High-field magnetic resonance imaging of meniscoids in the zygapophyseal joints of the human cervical spine

Immunohistochemical investigation of nerve fiber presence and morphology in elderly cervical spine meniscoids

BACKGROUND CONTEXT

Innervation of anatomical structures is fundamental to their capacity to generate nociceptive impulses. Cervical spine meniscoids are hypothesized to be contributors to neck pain; however, their innervation is not comprehensively understood.

PURPOSE

This study aimed to examine the presence and morphology of nerve fibers within cervical spine meniscoids and adjacent joint capsules.

STUDY DESIGN

This is a cross-sectional study.

PATIENT SAMPLE

The sample consists of cervical hemispines of 12 embalmed cadavers (mean [standard deviation] age 82.9 [6.5] years, six female, six left). Either the right or the left half of the cervical spine (hemispine) of each cadaver was included in the sample. So six left sides and six right sides of the cadaver cervical spines made up the 12 hemispines that formed the sample.

METHODS

Cervical spine meniscoids and adjacent joint capsules were excised from lateral atlantoaxial and cervical zygapophyseal (C2-C3 to C6-C7) joints (n=67), then paraffin embedded. Meniscoids were sectioned sagittally (5 µm), slide mounted, and immunohistochemistry was performed using primary antibodies to neurofilament heavy (NF-H) and pan-neurofilament (Pan-NF) to identify nerve tissue. The study was supported by institutional graduate student funding. The authors have no conflicts of interest to declare.

RESULTS

Seventy-seven meniscoids (23 lateral atlantoaxial, 54 cervical zygapophyseal) were extracted and processed (154 sections in total). Sixty-four individual nerve fiber bundles were identified (26 NF-H positive, 38 Pan-NF positive) from 14 meniscoids. Nerves immunoreactive to both NF-H and Pan-NF were identified in 13 of 77 meniscoids (10 of 14 lateral atlantoaxial joint) from 11 joints (eight cadavers). Nerves were always located in joint capsules except three exclusively Pan-NF immunoreactive nerve fiber bundles from two adipose meniscoids.

CONCLUSIONS

The low nerve prevalence in elderly cervical spine meniscoids, with nerves only found in two adipose type meniscoids, suggests these structures may play a minimal role in cervical nociception generation in this demographic. The joint capsules, which were more frequently innervated, appear to be more likely generators of nociception in the elderly. Joint capsule nerves were mostly NF-H positive, indicating potential Aδ-fiber presence.

Morphology and morphometry of lateral atlantoaxial joint meniscoids

The lateral atlantoaxial joints contain folds of synovium termed meniscoids that may potentially contribute to cervical spine pain; however, the anatomy of these structures has not been comprehensively investigated. The purpose of this study was to explore the morphology and morphometry of lateral atlantoaxial joint meniscoids. Twelve cadaveric hemi-spines (6 female; 6 left; mean 81.5 years, SD 7.3) were obtained for dissection and disarticulation of the lateral atlantoaxial joints. Meniscoids were identified and measurements made of surface area, length, and surrounding articular cartilage degeneration. Tissue was sectioned sagittally, stained with hematoxylin and eosin, and examined by light microscopy. Data were analyzed descriptively and using nonparametric techniques. Ventral and dorsal meniscoids (24 in total) were found in each joint, and could be classified histologically into adipose (32%), fibrous (41%), and fibroadipose (27%) meniscoids. No significant associations were found between meniscoid size and age, histology, cartilage degeneration, or joint position. Meniscoid length in males was significantly greater than in females (P = 0.04). Fibrous meniscoids were noted to be associated with articular cartilage degeneration, and adipose and fibroadipose meniscoids with intact cartilage (P = 0.05). Fibrous meniscoids tended to be located dorsally (78%), whereas adipose meniscoids were mostly located ventrally (86%). Distinct patterns in lateral atlantoaxial joint meniscoid morphology were observed, including the association of fibrous meniscoid composition with dorsal joint position and articular cartilage degeneration. The clinical significance of these patterns remains uncertain, and further research is needed to examine these structures across the lifespan and in cervical pathology.

