All 69 patients completed the surgery successfully. The operating time, number of intraoperative fluoroscopies and hospital days were higher in the UBE group than in the open PLIF group. Intraoperative bleeding and postoperative drainage were lower than in the open PLIF group (P < 0.05). The visual analogue scale (VAS) of low back pain was lower in the UBE group than in the open PLIF group at 1 month and 3 months postoperatively (P < 0.05), and there were no statistically significant VAS scores for low back pain in the two groups at 1 day and 6 months postoperatively (P > 0.05). Leg pain VAS scores were lower in the UBE group than in the open PLIF group at 1 month, 3 months and 6 months postoperatively (P < 0.05), and leg pain VAS scores were not statistically significant in both groups at 1 day postoperatively (P > 0.05). The ODI index was lower in the UBE group than in the open PLIF group at 1 day and 1 month postoperatively (P < 0.05) and was not statistically significant in the two groups at 3 months and 6 months postoperatively (P > 0.05). There was no statistically significant difference between the two groups in postoperative interbody height, sagittal diameter of the spinal canal, efficacy of modified MacNab and interbody fusion (P > 0.05). The open PLIF group was more prone to postoperative adjacent vertebral instability than the UBE group, and the difference was statistically significant (P < 0.05).

CONCLUSION

With appropriate indications, the open PLIF group and the UBE group had similar short- and medium-term clinical outcomes for the treatment of lumbar spinal stenosis, but patients in the UBE group had better symptomatic improvement than the open PLIF group at 3 months postoperatively, and the effect on postoperative adjacent vertebral instability was smaller in the endoscopic group than in the open PLIF group.

Excessive Fluid in the Lumbar Facet Joint as a Predictor of Radiological Outcomes After Lateral Lumbar Interbody Fusion

Background Preoperative segmental instability maybe a predictor of postoperative outcomes when treated with lateral lumbar interbody fusion (LLIF). An abnormal collection of fluid within the facet joint has been described as a sign of segmental instability. The potential relationship between this radiological sign and its prognostic relevance for indirect decompression (ID) has not been investigated. Methods Clinical and radiologic results from patients undergoing LLIF in a single institution between 2007 and 2014 were evaluated retrospectively. Patients were divided into two groups: those presenting with excessive fluid (EF) in the facet joints on T2-MRI and those with a normal amount of facet fluid with less than 1mm, which were controls. Radiological parameters were foraminal height, disc height, Cobb angle, and lumbar lordosis. Results A total of 21 patients (43 operated levels) were evaluated pre- and postoperatively. Mean disc height, mean foraminal height, and coronal Cobb angles were statistically significantly improved after LLIF. Only the EF group showed significant improvement in radiological markers after ID; the mean disc height improved from 5.5±2 to 8.8±1mm (p=0.001), mean foraminal height improved from 16.88±3 to 20.53±3mm (p=0.002), and the mean Cobb angle improved from 27.7±16 to 14±13 (p=0.018). Conclusions Patients undergoing LLIF with the radiological findings of EF in the facet joints demonstrated significant improvement in radiological outcomes of ID. Further studies should validate these findings in larger data sets.

Factors associated with spinal instability in low back lumbar diseases with leg pain: Analysis of sagittal translation and segmental angulation

BACKGROUND

Determining the association between radiographic spinal instability assessment and lower back lumbar diseases with lower limb symptoms can contribute to evidence-based assessment and treatment in clinical practice and rehabilitation. Therefore, radiological evidence of lumbar spine instability assessment, such as sagittal translation (ST) and segmental angulation (SA), is clinically important.

OBJECTIVE

To identify factors associated with the assessment of spinal instability in lumbar disc herniation with leg pain and discogenic low back pain using ST and SA.

METHODS

We examined 112 patients with lumbar disc herniation with leg pain and 116 with discogenic low back pain at our clinic from 2016 to 2021. Data on age, gender, sports activities, and occupation were collected from medical records. Additionally, ST and SA of L4 and L5 during maximum trunk flexion and extension were measured using radiography. Simple and multiple logistic regression analyses were used for statistical analysis.

RESULTS

Simple logistic regression analysis showed that ST and SA (odds ratio [OR]: 1.11; 95% confidence interval [CI]: 1.03-1.19) were associated with lumbar disc herniation. Multiple logistic regression analysis showed that only ST was associated with lumbar disc herniation (OR: 2.29; 95% CI: 1.78-3.00).

CONCLUSION

Multiple logistic regression analysis showed that ST was associated with lumbar disc herniation with leg pain and had a stronger association than SA.

Combining clinical exams can better predict lumbar spine radiographic instability

BACKGROUND/OBJECTIVES

Several clinical tests have been proposed to diagnose lumbar instability, but their accuracy is still in question. The primary purpose of this study was to evaluate the diagnostic accuracy of the clinical lumbar instability tests. The secondary goal was to design a model to detect lumbar instability.

DESIGN

A prospective diagnostic cross-sectional study.

