Magnetic resonance imaging of the alar and transverse ligaments in acute whiplash-associated disorders 1 and 2: a cross-sectional controlled study

[Atlas block and alar ligament lesion-Underestimated or overrated?]

BACKGROUND

Disorders of the upper cervical spine, most notably lesions of the alar ligament and atlas block, are associated with numerous symptoms, especially as reported in the lay press. Thus, physicians are often confronted with patients who see in them a monocausal origin of complex complaints and hope for a quick remedy.

OBJECTIVE

This review article presents the currently available evidence-based literature on atlas block and alar ligament lesions in order to adequately appreciate their significance.

MATERIAL AND METHODS

Summary and critical evaluation of an extensive review of the literature on the diagnostics, clinical presentation, and treatment of disorders of the upper cervical spine.

RESULTS

The current literature shows that alar ligament lesions are caused only by extremely high-speed trauma and that the reliability of their detection on magnetic resonance imaging (MRI) is moderate at best. As several studies have failed to demonstrate a correlation between symptoms and abnormalities of the alar ligaments on MRI, surgical stabilization of the upper cervical joints is not indicated. The diversity of symptoms associated with atlas block may be explained by the convergence of afferent neurons originating in C1-C3 on several cranial nerve nuclei found in neuroanatomical studies, but this association has yet to be proven. First studies show that highly significant improvements in cervical pain and range of motion can be achieved by means of manual therapy of the upper cervical spine with lasting effects even after 6 months.

CONCLUSION

The importance of alar ligament lesions has often been overrated in the past; however, a more nuanced multifactorial understanding of the disorder should be conveyed to the patient. An atlas block should be considered mainly as a possible cause of pain and restricted range of motion of the cervical spine and in this context manual therapy can be an effective treatment option.

Demonstration of transverse ligament on 3D SPACE MRI in whiplash-associated disorder and nontraumatic conditions

PURPOSE

This study aims to delineate the three-dimensional (3D) SPACE MRI findings of the transverse ligament (TL) in whiplash-associated disorder (WAD) patients, and to compare them with those from a nontraumatic group.

METHODS

A retrospective analysis was performed on cervical spine MRI scans obtained from 46 patients with WAD and 62 nontraumatic individuals. Clinical features, including the WAD grade and stage, were recorded. The TL's morphological grade and the symmetricity of the lateral atlantodental interval was assessed using axial 3D T2-SPACE images. The morphological grading was evaluated using a four-point scale: 0 = homogeneously low signal intensity with normal thickness, 1 = high signal intensity with normal thickness, 2 = reduced thickness, 3 = full-thickness rupture or indistinguishable from surrounding structures. Additionally, the number of cervical levels exhibiting degeneration was documented.

RESULTS

When comparing the WAD and nontraumatic groups, a significant difference was observed in the proportion of high-grade TL changes (grade 2 or 3) and the number of degenerated cervical levels. Logistic regression analysis revealed that high-grade TL changes and a lower number of degenerative levels independently predicted the presence of WAD. Within the WAD group, the subset of patients with high-grade TL changes demonstrated a significantly higher mean age than the low-grade group (grade 0 or 1).

CONCLUSION

High-grade morphological changes in the TL can be detected in patients with WAD through the use of 3D SPACE sequences. Clinical relevance statement 3D SPACE MRI could serve as an instrumental tool in the assessment of TL among patients with WAD. Integrating MRI findings with patient history and symptomology could facilitate the identification of potential ligament damage, and may help treatment and follow-up planning.

Do measures of physical function enhance the prediction of persistent pain and disability following a whiplash injury? Protocol for a prospective observational study in Spain

INTRODUCTION

Not all factors that predict persistent pain and disability following whiplash injury are known. In particular, few physical factors, such as changes in movement and muscle behaviour, have been investigated. The aim of this study is to identify predictive factors that are associated with the development of persistent pain and disability following a whiplash injury by combining contemporary measures of physical function together with established psychological and pain-related predictive factors.

METHODS AND ANALYSIS

A prospective observational study will recruit 150 consecutive eligible patients experiencing whiplash-related symptoms, admitted to a private physiotherapy clinic in Spain within 15 days of their whiplash injury. Poor outcome will be measured using the Neck Disability Index (NDI), defined as an NDI score of 30% or greater at 6 months post injury. Candidate predictors, including demographic characteristics, injury characteristics, pain characteristics, self-reported psychosocial factors and physical factors, will be collected at baseline (within 15 days of inception). Regression analyses will be performed to identify factors that are associated with persistent neck pain and disability over the study period.

