Quantitative changes in the cervical neural foramen resulting from axial traction: in vivo imaging study

MRI evaluation of foraminal changes in the cervical spine with assistance of a novel compression device

Standard supine Magnetic Resonance Imaging (MRI) does not acquire images in a position where most patients with intermittent arm radiculopathy have symptoms. The aim of this study was to test the feasibility of a new compression device and to evaluate image quality and foraminal properties during a Spurling test under MRI acquisition. Ten asymptomatic individuals were included in the study (6 men and 4 women; age range 27 to 55 years). First, the subjects were positioned in the cervical compression device in a 3 T MRI scanner, and a volume T2 weighted (T2w) sequence was acquired in a relaxed supine position (3 min). Thereafter, the position and compressive forces on the patient's neck (provocation position) were changed by maneuvering the device from the control room, with the aim to simulate a Spurling test, causing a mild foraminal compression, followed by a repeated image acquisition (3 min). A radiologist measured the blinded investigations evaluating cervical lordosis (C3-C7), foraminal area on oblique sagittal images and foraminal cross-distance in the axial plane. A total of three levels (C4-C7) were measured on the right side on each individual. Measurements were compared between the compressed and relaxed state. Reliability tests for inter- and intraclass correlation were performed. The device was feasible to use and well tolerated by all investigated individuals. Images of adequate quality was obtained in all patients. A significant increase (mean 9.4, p = 0.013) in the cervical lordosis and a decreased foraminal cross-distance (mean 32%, p < 0.001) was found, during the simulated Spurling test. The area change on oblique sagittal images did not reach a statistically significant change. The reliability tests on the quantitative measures demonstrated excellent intraobserver reliability and moderate to good interobserver reliability. Applying an individualized provocation test on the cervical spine, which simulates a Spurling test, during MRI acquisition was feasible with the novel device and provided images of satisfactory quality. MRI images acquired with and without compression showed changes in cervical lordosis and foraminal cross distance indicating the possibility of detecting changes of the foraminal properties. As a next step, the method is to be tested on symptomatic patients.

Cervical disc degeneration: important considerations for the manual therapist

Cervical disc degeneration (CDD) is a progressive, age-related occurrence that is frequently associated with neck pain and radiculopathy. Consistent with the majority of published clinical practice guidelines (CPG) for neck pain, the 2017 American Physical Therapy Association Neck Pain CPG recommends cervical manipulation as an intervention to address acute, subacute, and chronic symptoms in the 'Neck Pain With Mobility Deficits' category as well for individuals with 'Chronic Neck Pain With Radiating Pain'. While CPGs are evidence-informed statements intended to help optimize care while considering the relative risks and benefits, these guidelines generally do not discuss the mechanical consequences of underlying cervical pathology nor do they recommend specific manipulation techniques, with selection left to the practitioner's discretion. From a biomechanical perspective, disc degeneration represents the loss of structural integrity/failure of the intervertebral disc. The sequelae of CDD include posterior neck pain, segmental hypermobility/instability, radicular symptoms, myelopathic disturbance, and potential vascular compromise. In this narrative review, we consider the mechanical, neurological, and vascular consequences of CDD, including information on the anatomy of the cervical disc and the mechanics of discogenic instability, the anatomic and mechanical basis of radiculitis, radiculopathy, changes to the intervertebral foramen, the importance of Modic changes, and the effect of spondylotic hypertrophy on the central spinal canal, spinal cord, and vertebral artery. The pathoanatomical and biomechanical consequences of CDD are discussed, along with suggestions which may enhance patient safety.

Effect of a Traction Exercise Neck Brace on Cervical Spondylopathy Radiculopathy: A Clinical Study and Finite Element Analysis

Traction of cervical spine is an effective method for the treatment of cervical spondylotic radiculopathy (CSR). In this study, a cervical tractor named traction exercise neck brace (TENB) was used to evaluate its effect on the patients with CSR. Forty CSR volunteers were recruited and randomly divided into two groups. One group was subjected to cervical muscle exercise with TENB under static traction condition. Another group was subjected to (JOBT) as controls. Symptoms of CSR were evaluated by the visual analogue scale (VAS) and neck disability index (NDI). Imaging characteristics were assessed by curvature of the cervical spine and size of the intervertebral foramen. A finite element (FE) analysis model of cervical spine was established by 3D reconstruction to simulate the TENB traction, which evaluates the biomechanical performance. Results showed that TENB significantly reduced scores of VAS and NDI in subjects, and this improved effect on symptoms of pain and radiculopathy is better than that of JOBT. TENB also improved the cervical curvature and enlarged intervertebral foramen at the C4-C6 level. Moreover, FE analysis found that simulated TENB traction increased the spacing of intervertebral foramen, intervertebral disc, and zygapophyseal and uncovertebral joints and changed the stress distribution on the facet joints and nucleus pulposus. This study demonstrates that TENB relieves the symptoms of CSR by adjusting structure of cervical vertebra and restoring its biomechanical performance, which may be a promising instrument in the treatment of CSR.