METHOD

A sample of 202 patients with chronic low back pain were participated in the study. Five lumbar instability tests including Aberrant movement, Passive lumbar extension, Prone segmental instability, H and I and pheasant tests were compared to flexion/extension radiography as the gold standard for diagnosing lumbar instability using two by two tables. Multiple Logistic Regression analysis was applied to develop a model using demographic information as well as the patients' pain intensity, disability level, lumbar lordosis and the clinical tests.

RESULTS

Among the five examined tests, Prone segmental instability, H and I and pheasant tests showed very small likelihood ratios and diagnostic odd's ratio. The largest values were for H and I test with the positive likelihood ratio of 1.28 (95% CI: 0.72 to 2.29) and diagnostic odd's ratio of 1.37 (95% CI: 0.66 to 2.83); the diagnostic accuracy measures were smaller for the other studied clinical tests. The model was developed using weight (t = 1.15, p = 0.03) and lumbar lordosis (t = 3.04, p = 0.00) (which showed a significant relationship with lumbar instability) and prone segmental instability test. The final model has the positive likelihood ratio of 2.07 (95% CI: 1.41 to 3.05) and diagnostic odd's ratio of 3.77 (95% CI: 2.03 to 7.01).

CONCLUSION

Each individual test had very small to no power in discriminating patients with lumbar instability. The developed model just slightly improved the accuracy of radiological instability detection.

An inter- and intra-rater agreement assessment of a novel classification of pyogenic spinal infections

PURPOSE

Pola et al. described a clinical-radiological classification of pyogenic spinal infections (PSI) based on magnetic resonance imaging (MRI) features including vertebral destruction, soft tissue involvement, and epidural abscess, along with the neurological status. We performed an inter- and intra-observer agreement evaluation of this classification.

METHODS

Complete MRI studies of 80 patients with PSI were selected and classified using the scheme described by Pola et al. by seven evaluators. After a four-week interval, all cases were presented to the same assessors in a random sequence for repeat assessment. We used the weighted kappa statistics (wκ) to establish the inter- and intra-observer agreement.

RESULTS

The inter-observer agreement was substantial considering the main categories (wκ = 0.77; 0.71-0.82), but moderate considering the subtypes (wκ = 0.51; 0.45-0.58). The intra-observer agreement was substantial considering the main types (wκ = 0.65; 0.59-0.71), and moderate considering the subtypes (wκ = 0.58; 0.54-0.63).

CONCLUSION

The agreement at the main type level indicates that this classification allows adequate communication and may be used in clinical practice; at the subtypes level, the agreement is only moderate.

Preliminary establishment of a spinal stability scoring system for multiple myeloma

BACKGROUND

Multiple myeloma is an incurable malignant plasma cell disorder that represents the most common primary malignant bone tumor. It commonly involves bone metastasis in multiple vertebral bodies, and the Spinal Instability Neoplastic Score scoring system may not be fully applicable to multiple myeloma (MM) patients.

AIM

To evaluate the spinal stability of patients with MM spinal involvement to guide their clinical treatment.

METHODS

By using the Delphi method, we collected and extracted information through a series of questionnaires and improved it via feedback. We also preliminarily established a spinal stability scoring system for multiple myeloma.

RESULTS

Fifteen clinicians completed a second round of questionnaires and compared their answers with those of the first round of questionnaires to identify significant comments or changes that required group discussions. As a result, no further feedback was used to improve the scoring system. After integrating the information from the expert consultation questionnaire, we established the initial scoring system for MM spine stability and used the scoring system to assess a series of representative clinical cases. The MM spinal stability scoring system was created by calculating the scores of the six separate components: location, pain, number of segments, physiological curvature, comorbidities, and neurological function. The minimum value was “0”, and the maximum value was “24”. A score of “0–10” indicated “spine stability”, a score of “11–17” indicated “potential instability”, and a score of “18–24” indicated “spine instability”. Patients with a score of “11–24” need an intervention such as surgery.

CONCLUSION

The initial establishment of the MM spine stability scoring system provides a vital theoretical basis for the evaluation of spine stability in individuals with MM.

Visualization of the epimysium and fascia thoracolumbalis at the lumbar spine using MRI

BACKGROUND

The fascia thoracolumbalis (FTL) is an important component for stabilization and motion control of the lumbar spine. It coordinates the traction forces of the autochthonous muscles of the back (AM) and connects them to the muscles of the abdominal wall, shoulder, and buttocks.

OBJECTIVES

The aim of our study was to describe the assessment of the normal FTL and epimysium of the AM in MRI and to identify patterns associated with pathological changes in the lumbar spine.

MATERIAL AND METHODS

A total of 33 patients were retrospectively evaluated: 15 patients had no pathology at the lumbar spine; six patients had previous hemilaminectomy, three had spondylodesis, two had ventrolisthesis, and seven had scoliosis. The thickness of the FTL and EM was measured, and the adhesion of both structures was assessed.

