Cervical spine meniscoids: an update on their morphological characteristics and potential clinical significance

Importance of the cervical capsular joint cartilage geometry on head and facet joint kinematics assessed in a Finite element neck model

Finite element human neck models (NMs) aim to predict neck response and injury at the tissue level; however, contemporary models are most often assessed using global response such as head kinematics. Additionally, many NMs are developed from subject-specific imaging with limited soft tissue resolution in small structures such as the facet joints in the neck. Such details may be critical to enable NMs to predict tissue-level response. In the present study, the capsular joint cartilage (CJC) geometry in a contemporary NM was enhanced (M50-CJC) based on literature data. The M50-CJC was validated at the segment and full neck levels and assessed using relative facet joint kinematics (FJK), capsular ligament (CL) and intervertebral disc (IVD) strains, a relative vertebral rotation assessment (IV-NIC) and head kinematics in frontal and rear impact. The validation ratings at the segment level increased from 0.60 to 0.64, with improvements for modes of deformation associated with the facet joints, while no difference was noted at the head kinematic level. The improved CJC led to increased FJK rotation (188%) and IVD strain (152.2%,) attributed to the reduced facet joint gap. Further enhancements of the capsular joint representation or a link between the FJK and CL injury risk are recommended. Enhancements at the tissue level demonstrated a large effect on the IVD strain, but were not apparent in global metrics such as head kinematics. This study demonstrated that a biofidelic and detailed geometrical representation of the CJC contributes significantly to the predicted joint response, which is critical to investigate neck injury risk at the tissue level.

Magnetic Resonance Imaging Investigation of Cervical-Spine Meniscoid Composition: A Validation Study

OBJECTIVE

The composition of cervical-spine meniscoids may have clinical significance in neck-pain conditions, but the accuracy of assessment of meniscoid composition in vivo using magnetic resonance imaging has not been established. The aim of this study was to compare cervical-spine meniscoid composition by magnetic resonance imaging with histologic composition.

METHODS

Four embalmed cadaveric cervical spines (mean [standard deviation] age, 79.5 [3.7] years; 1 female, 3 male) underwent magnetic resonance imaging, allowing radiologic classification of lateral atlantoaxial- and zygapophyseal-joint (C2-3 to C6-7) meniscoids as either mostly fatty, mixed tissue, or mostly connective tissue. Subsequently, each joint was dissected and disarticulated to allow excision of meniscoids for histologic processing. Each meniscoid was sectioned sagittally, stained with hematoxylin and eosin, examined using light microscopy, and classified as adipose, fibroadipose, or fibrous in composition. Data were analyzed using the kappa statistic with linear weighting.

RESULTS

From dissection, 62 meniscoids were identified, excised, and processed; 46 of these 62 were visualized with magnetic resonance imaging. For single-rater identifying structures, agreement between assessment of meniscoid composition by magnetic resonance imaging and by microscopy was fair (κ = 0.24; 95% confidence interval, 0.02-0.46; P = .02).

CONCLUSION

Findings suggest that the accuracy of this method of magnetic resonance imaging assessment of cervical-spine meniscoid composition may be limited. This should be considered when planning or interpreting research investigating meniscoid composition using magnetic resonance imaging.

Association between cervical degeneration and self-perceived nonrecovery after whiplash injury

BACKGROUND CONTEXT

Pre-existing radiological degenerative changes have not previously been considered a risk factor for nonrecovery from neck pain due to motor vehicle accidents (MVA). Results from previous studies are however often based on assessment of plain radiography or MRI and little consideration has been given to facet joints. Furthermore, previous studies have often lacked a validated scoring system for degenerative changes.

PURPOSE

To investigate the association between cervical degeneration on computed tomography (CT) and nonrecovery after whiplash trauma.

STUDY DESIGN

Longitudinal cohort study.

PATIENT SAMPLE

One hundred twenty-one patients attending the Emergency Department because of neck pain after MVA, 2015-2017, with a valid CT-scan of the cervical spine and completion of follow up after 6 months.

OUTCOME MEASURES

The primary outcome measure was self-perceived nonrecovery (yes/no) after 6 months. A secondary outcome measure was self-reported pain level (Numeric Rating Scale).

METHODS

Baseline data regarding demographics and health factors were gathered through a web-based questionnaire. Degeneration of facet joints and intervertebral discs was assessed on CT-scans according to a validated scoring system. Binary logistic regression was used to study the association between cervical degeneration and nonrecovery.

RESULTS

Moderate facet joint degeneration was associated with nonrecovery. In the group with moderate degree of facet joint degeneration, 69.6% reported nonrecovery compared with 23.6% among patients without any signs of degeneration (adjusted odds ratio 6.7 [95% confidence interval: 1.9-24.3]). There was no association between disc degeneration and nonrecovery. Combined facet joint degeneration and disc degeneration were associated with nonrecovery (adjusted odds ratio 6.2 [2.0-19.0]).

CONCLUSIONS

These results suggest that cervical degeneration, especially facet joint degeneration, is a risk factor for nonrecovery after whiplash trauma. We hypothesize that whiplash trauma can be a trigger for painful manifestation of previously asymptomatic facet joint degeneration.

Quantitative magnetic resonance imaging assessment of lateral atlantoaxial joint meniscoid composition: a validation study

PURPOSE

Lateral atlantoaxial (LAA) joint meniscoid composition may have clinical significance in patients following neck trauma. However, the existing method of radiologically assessing meniscoid composition has an inherent element of subjectivity, which could contribute to measurement variability. The present study sought to investigate the accuracy of two-point Dixon fat/water separation MRI as a quantitative assessment of LAA joint meniscoid composition.