ETHICS AND DISSEMINATION

The project has been approved by the Ethics Committee of the province of Malaga, Spain (#30052019). The results of this study will be published in peer-reviewed journals.

Inter-examiner reliability of radiographic measurements from Open-mouth lateral bending cervical radiographs

Background

Following head and neck trauma, the involvement of the cranio-cervical junction (CCJ) and its contribution to a patients transition to chronic pain, is poorly understood. The detection of hypermobility in this region is dependent on clinical examination and static imaging modalities such as x-ray, CT and MRI. Sagittal plane hypermobility of the CCJ is evaluated using saggital view, flexion-extension cervical radiographs. Frontal plane hypermobility is typically assessed using lateral bending and open mouth cervical radiographs. Unfortunately there is no established reliability surrounding the use of these measures. This study explores the reliability of radiographic measurements of lateral-bending open-mouth cervical radiographs.

Methods

Cervical open-mouth lateral-bending X-ray images were collected from 56 different patients between 18 and 60 years of age patients following cervical spine injury. These images were interpreted by two musculoskeletal radiologists and two clinicians (physiatrist and chiropractor), using a standard set of measurements. Measurements included qualitative and quantitative assessments of the amount of asymmetry noted between various osseous landmarks. Reliability statistics were calculated for levels of agreement using kappa coefficients (κ) and Intraclass Correlation Coefficients (ICC) for dichotomous and continuous variables, respectively.

Results

Reliability (κ) for qualitative assessments were moderate to substantial for asymmetry of neutral C2 spinous position, dens-lateral mass spacing, and “step off” between the lateral borders of the articular pillars of C2 and C1 lateral mass (κ range = .47–.78). ICC values for the quantitative measurements of dens-lateral mass spacing and “step off” between the lateral borders of the C2 articular pillars and C1 lateral mass were moderate to excellent (ICC range = .56–.97).

Conclusions

The qualitative and quantitative measurements used in this study demonstrated good to excellent inter-examiner reliability. Correlation with clinical findings is necessary to establish the utility of these measurements in clinical practice.

Signal changes of the alar ligament in a healthy population: a dispositional or degenerative consequence?

OBJECT The alar ligaments (ALs) are vital for stabilizing the craniocervical junction. In terms of morphology, their appearance varies and is visible on MRI. Dark signal of the AL on proton-density (PD)-weighted images is generally considered the norm, but the etiology of frequently observed signal hyperintensities is poorly understood. Using spectral fat suppression, signal hyperintensities can be differentiated into fat- and nonfat-related hyperintensities (NFH). Although signal hyperintensities have no evident association with whiplash-associated disorder, age-related degeneration has often been theorized. Therefore, this study investigates the signal intensities of the ALs on 3.0-T MRI with special reference to age. Expanding thereon, the authors investigated the relationship between signal hyperintensities and patient characteristics, such as height, weight, and sex. METHODS Sixty-six healthy volunteers were scanned using 3.0-T PD-weighted MRI, including spectral fat suppression of the craniocervical junction. The study population was separated into 2 groups (old vs young) using 2 approaches: dichotomization at the median age (40.0 years) and the calculated threshold (28.5 years) using receiver operating characteristics (ROC). The AL was independently characterized with respect to continuity, course, shape, signal intensity, and graduation of homogeneity by 2 experienced neuroradiologists. Signal intensity was differentiated into fat-related hyperintensity and NFH. Univariate and multivariate logistic regression models were employed to investigate the relationship between patient characteristics and signal intensities. RESULTS Two different AL patterns were observed: inhomogeneous (33.3%) and homogeneous (66.7%). The latter pattern was mostly surrounded by a small dark rim (56.8%). Fat could be identified in 15.9% of all ALs (21 of 132 patients), and NFH was identified in 17.4% of all ALs (23 of 132 patients). Here, 28.5 years was the preferred threshold, demonstrating a relatively high sensitivity for dichotomizing the population based on the ROC of NFH. The most relevant factor for having NFH was being older than the calculated threshold (odds ratio [OR] 3.420, p = 0.051). Fat-related hyperintensities occurred significantly more frequently in men than women (OR 0.110 and p = 0.007 for women; OR 9.075 and p = 0.007 for men). Height was the second most significant factor: for every 1-cm increase, the odds of having fat lesions increased by approximately 10% (OR 1.102; p = 0.017). CONCLUSIONS This study shows that AL signal hyperintensities are substantially influenced by age, sex, and height in healthy individuals. Regarding fat-related hyperintensities, the most relevant factors proved to be sex and height. The odds of detecting NFH increased almost significantly after a relatively young age (> 28.5 years) and were remarkably more frequent in individuals older than 28.5 years. The authors caution presumptions equating signal alterations with age-related deterioration. Instead, they suggest that dispositional factors such as sex and height are more relevant in the AL constitution. Signal alterations in ALs naturally occur in healthy symptom-free individuals, underscoring the importance of cautiously interpreting such lesions on posttraumatic MRI scans.