Morphometric changes of the cervical intervertebral foramen: A comparative analysis of pre-manipulative positioning and physiological axial rotation

BACKGROUND

Cervical foraminal impingement has been described as a source of radicular pain. Clinical tests and head motions have been reported for affecting the intervertebral foramen (IVF) dimensions. Although manual approaches are proposed in the management of cervical radiculopathy, their influence on the foraminal dimensions remains unclear.

OBJECTIVES

To investigate the influence of pre-manipulative positioning versus cervical axial rotation on the foraminal dimensions of the lower cervical spine.

METHODS

Thirty asymptomatic volunteers underwent CT scan imaging in neutral position and axial rotation or pre-manipulative positioning. The manipulation task was performed at C4-C5 following a multiple components procedure. 3D kinematics and IVF (height, width and area) were computed for each cervical segment.

RESULTS

The results showed that foraminal changes are dependent on motion types and cervical levels. With reference to head rotation, IVF opening occurred on the ipsilateral side during pre-manipulative positioning while axial rotation involved the contralateral side. Regardless of the side considered, magnitudes of opening were similar between both attitudes while narrowing was lower at the target and adjacent levels during the pre-manipulative positioning. Some associations between segmental motion and IVF changes were observed for the target level and the overlying level.

CONCLUSIONS

The present study demonstrated that pre-manipulative positioning targeting C4-C5 modified IVF dimensions differently than the passive axial rotation. The findings suggest that techniques which incorporate combined movement positioning influence segmental motion and IVF dimensions differently at the target segment, compared to unconstrained rotation. Further investigations are needed to determine the clinical outcomes of such an approach.

Cervical traction therapy with and without neck support: A finite element analysis

BACKGROUND

Cervical traction is commonly used for treating neck pain. However, few studies have investigated the biomechanical impact such traction has on soft tissues.

OBJECTIVES

To analyze the biomechanics of cervical traction therapy in a supine position with and without neck support (NS and non-NS).

METHODS

A finite element model of the cervical spine was constructed to investigate the mechanism behind cervical traction therapy. An axial traction force of 100-N was loaded on the upper surface of C0 to simulate traction weight. Neck support traction was simulated by additionally constraining anterior-posterior motion of the surface of the C4 vertebral lamina. The average von Mises stress, tensile force and motions of related tissues were calculated and compared between the two conditions. Stress in the posterior annulus fibers under flexion was also recorded for comparison.

RESULTS

At the C4-C5 and C5-C6 levels, NS traction resulted in less of a decrease in the lordotic angle. At these levels, the highest average stress was distributed in the posterior annulus fibers with non-NS traction and both traction therapies produced greater stress on the posterior annulus fibers than physical flexion. The intradiscal pressure in all intervertebral discs between C4-T1 decreased during both traction therapies.

CONCLUSION

Neck support traction therapy produced less tension on the posterior annulus fibers and ligaments posterior to it at the C4-C5 and C5-C6 levels. In order to minimize the potential harm to soft tissue in clinical practice, it may be beneficial to use a neck support according to the targeted level.

Multimodal treatment program comparing 2 different traction approaches for patients with discogenic cervical radiculopathy: a randomized controlled trial

OBJECTIVE

The purpose of this study was to investigate the immediate and long-term effects of a 1-year multimodal program with the addition of 2 different traction approaches on the pain, function, disability, and nerve root function in patients with discogenic cervical radiculopathy (CR). This study also attempted to identify the optimal traction angle based on the maximum recovery of the peak-to-peak amplitude of the flexor carpi radialis (FCR) H-reflex.

METHODS

This randomized clinical trial with one-year follow-up included a total of 216 (101 female) patients with unilateral lower discogenic CR were randomly assigned to 1 of 3 groups. The standard care group (C) received the multimodal program (pain relief methods, muscle strengthening, and thoracic spine manipulation). The ventroflexion traction group (A) received the same multimodal program as group C, with added traditional ventroflexion traction. The novel traction group (B) received the same multimodal program as group C in addition to a flexor carpi radialis (FCR) H-reflex-based traction method. Primary outcomes were the Neck Disability Index (NDI) and secondary outcomes included neck pain, arm pain, and the amplitude and latency of the H-reflex. Patients were assessed at 3 intervals (pre-treatment, 4 weeks post-treatment, and the 1-year follow-up).

RESULTS

The mixed linear model with repeated measures indicated a significant group × time effect in favor of the novel cervical traction group (B) for measures of NDI (F = 412.6, P < .0005), neck pain (F = 108.9, P < .0005), arm pain (F = 91.3, P < .0005), H- reflex amplitude (F = 207.7, P < .0005), and H-reflex latency (F = 58.9 P < .0005). We found that the extension position of cervical spine (5° extension) was the position that achieved the maximum improvement in the novel cervical traction method.