The equine cervical spine: comparing MRI and contrast-enhanced CT images with anatomic slices in the sagittal, dorsal, and transverse plane

BACKGROUND

The impact of cervical pathology on performance is of great importance to the horse industry. Accurate diagnosis of cervical disease with imaging modalities, including computed tomography (CT) and magnetic resonance imaging (MRI), requires thorough appreciation of normal cervical anatomy.

OBJECTIVES

(1) To describe in detail the anatomy of the equine cervical spine by comparing anatomical sections with corresponding MR and contrast-enhanced CT images in the sagittal, dorsal, and transverse plane. (2) To discuss the ability of MR and contrast-enhanced CT imaging to visualize anatomical structures in the cervical spine.

ANIMALS AND METHODS

Three cervical spines of young adults (3-8 years), collected immediately after humane euthanasia, were used. The spine was stabilized on a frame in a natural flexed position with an angle of 20°. MR and contrast-enhanced CT imaging was performed within six hours after euthanasia. Anatomical sections of 1 cm were made in the sagittal, dorsal, and transverse plane and compared with corresponding CT and MR images. The intervertebral disk thickness, facet joint angle, sagittal dural space diameter and ventromedial facet joint projection were quantified.

RESULTS

The anatomic location of clinically important structures including the facet joints, spinal cord, cervical nerve roots and intervertebral disks were reliably identified in the anatomical sections and their corresponding MR images. Contrast-enhanced CT images depicted all osseous borders, whereas MR images were superior for soft tissue structures.

CONCLUSION AND CLINICAL IMPORTANCE

This study enhances our understanding of normal cervical spine anatomy and the diagnostic usefulness of cervical MRI and contrast-enhanced CT in the horse.

Development of a clinical prediction rule to identify patients with neck pain likely to benefit from thrust joint manipulation to the cervical spine

STUDY DESIGN

Prospective cohort/predictive validity study.

OBJECTIVE

To determine the predictive validity of selected clinical examination items and to develop a clinical prediction rule to determine which patients with neck pain may benefit from cervical thrust joint manipulation (TJM) and exercise.

BACKGROUND

TJM to the cervical spine has been shown to be effective in patients presenting with a primary report of neck pain. It would be useful for clinicians to have a decision-making tool, such as a clinical prediction rule, that could accurately identify which subgroup of patients would respond positively to cervical TJM.

METHODS

Consecutive patients who presented to physical therapy with a primary complaint of neck pain completed a series of self-report measures, then received a detailed standardized history and physical examination. After the clinical examination, all patients received a standardized treatment regimen consisting of cervical TJM and range-of-motion exercise. Depending on response to treatment, patients were treated for 1 or 2 sessions over approximately 1 week. At the end of their participation in the study, patients were classified as having experienced a successful outcome based on a score of +5 ("quite a bit better") or higher on the global rating of change scale. Sensitivity, specificity, and positive and negative likelihood ratios were calculated for all potential predictor variables. Univariate techniques and stepwise logistic regression were used to determine the most parsimonious set of variables for prediction of treatment success. Variables retained in the regression model were used to develop a multivariate clinical prediction rule.

RESULTS

Eighty-two patients were included in data analysis, of whom 32 (39%) achieved a successful outcome. A clinical prediction rule with 4 attributes (symptom duration less than 38 days, positive expectation that manipulation will help, side-to-side difference in cervical rotation range of motion of 10° or greater, and pain with posteroanterior spring testing of the middle cervical spine) was identified. If 3 or more of the 4 attributes (positive likelihood ratio of 13.5) were present, the probability of experiencing a successful outcome improved from 39% to 90%.

CONCLUSION

The clinical prediction rule may improve decision making by providing the ability to a priori identify patients with neck pain who are likely to benefit from cervical TJM and range-of-motion exercise. However, this is only the first step in the process of developing and testing a clinical prediction rule, as future studies are necessary to validate the results and should include long-term follow-up and a comparison group.

LEVEL OF EVIDENCE

Prognosis, level 2b.

Morphometry of the synovial folds of the lateral atlanto-axial joints: the anatomical basis for understanding their potential role in neck pain

PURPOSE

Intra-articular synovial folds of the cervical spine are considered to be a potential source of neck pain and disability. The purpose of the present study was to devise and validate a method to determine the normal morphometry of the synovial folds as a basis for understanding their functional and clinical significance.