Diagnostic accuracy of upper cervical spine instability tests: a systematic review

BACKGROUND

Patients with neck pain, headache, torticollis, or neurological signs should be screened carefully for upper cervical spine instability, as these conditions are "red flags" for applying physical therapy interventions. However, little is known about the diagnostic accuracy of upper cervical spine instability tests.

PURPOSE

The purpose of this study was to evaluate the diagnostic accuracy of upper cervical spine instability screening tests in patients or people who are healthy.

DATA SOURCES

PubMed, CINAHL, EMBASE, and RECAL Legacy databases were searched from their inception through October 2012.

STUDY SELECTION

Studies were included that assessed the diagnostic accuracy of upper cervical instability screening tests in patients or people who are healthy and in which sensitivity and specificity were reported or could be calculated using a 2 × 2 table.

DATA EXTRACTION AND QUALITY ASSESSMENT

Two reviewers independently performed data extraction and the methodological quality assessment using the QUADAS-2.

DATA SYNTHESIS

Depending on heterogeneity, statistical pooling was performed. All diagnostic parameters (sensitivity, specificity, predictive values, and likelihood ratios) were recalculated, if possible.

RESULTS

Five studies were included in this systematic review. Statistical pooling was not possible due to clinical and statistical heterogeneity. Specificity of 7 tests was sufficient, but sensitivity varied. Predictive values were variable. Likelihood ratios also were variable, and, in most cases, the confidence intervals were large.

LIMITATIONS

The included studies suffered from several biases. None of the studies evaluated upper cervical spine instability tests in patients receiving primary care.

CONCLUSIONS

The membranes tests had the best diagnostic accuracy, but their applicability as a test for diagnosing upper cervical spine instability in primary care has yet to be confirmed.

Are two readers more reliable than one? A study of upper neck ligament scoring on magnetic resonance images

Background

Magnetic resonance imaging (MRI) studies typically employ either a single expert or multiple readers in collaboration to evaluate (read) the image results. However, no study has examined whether evaluations from multiple readers provide more reliable results than a single reader. We examined whether consistency in image interpretation by a single expert might be equal to the consistency of combined readings, defined as independent interpretations by two readers, where cases of disagreement were reconciled by consensus.

Methods

One expert neuroradiologist and one trained radiology resident independently evaluated 102 MRIs of the upper neck. The signal intensities of the alar and transverse ligaments were scored 0, 1, 2, or 3. Disagreements were resolved by consensus. They repeated the grading process after 3–8 months (second evaluation). We used kappa statistics and intraclass correlation coefficients (ICCs) to assess agreement between the initial and second evaluations for each radiologist and for combined determinations. Disagreements on score prevalence were evaluated with McNemar’s test.

Results

Higher consistency between the initial and second evaluations was obtained with the combined readings than with individual readings for signal intensity scores of ligaments on both the right and left sides of the spine. The weighted kappa ranges were 0.65-0.71 vs. 0.48-0.62 for combined vs. individual scoring, respectively. The combined scores also showed better agreement between evaluations than individual scores for the presence of grade 2–3 signal intensities on any side in a given subject (unweighted kappa 0.69-0.74 vs. 0.52-0.63, respectively). Disagreement between the initial and second evaluations on the prevalence of grades 2–3 was less marked for combined scores than for individual scores (P ≥ 0.039 vs. P ≤ 0.004, respectively). ICCs indicated a more reliable sum score per patient for combined scores (0.74) and both readers’ average scores (0.78) than for individual scores (0.55-0.69).