CONCLUSIONS

This preliminary study showed that a multimodal program with a novel cervical traction method added improved NDI, neck pain, arm pain, and the amplitude and latency of FCR H-reflex for a group of patients with chronic discogenic CR.

Intradiscal Pressure Changes during Manual Cervical Distraction: A Cadaveric Study

The objective of this study was to measure intradiscal pressure (IDP) changes in the lower cervical spine during a manual cervical distraction (MCD) procedure. Incisions were made anteriorly, and pressure transducers were inserted into each nucleus at lower cervical discs. Four skilled doctors of chiropractic (DCs) performed MCD procedure on nine specimens in prone position with contacts at C5 or at C6 vertebrae with the headpiece in different positions. IDP changes, traction forces, and manually applied posterior-to-anterior forces were analyzed using descriptive statistics. IDP decreases were observed during MCD procedure at all lower cervical levels C4-C5, C5-C6, and C6-C7. The mean IDP decreases were as high as 168.7 KPa. Mean traction forces were as high as 119.2 N. Posterior-to-anterior forces applied during manual traction were as high as 82.6 N. Intraclinician reliability for IDP decrease was high for all four DCs. While two DCs had high intraclinician reliability for applied traction force, the other two DCs demonstrated only moderate reliability. IDP decreases were greatest during moving flexion and traction. They were progressevely less pronouced with neutral traction, fixed flexion and traction, and generalized traction.

Automated measurement of neural foramen cross-sectional area during in vivo functional movement

An automated technique to measure neural foramen cross-sectional area during in vivo, multi-planar movements is presented. This method combines three-dimensional (3D) models of each vertebra obtained from CT scans with in vivo movement data collected using high-speed biplane radiography. A novel computer algorithm that automatically traces a path around the bony boundary that defines the neural foramen at every frame of X-ray data is described. After identifying the neural foramen boundary, the cross-sectional area is calculated. The technique is demonstrated using data collected from a patient with cervical radiculopathy who is tested before and after conservative treatment. The technique presented here can be applied when 3D, dynamic, functional movements are performed. Neural foramen cross-sectional area can be quantified at specific angles of intervertebral rotation, allowing for matched comparisons between two trials or two test sessions. The present technique is ideal for longitudinal studies involving subjects who receive conservative or surgical treatments that may affect spine motion.

A randomized controlled trial on the efficacy of intermittent cervical traction for patients with chronic neck pain

Objective: To investigate the efficacy of intermittent cervical traction in the treatment of chronic neck pain over a 12-week follow-up.

Design: A randomized controlled trial.

Setting: Hospital-based outpatient practice.

Subjects: Seventy-nine patients with chronic neck pain.

Interventions: Subjects were randomly assigned to either experimental group ( n = 39, mean age = 50.5 ± 9.8) or control group ( n = 40, mean age = 48.8 ± 9.1). Experimental group received intermittent cervical traction and control group received infrared irradiation alone; twice a week over a period of six weeks.

Outcome measurements: The values of Chinese version of the Northwick Park Neck Pain Questionnaire (NPQ), verbal numerical pain scale (VNPS), and cervical active range of motion (AROM) were measured at baseline, six-week and 12-week follow-up.

Results: No significant differences were found between the two groups in the NPQ ( P > 0.05), VNPS ( P > 0.05) and AROM ( P > 0.05).

Efeito da tração manual sobre o comprimento da coluna cervical em indivíduos assintomáticos: estudo randomizado controlado

Os objetivos do estudo foram o de mensurar o comprimento da coluna cervical quando submetida à tração manual, e o de verificar as alterações da cervical após um período de 10 sessões consecutivas. Trata-se de estudo randomizado controlado, no qual 64 participantes foram submetidos a dois procedimentos radiológicos, antes e durante a tração. As distâncias das bordas anteriores e posteriores do corpo vertebral C2 até as do corpo vertebral de C7 foram mensuradas e comparadas. Na primeira etapa as medidas das bordas anteriores foi de 8,40 para 8,50 cm (P<0,001) e nas posteriores foi de 8,35 para 8,50 cm (P<0,001). Para a segunda etapa, os indivíduos foram aleatorizados em grupo controle (n=31) e intervenção (n=33), o qual recebeu dez sessões tração cervical. Após as sessões, as distâncias anterior e posterior do grupo intervenção aumentaram significativamente de 8,40 para 8,90 cm (P<0,001) e de 8,40 para 8,65 cm (P<0,001), respectivamente. Após as trações, todos os participantes repetiram os mesmos procedimentos radiológicos, as mensurações e as comparações das distâncias vertebrais. Quando os dois grupos foram comparados após as trações, houve diferença estatisticamente significante entre as distâncias anteriores e posteriores, de 8,20 e 8,90 cm (P=0,015) e de 8,30 e 8,65cm (P=0,030), respectivamente. Portanto, a tração aumentou o comprimento da coluna cervical. Após um período de aplicação das sessões, ocorreu aumento significativo das medidas entre as vértebras.