METHODS

Nine cadaver cervical spines were sectioned in the sagittal plane. The presence of the synovial folds at the lateral atlanto-axial joints was determined and their morphology described. Depth of projection, cross-sectional area and volume of the ventral and dorsal synovial folds of the right and left lateral atlanto-axial joints were measured from sagittal sections and compared. The relationship between synovial fold dimensions and subject age and cartilage degeneration were determined. Repeat measurements were made for the calculation of method reliability, and the water displacement method was used to determine method validity.

RESULTS

There was a trend for ventral synovial folds to be larger than dorsal synovial folds. There was no correlation between synovial fold dimensions and age and extent of cartilage degeneration. Measurement reliability ranged from intraclass correlation coefficient 0.95-1.00 (intra-observer), 0.95-1.00 (test-retest) and 0.61-1.00 (inter-observer). Limits of agreement for the sectional and water displacement methods for the measurement of synovial fold volume were -1.04 ± 3.35 mm(3).

CONCLUSIONS

A reliable method for quantifying synovial fold dimensions was devised. The results of this study provide a basis for the determination and diagnosis of pathologies affecting the synovial folds.

Synovial folds - a pain in the neck?

The synovial folds of the cervical spine are regarded as a potential source of neck pain and headache, especially following whiplash injury. Damage to the synovial folds following motor vehicle trauma has been well documented in post-mortem studies. However, methods of identifying injury to the synovial folds in the survivors of motor vehicle trauma have proven elusive to date. Recently, it has been made possible to image the synovial folds in vivo using magnetic resonance imaging. This now makes it feasible to investigate the potential involvement of synovial folds in the generation of neck pain and headache and its relief using spinal manipulation. This paper reviews critically the morphology of the synovial folds of the cervical spine that underpins the hypotheses proposed to explain their functional and clinical significance and a new system of naming and classifying the synovial folds is presented. Although there is some evidence to support the contribution of the synovial folds to neck pain, several theories have little or no support and require investigation and further evaluation. These findings have implications for understanding the anatomical basis of neck pain and headache and the rationale for the use of spinal manipulation in their management.

Autologous chondrocyte implantation in cartilage lesions of the knee: long-term evaluation with magnetic resonance imaging and delayed gadolinium-enhanced magnetic resonance imaging technique

BACKGROUND

Various treatment options are available for articular cartilage lesions, but controversy exists regarding the quality of the repair tissue and the durability of the results posttreatment. Noninvasive techniques are needed for the assessment of the repair tissue.

HYPOTHESIS

Magnetic resonance imaging (MRI) with delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) can give valuable information regarding the quality and quantity of the repaired cartilage lesion.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Thirty-six knees in 31 patients were assessed 9 to 18 years after treatment with autologous chondrocyte implantation (ACI). All patients had isolated lesions. The knees were clinically evaluated with the Knee injury and Osteoarthritis Outcome Score and the dGEMRIC technique. The T1 value was measured for 2 regions of interest (ROIs), 1 in the repair tissue area (ROI 1) and 1 in the surrounding cartilage (ROI 2), giving information of the content of proteoglycans.

RESULTS

The average T1 value in ROI 1 was 467.5 milliseconds and in ROI 2, 495.3 milliseconds, which yielded no significant difference, thus suggesting comparable levels of proteoglycans in the repair tissue and surrounding cartilage. Intralesional osteophytes were in 64% of the lesions, mainly in younger patients with osteochondritis dissecans lesions or a history of subchondral bone surgeries. Medium or large bone marrow edema was found in 14% of the knees and subchondral cysts, in 39%. There was no correlation between the KOOS and any MRI findings.

CONCLUSION

Magnetic resonance imaging with dGEMRIC gives valuable information for the macroscopic appearance and micro-molecular quality of the repair tissue after ACI. Nine to 18 years posttreatment, the quality of the repair tissue is similar to the surrounding normal cartilage, although intralesional osteophytes, subchondral cysts, and bone marrow edema were common. The defect area is restored in most patients. However, there was no correlation between the dGEMRIC values and the KOOS outcomes.

Synovial folds of the lateral atlantoaxial joints: in vivo quantitative assessment using magnetic resonance imaging in healthy volunteers

STUDY DESIGN

Analysis of magnetic resonance (MR) images of healthy volunteers.