Conclusions

This study was the first to provide empirical support for the principle that an additional reader can improve the reproducibility of MRI interpretations compared to one expert alone. Furthermore, even a moderately experienced second reader improved the reliability compared to a single expert reader. The implications of this for clinical work require further study.

Magnetic resonance imaging signal changes of alar and transverse ligaments not correlated with whiplash-associated disorders: a meta-analysis of case-control studies

PURPOSE

Hypothesis that loss of integrity of the membranes in the craniocervical junction might be the cause of neck pain in patients with whiplash-associated disorders (WADs) has been proposed. In recent years, with development of more detailed magnetic resonance imaging (MRI) techniques, morphologic changes of the ligaments and membranes in the craniocervical junction, especially alar and transverse ligaments have been discussed. A meta-analysis was performed to evaluate the relationship of MRI signal changes of alar and transverse ligaments and WADs.

METHODS

A systematic search of EMBASE, PUBMED, and Cochrane Library and references from eligible articles were conducted. Comparative studies reporting on evaluating the relationship between MRI high-signal changes of alar and transverse ligaments and WADs were regarded eligible. A pooled estimate of effect size was produced.

RESULTS

Alar ligaments: Six studies (total n = 622) were included. MRI signal changes of alar ligaments did not appear to be related with WADs (P = 0.20, OR = 1.54, 95 % CI = 0.80-2.94). Heterogeneity was present (I (2) = 46 %, P = 0.10), which was eliminated upon sensitivity analysis bringing the OR to 1.27 (95 % CI = 0.87-1.86, I (2) = 0 %). Transverse ligaments: Four studies (total n = 489) were included. MRI signal changes of transverse ligament did not appear to be related with WADs (P = 0.51, OR = 1.44, 95 % CI = 0.49-4.21). Heterogeneity was present (I (2) = 77 %, P = 0.005), which was eliminated upon sensitivity analysis bringing the OR to 0.79 (95 % CI = 0.49-1.28, I (2) = 0 %).

CONCLUSION

MRI signal changes of alar and transverse ligaments are not supposed to be caused by whiplash injury, and MRI examination of alar and transverse ligaments should not be used as the routine workup of patients with WADs.

Somatic symptoms beyond those generally associated with a whiplash injury are increased in self-reported chronic whiplash. A population-based cross sectional study: the Hordaland Health Study (HUSK)

BACKGROUND

Chronic whiplash leads to considerable patient suffering and substantial societal costs. There are two competing hypothesis on the etiology of chronic whiplash. The traditional organic hypothesis considers chronic whiplash and related symptoms a result of a specific injury. In opposition is the hypothesis that chronic whiplash is a functional somatic syndrome, and related symptoms a result of society-induced expectations and amplification of symptoms. According to both hypotheses, patients reporting chronic whiplash are expected to have more neck pain, headache and symptoms of anxiety and depression than the general population. Increased prevalence of somatic symptoms beyond those directly related to a whiplash neck injury is less investigated. The aim of this study was to test an implication derived from the functional hypothesis: Is the prevalence of somatic symptoms as seen in somatization disorder, beyond symptoms related to a whiplash neck injury, increased in individuals self-reporting chronic whiplash? We further aimed to explore recall bias by comparing the symptom profile displayed by individuals self-reporting chronic whiplash to that among those self-reporting a non-functional injury: fractures of the hand or wrist. We explored symptom load, etiologic origin could not be investigated in this study.

METHODS

Data from the Norwegian population-based "Hordaland Health Study" (HUSK, 1997-99); N = 13,986 was employed. Chronic whiplash was self-reported by 403 individuals and fractures by 1,746. Somatization tendency was measured using a list of 17 somatic symptoms arising from different body parts and organ systems, derived from the research criteria for somatization disorder (ICD-10, F45).

RESULTS

Chronic whiplash was associated with an increased level of all 17 somatic symptoms investigated (p<0.05). The association was moderately strong (group difference of 0.60 standard deviation), only partly accounted for by confounding. For self-reported fractures symptoms were only slightly elevated. Recent whiplash was more commonly reported than whiplash-injury a long time ago, and the association of interest weakly increased with time since whiplash (r = 0.016, p = 0.032).