Enhanced external counterpulsation and traction therapy ameliorates rotational vertebral artery flow insufficiency resulting from cervical spondylosis

STUDY DESIGN

Clinical trial of patients with rotational vertebrobasilar insufficiency (VBI) resulting from cervical spondylosis.

OBJECTIVE

To investigate the effectiveness of enhanced external counterpulsation (EECP) and traction therapy for these patients.

SUMMARY OF BACKGROUND DATA

EECP would reduce arterial stiffness and vascular resistance, and increase regional blood flow of vertebral arteries, thus may ameliorate symptoms in these patients.

METHODS

One hundred sixty-three patients who were clinically suspected rotational VBI caused by cervical spondylosis were enrolled in this study. They were randomly allocated into 3 groups: EECP + traction, EECP, and traction group. All patients and 50 healthy volunteers received transcranial color Doppler examination of the vertebral artery and basilar artery in both a neutral cervical spine position and a rotational position.

RESULTS

Within 3 days after treatment, 47 (84%) patients in EECP + traction group, 32 (61%) patients in EECP group, and 8 (15%) patients in traction group achieved successful outcomes, while at 3 months' follow-up, 45 (80%) patients in EECP + traction group, 34 (64%) in EECP group, and 3 (6%) in traction group achieved successful outcomes. With head rotation, the percentage of reduction of blood flow velocities of the vertebrobasilar artery (VBA) in patients was much greater than that of the healthy volunteers (P < 0.01). After treatment, rotational blood flow velocity reduction percentage of VBA in each treatment group was much lower than that of each group before treatment. EECP + traction group experienced the greatest decrease of rotational blood flow velocity reduction percentage of VBA, while EECP group experienced second greatest.

CONCLUSION

EECP and traction therapy can relieve the symptoms of rotational VBI, improve the rotational reduction of vertebrobasilar blood flow, and reduce the increased arterial impedance.

The value of intermittent cervical traction in recent cervical radiculopathy

OBJECTIVE

Our objective is to assess the effect of mechanical and manual intermittent cervical traction on pain, use of analgesics and disability during the recent cervical radiculopathy (CR).

METHODS

We made a prospective randomized study including patients sent for rehabilitation between April 2005 and October 2006. Thirty-nine patients were divided into three groups of 13 patients each. A group (A) treated by conventional rehabilitation with manual traction, a group (B) treated with conventional rehabilitation with intermittent mechanical traction and a third group (C) treated with conventional rehabilitation alone. We evaluated cervical pain, radicular pain, disability and the use of analgesics at baseline, at the end and at 1, 3 and 6 months after treatment.

RESULTS

At the end of treatment improving of cervical pain, radicular pain and disability is significantly better in groups A and B compared to group C. The decrease in consumption of analgesics is comparable in the three groups. At 6 months improving of cervical and radicular pain and disability is still significant compared to baseline in both groups A and B. The gain in consumption of analgesics is significant in the three groups: A, B and C.

CONCLUSION

Manual or mechanical cervical traction appears to be a major contribution in the rehabilitation of CR particularly if it is included in a multimodal approach of rehabilitation.

Comparison of the intervertebral disc spaces between axial and anterior lean cervical traction

The insufficient investigations on the changes of spinal structures during traction prevent further exploring the possible therapeutic mechanism of cervical traction. A blind randomized crossover-design study was conducted to quantitatively compare the intervertebral disc spaces between axial and anterior lean cervical traction in sitting position. A total of 96 radiographic images from the baseline measurements, axial and anterior lean tractions in 32 asymptomatic subjects were digitized for further analysis. The intra- and inter-examiner reliabilities for measuring the intervertebral disc spaces were in good ranges (ICCs = 0.928-0.942). With the application of anterior lean traction, the statistical increases were detected both in anterior and in posterior disc spaces compared to the baseline (0.29 mm and 0.24 mm; both P < 0.01) and axial traction (0.16 mm and 0.35 mm; both P < 0.01). The greater intervertebral disc spaces obtained during anterior lean traction might be associated with the more even distribution of traction forces over the anterior and posterior neck structures. The neck extension moment through mandible that generally occurred in the axial traction could be counteracted by the downward force of head weight during anterior lean traction. This study quantitatively demonstrated that anterior lean traction in sitting position provided more intervertebral disc space enlargements in both anterior and posterior aspects than axial traction did. These findings may serve as a therapeutic reference when cervical traction is suggested.