METHODS

Sixteen LAA joint meniscoids were excised from four cadavers (mean [SD] age 79.5 [3.7] years; one female) following cervical spine MRI (two-point Dixon, T1-weighted VIBE and T2-weighted SPACE sequences). Composition of LAA joint meniscoids was undertaken by (1) histological examination by light microscopy, (2) calculation of fat fraction by Dixon MRI (both in-phase/opposed-phase and fat/water methods), and (3) the existing method of considering VIBE and SPACE signal intensities. Analysis was performed using the kappa statistic with linear weighting.

RESULTS

Microscopy revealed three, five, and eight meniscoids to be composed of adipose, fibroadipose, and fibrous tissues, respectively. Dixon sequence MRI classified 11 of these meniscoids correctly, with 'substantial' level of agreement (In-phase/Opp-phase kappa statistic = 0.78 [95% CI 0.38, 1.17]; fat/water kappa statistic = 0.72 [95% CI 0.32, 1.11]). Level of agreement between microscopy and the VIBE and SPACE method was 'slight' (kappa statistic = 0.02 [95% CI - 0.34, 0.38]).

CONCLUSIONS

Findings suggest that Dixon fat/water separation MRI may have superior utility in the assessment of LAA joint meniscoid composition than the existing method of considering VIBE and SPACE signal intensities. These slides can be retrieved under Electronic Supplementary Material.

Towards defining muscular regions of interest from axial magnetic resonance imaging with anatomical cross-reference: part II - cervical spine musculature

Background

It has been suggested that the quantification of paravertebral muscle composition and morphology (e.g. size/shape/structure) with magnetic resonance imaging (MRI) has diagnostic, prognostic, and therapeutic potential in contributing to overall musculoskeletal health. If this is to be realised, then consensus towards standardised MRI methods for measuring muscular size/shape/structure are crucial to allow the translation of such measurements towards management of, and hopefully improved health for, those with some musculoskeletal conditions. Following on from an original paper detailing methods for measuring muscles traversing the lumbar spine, we propose new methods based on anatomical cross-reference that strive towards standardising MRI-based quantification of anterior and posterior cervical spine muscle composition.

Methods

In this descriptive technical advance paper we expand our methods from the lumbar spine by providing a detailed examination of regional cervical spine muscle morphology, followed by a comprehensive description of the proposed technique defining muscle ROI from axial MRI. Cross-referencing cervical musculature and vertebral anatomy includes an innovative comparison between axial E12 sheet-plastinates derived from cadaveric material to a series of axial MRIs detailing commonly used sequences. These images are shown at different cervical levels to illustrate differences in regional morphology. The method for defining ROI for both anterior (scalenes group, sternocleidomastoid, longus colli, longus capitis) and posterior (multifidus, semispinalis cervicis, semispinalis capitis, splenius capitis) cervical muscles is then described and discussed in relation to existing literature.

Results

A series of steps towards standardising the quantification of cervical spine muscle quality are described, with concentration on the measurement of muscle volume and fatty infiltration (MFI). We offer recommendations for imaging parameters that should additionally inform a priori decisions when planning investigations of cervical muscle tissues with MRI.

Conclusions

The proposed method provides an option rather than a final position for quantifying cervical spine muscle composition and morphology using MRI. We intend to stimulate discussion towards establishing measurement consensus whereby data-pooling and meaningful comparisons between imaging studies (primarily MRI) investigating cervical muscle quality becomes available and the norm.

Lateral atlantoaxial joint meniscoid volume in individuals with whiplash associated disorder: A case-control study

BACKGROUND

Lateral atlantoaxial (LAA) joints are established sources of nociceptive input in chronic whiplash associated disorder (WAD). These joints contain intra-articular meniscoids that may be damaged in whiplash trauma. LAA joint meniscoid morphology has not been investigated comprehensively in a chronic WAD population, and it is unclear whether morphological differences exist compared to a pain-free population.

OBJECTIVES

This study examined LAA joint meniscoid volume in individuals with chronic WAD who report pain in a distribution consistent with LAA joint pain.

DESIGN

Case-control study.

METHOD

Fourteen individuals with chronic WAD with pain in an LAA joint distribution (mean [SD] age 38.1 [10.8] years; six female) and 14 age- and sex-matched pain-free controls (38.0 [10.5] years) underwent cervical spine magnetic resonance imaging. LAA joint images were inspected for meniscoids; meniscoid volume was calculated in mm³ and as a percentage of articular cavity volume. Symptom duration, location and intensity were recorded. Data were analysed using paired t-tests, Wilcoxon signed-rank testing, Spearman's rank testing, linear and logistic regression (α < 0.05).

RESULTS

Ventral and dorsal meniscoids (n = 112) were found in each LAA joint. Greater dorsal meniscoid volume as a percentage of articular cavity volume was associated with higher pain intensity (odds ratio 1.48, p = 0.03; likelihood ratio test chi-square₂ = 6.64, p = 0.04), however no significant differences existed between meniscoid volumes of WAD and control participants.

CONCLUSIONS

Findings indicate a potential link between dorsal LAA joint meniscoid volume and pain, suggesting larger meniscoid size may have pathoanatomical significance in WAD.