CONCLUSIONS

The increased prevalence of somatic symptoms beyond symptoms expected according to the organic injury model for chronic whiplash, challenges the standard injury model for whiplash, and is indicative evidence of chronic whiplash being a functional somatic syndrome.

Are there implications for morphological changes in neck muscles after whiplash injury?

STUDY DESIGN

Literature review.

OBJECTIVE

To review the evidence related to the morphological changes (atrophy and fatty degeneration) of neck muscles in whiplash-associated disorders (WAD) and to highlight emerging evidence for the pathophysiological mechanisms behind muscle degeneration and their potential role in the transition from acute to chronic pain after whiplash injury from a motor vehicle crash (MVC).

SUMMARY OF BACKGROUND DATA

Magnetic resonance imaging (MRI) can be regarded as the gold standard for muscle imaging. There is emerging evidence to highlight in vivo features of neck muscle degeneration in patients with chronic WAD and the temporal development of such acute changes after MVC. However, the precise underlying mechanisms for such changes and their influence on functional recovery after whiplash remain largely unknown.

METHODS

Literature review of available evidence from both the authors' previous studies and other similar bodies of work.

RESULTS

Studies have quantified degenerative changes in the neck muscles of patients with acute and chronic whiplash with structural MRI applications.

CONCLUSION

Current evidence from structural MRI based studies demonstrates the widespread presence of fatty infiltrates in neck muscles of patients with chronic whiplash. Such findings have not shown to feature in patients with chronic insidious onset neck pain, suggesting traumatic factors play a role in their development. Recent studies have revealed that muscle fatty infiltrates manifest soon after whiplash but only in those with higher pain and disability and symptoms of post-traumatic stress disorder. The possibility that such muscle changes are associated with a more severe injury including poor functional recovery remains the focus of current research efforts.

The pearls and pitfalls of magnetic resonance imaging for the spine

Musculoskeletal imaging of the spine can be an invaluable tool to inform clinical decision making in patients with spinal pain. An understanding of the technology involved in producing and interpreting high-resolution images produced from magnetic resonance imaging (MRI) of the human spine is necessary to better appreciate which sequences can be used for, or tailored to, individual patients and their conditions. However, there is substantial variability in the clinical meaningfulness of some MRI findings of spinal tissues. For example, normal variants can often mimic significant musculoskeletal pathology, which could increase the risk of misinformed clinical decisions and, even worse, poor or adverse outcomes. This clinical commentary will highlight some of the pearls and pitfalls of MRI for the cervical, thoracic, and lumbar regions, and include cases to illustrate some of the common imaging artifacts and normal variants for MRI of the spine.

Follow-up MR imaging of the alar and transverse ligaments after whiplash injury: a prospective controlled study

BACKGROUND AND PURPOSE

The cause and clinical relevance of upper neck ligament high signal intensity on MR imaging in WAD are controversial. The purpose of this study was to explore changes in the signal intensity of the alar and transverse ligaments during the first year after a whiplash injury.

MATERIALS AND METHODS

Dedicated high-resolution upper neck proton attenuation-weighted MR imaging was performed on 91 patients from an inception WAD1-2 cohort, both in the acute phase and 12 months after whiplash injury, and on 52 controls (noninjured patients with chronic neck pain). Two blinded radiologists independently graded alar and transverse ligament high signal intensity 0-3, compared initial and follow-up images to assess alterations in grading, and solved any disagreement in consensus. The Fisher exact test was used to compare proportions.

RESULTS

Alar and transverse ligament grading was unchanged from the initial to the follow-up images. The only exceptions were 1 alar ligament changing from 0 to 1 and 1 ligament from 1 to 0. The prevalence of grades 2-3 high signal intensity in WAD was thus identical in the acute phase and after 12 months, and it did not differ from the prevalence in noninjured neck pain controls (alar ligaments 33.0% versus 46.2%, P = .151; transverse ligament 24.2% versus 23.1%, P = 1.000).

CONCLUSIONS

Alar and transverse ligament high signal intensity in patients with WAD1-2 observed within the first year after injury cannot be explained by the trauma. Dedicated upper neck MR imaging cannot be recommended as a routine examination in these patients.