OBJECTIVE

To develop and validate an imaging protocol and measurement technique to describe the morphology and quantify the dimensions of the synovial folds of the lateral atlantoaxial joints in vivo.

SUMMARY OF BACKGROUND DATA

The synovial folds of the lateral atlantoaxial joints are considered to be a potential source of neck pain and headache, especially following whiplash injury. Until recently, it has not been possible to image the synovial folds in vivo and consequently their normal morphology is not fully understood.

METHODS

MR images of the cervical spine of 17 volunteers (4 male and 13 female) were acquired using a 1.5-tesla scanner. The morphology of the synovial folds at the lateral atlantoaxial joints was described and their presence determined. The volume and cross-sectional area of the ventral and dorsal synovial folds of the right and left lateral atlantoaxial joints were measured and compared. The relationship between the dimensions of the synovial folds and subject age was examined. Twenty synovial folds were measured twice by one observer and once by a second observer for the determination of measurement reliability.

RESULTS

There was a significant difference in volume (chi [3] = 17.54, P = 0.000) and cross-sectional area (chi [3] = 18.95, P = 0.000) between the ventral and dorsal synovial folds of the left and right lateral atlantoaxial joints. There was no correlation between synovial fold dimensions and age. The reliability of the measurements ranged from intraclass correlation coefficient 0.95 to 0.99 (intraobserver reliability) and intraclass correlation coefficients 0.75 to 0.82 (interobserver reliability).

CONCLUSION

MR imaging was successfully implemented as a noninvasive method for visualizing the synovial folds of the lateral atlantoaxial joints and quantifying their dimensions in healthy volunteers. The results of this study provide a basis for future studies investigating synovial fold pathology in patients with neck pain and headache.

Reference data for in vivo magnetic resonance imaging properties of meniscoids in the cervical zygapophyseal joints

STUDY DESIGN

Prospective in vivo study of meniscoids in the cervical zygapophyseal joints.

OBJECTIVE

To generate reference data for in vivo magnetic resonance (MR) imaging properties of meniscoids in the cervical zygapophyseal joints.

SUMMARY OF BACKGROUND DATA

Meniscoids, also called synovial folds, are tiny anatomic structures within the zygapophyseal joints. It has been suggested that pathologic conditions of meniscoids may be a potential source of cervical pain. Prior studies were limited to in vitro observations. To identify pathologic conditions of the meniscoids, it is necessary to obtain reference data of basic in vivo MR imaging properties of meniscoids in a healthy population.

METHODS

Fifty-six healthy volunteers (33 women, 23 men; mean age 42.0 +/- 17.1 years) were investigated in a 3.0 Tesla MR scanner using high resolution isotropic 3-dimensional sequences. Presence, size, location, and signal intensity of the meniscoids were assessed, and their dependence on sex, age, body mass index, and degenerative changes were analyzed by t test and correlation analysis.

RESULTS

There was no significant difference in presence (20.3 +/- 4.8 vs. 19.7 +/- 4.8) and size (3.8 +/- 0.7 mm vs. 4.1 +/- 0.5 mm) of meniscoids between women and men. Presence of meniscoids decreased with increasing age (r = -0.38, P = 0.004). Size of meniscoids did not significantly depend on age (r = 0.02, P = 0.91). Meniscoid entrapment (location) was a rare condition (0.4%). Tissue composition (signal intensities) of the meniscoids was 61.6% mainly fatty, 15.8% mainly fibrous, and 22.6% mixed.

CONCLUSION

Basic data about in vivo MR imaging properties of cervical meniscoids in a healthy population have been successfully generated. Subsequent studies may use these data as reference for the identification of meniscoid pathologies.

Diffusion weighted imaging in osteoradiology

Diffusion weighted imaging gained attention as an imaging modality, which provides information on the microstructure of a tissue, which can be used for tissue characterization. This is of importance in patients where other diagnostic tools provide equivocal or unspecific information. In addition quantitative diffusion measurements provide objective parameters for unbiased comparison of treatment response, which is mandatory for therapy monitoring. Technical restriction limited the use of Diffusion Weighted Imaging to the brain. However, with the improvement in scanner technology and the availability of new MR sequences investigation of the Muskulo Skeletal System was made possible. We describe the potential of Diffusion Weighted Imaging as a non-invasive technique to evaluate pathological, inflammatory and physiological processes in osteoradiology.