RESULTS

The fascial thickness at the levels of the lumbar vertebral bodies LVB 3 was 1.8, of LVB 4 it was 2.0, of LVB 5 it was 2.1, and at the sacral vertebra SVB 1 it was 1.8 mm. Fascial adhesions together with thickening of the EM occurred at the level of LVB 4 in 36% of the cases independently of the underlying disorder. Only thickening of the EM was seen in 48% of cases at the level of SVB 1. By contrast, adhesion of the FTL without epimysial changes occurred in 36% of cases at the level of LVB 3.

CONCLUSION

Thickening and adhesions at the EM and FTL occurred both postoperatively and in the case of scoliosis. Furthermore, lipomatous and muscular herniation could be detected in the FTL postoperatively. Epimysial and fascial alterations may be imaging manifestations of chronic myofascial back pain and should be included in radiological assessments.

Natural Course and Diagnosis of Lumbar Spinal Stenosis: WFNS Spine Committee Recommendations

Lumbar spinal stenosis (LSS) is defined as a degenerative disorder showing a narrowing of the spinal canal. The diagnosis is straightforward in cases with typical neurogenic claudication symptoms and unequivocal imaging findings. However, not all patients present with typical symptoms, and there is obviously no correlation between the severity of stenosis and clinical complaint. The radiologic diagnosis of LSS is widely discussed in the literature. The best diagnostic test for the diagnosis of LSS is magnetic resonance imaging (MRI). However, canal diameter measurements have not gained much consensus from radiologists, whereas qualitative measures, such as cerebrospinal fluid space obliteration, have achieved greater consensus. Instability can best be defined by standing lateral radiograms and flexion-extension radiograms. For cases showing typical neurogenic claudication symptoms and unequivocal imaging findings, the diagnosis is straightforward. However, not all patients present with typical symptoms, and there is obviously no correlation between the severity of stenosis (computed tomography and MRI) and clinical complaint. In fact, recent MRI studies have shown that mild-to-moderate stenosis can also be found in asymptomatic individuals. Routine electrophysiological tests such as lower extremity electromyography, nerve conduction studies, F-wave, and H-reflex are not helpful in the diagnosis and outcome prediction of LSS. The electrophysiological recordings are complementary to the neurologic examination and can provide confirmatory information in less obvious clinical complaints. However, in the absence of reliable evidence, imaging studies should be considered as a first-line diagnostic test in the diagnosis of degenerative LSS.

MRI has limited agreement with CT in the evaluation of vertebral fractures of the canine trauma patient

Complete assessment of vertebral trauma in dogs currently requires CT and MRI for evaluation of the osseous and soft tissue structures that contribute to vertebral stability. Some studies in people have suggested that MRI may be sensitive and specific at detecting vertebral fractures making this potentially a single modality that could be used in spinal trauma evaluation. This study aimed to assess the ability for observers to evaluate vertebral fractures using MRI when compared to CT, which was used as the reference standard. Twenty-nine dogs with previously diagnosed acute vertebral fractures and four dogs with no vertebral fracture that had undergone sequential CT and MRI were included into the study. One hundred twenty-eight vertebrae were evaluated for the presence of fractures. Imaging studies were read by two observers blinded to the history. While both observers had similarly high sensitivity and specificity for simple detection of any fractured vertebrae, interobserver agreement was only moderate (κ = 0.584). When evaluations were specifically limited to detection of structurally unstable fractured vertebrae both observers showed improved specificity and interobserver agreement became substantial (κ = 0.650). Complete agreement for exact fracture location between MRI and CT results was only achieved in 14.3-32.6% of fractured vertebra with up to 79% of fractures being missed in some vertebral structures. This suggests that although MRI may be able to detect the presence of fractured vertebrae, it is not able to replace CT for the complete evaluation of the traumatized spine and documentation of fracture morphology.

Magnetic Resonance Imaging in degenerative disease of the lumbar spine: Fat Saturation technique and contrast medium

Purpose: To examine both anterior and posterior elements of the lumbar spine in patients with low back pain using MRI T2-weighted sequences with Fat Saturation (FS) and contrast enhanced T1-weighted sequences with FS.Materials and methods: Two thousand eight hundred and twenty (2820) patients (1628 male, 1192 female, mean age 54) presenting low back pain underwent MRI standard examination (Sagittal T1w TSE and T2w TSE, axial T1 SE) with the addition of sagittal and axial T2w Fat Sat (FS) sequences. Among all the patients, 987 (35%) have been studied adding Contrast Enhanced (CE) T1w FS sequences after administration of contrast medium. Results: Among 987 patients studied with contrast medium, we found: active-inflammatory intervertebral osteochondrosis in 646 (65%) patients; degenerative-inflammatory changes in facet joints (facet joint effusion, synovitis, synovial cysts) in 462 (47%); spondylolysis in 69 (7%); degenerative-inflammatory changes of the flava, interspinous and supraspinous ligaments in 245 (25%); inflammatory changes of posterior perispinal muscles in 84 (8%) patients. Conclusions: In patients with suspected no-disc-related low back pain, the implementation of T2w FS and CE T1w FS sequences to the standard MR protocol could allow a better identification of degenerative-inflammatory changes more likely associated to the pain. (www.actabiomedica.it)