From: Acta Radiol. 2009 Nov 16. [Epub ahead of print]

The pathogenesis and imaging findings in whiplash associated injury are poorly understood and remain debatable. The authors assessed the ligaments and membranes in the craniocervical junction with magnetic resonance imaging (MRI) in patients with whiplash associated injury and to compare them with healthy control subjects. Twenty-eight patients with whiplash associated injury were selected at random from a total number of 180 examined with MRI using 2-mm proton density (PD)-weighted images in three orthogonal planes at 1.5T. The patients were compared with 27 healthy control subjects without neck trauma.

High signal intensity of the alar and transverse ligaments was quite common and was reported at an average of about 50% both among patients and control subjects. The incidence of abnormalities of the tectorial and posterior atlantooccipital membranes was low in both groups. No statistically significant difference between control subjects and patients with whiplash associated injury was revealed for any of the structures assessed. Additional fat suppressed images seemed to reduce the number of reported anomalies. Due to lack of significant differences between patients with whiplash associated injury and healthy control subjects, it is not recommended that MRI with the current technique and classification system be used in the routine workup of patients with whiplash associated injury.

From: Yonsei Med J. 2009 Oct 31;50(5):624-9

Facet tropism is defined as asymmetry in both the facet joint angles of the lumbar and lumbosacral regions. For many years, the effect of facet tropism on the development of intervertebral disc degeneration has been debated. However, the specific details regarding the effects of facet tropism on the development of degenerative disc disease remains as the subject of debate. Most of the previous facet tropism studies have focused on the relationship between facet tropism and lumbar disc herniation.

The role of facet tropism in the pathogenesis of lumbar degenerative disc disease is not fully understood Currently, controversy exists surrounding the question of whether or not any significant relationship exists between facet tropism and the development of disc or facet joint degeneration. Additionally, the relationship between facet tropism and degenerative spondylolisthesis and translational segmental motion is highly controversial.

In the current study, the authors attempted to evaluate the effect of facet tropism on disc and facet joint degeneration. Additionally, the relationship between facet tropism and changes in translational segmental motion was investigated.

Facet tropism is defined as asymmetry between the left and right facet joint angles of the lumbar spine. Asymmetry in the orientation of the zygapophyseal joint surfaces is not uncommon, with estimates of its occurrence at 10-70.5% of the population. Our study revealed an incidence of facet tropism in 35% of the spinal units which were taken into consideration. Facet tropism is most common at L5-S1, followed by L4-L5.

The criteria for determining facet tropism have varied greatly, although the actual definition of facet tropism is asymmetry between the right and left facet joints. In the lumbar spine, the majority of facet joints vary by less than 7° in orientation between the two sides. Noren et al. defined facet asymmetry as a bilateral angle difference greater than 5°. In other biomechanical studies, facet asymmetry was defined as a difference in facet angles greater than 1-10° or one SD. Grogan, et al. divided facet joint tropism into three distinct classifications. When the orientation differed from one side to another by more than 7°, the facet joints at that level were defined as having tropism. Moderate tropism was defined as a difference of 7° to 15° between the orientation of the joints (one SD from the mean difference) and severe tropism was defined as a difference of more than 15° (two SDs from the mean) between the two sides. For the current study, the authors defined facet tropism to be bilateral angular asymmetry greater than 7°.

The angular difference inherent to facet joint tropism causes biomechanical issues. By definition, facet joint degeneration exists when one joint has more coronal orientation than the other. Farfan and Sullivan emphasized the importance of coronally facing facet joints upon the development of lumbar disc herniations. Coronally facing facet joints offer little resistance to shear intervertebral force, so that the joints tend to rotate toward the side of the more coronary facing facet joint, possibly leading to additional rotational stress on the annulus fibrosus. Loback, et al. showed that facet joint asymmetry is found more likely on the side of the coronally facing facet joint. When tropism was present, the motion segment was found to have a tendency to rotate towards the more oblique joint when axial loads were applied. This asymmetric axial rotation caused by tropism can place additional torsional loads on the intervertebral discs which can lead to intervertebral disc injury and degeneration. This biomechanical mechanism was used to describe the development of lumbar disc herniation, disc degeneration, and degenerative spondylolisthesis associated with facet tropism. Some studies have claimed that lumbar facet joint tropism does not accelerate degeneration of the facet joints. For the current study, the authors chose to investigate facet tropism and some of the findings associated with lumbar degenerative disc disease, including disc degeneration, facet joint degeneration, and spondylolisthesis (translational segmental motion).

The role of facet tropism in the pathogenesis of disc degeneration is a contested issue. Boden, et al. and Vanharanta, et al. reported no significant correlation between facet tropism and disc degeneration. However, Noren, et al. concluded that the existence of facet tropism can increase the risk of disc degeneration. Additionally, Dai reported that a significant correlation existed between facet joint tropism and the degree of disc degeneration in patients with degenerative spondylolisthesis. In the present study, no significant correlation was observed between facet joint tropism and disc degeneration at L3-L4, L4-L5, or L5-S1. However, a higher (but not statistically significant) incidence of highly degenerated discs at L4-L5 was observed within the facet tropism group.

Grogan, et al. concluded that lumbar facet joint tropism does not accelerate facet joint degeneration. They reported no significant differences in facet joint degeneration between facet joints with and without tropism. However, there are many limitations associated with this study. It was based on a small number of specimens (21 cadavers) and an even smaller number of lumbar facet joints exhibiting facet tropism (10 out of 104 lumbar facet joints). Additionally, this study did not take the level, where the tropism occurred, into consideration. Our current study included L3-L4, L4-L5, and L5-S1 facet joints belonging to 300 living participants and our findings were found to be similar to Grogan et al.’s at L3-L4 and L5-S1. However, at L4-L5, a significant correlation between facet joint tropism and facet joint degeneration was observed. Based on the fact that L4-L5 experiences the most segmental flexion and extension within the lower lumbar spine, this result suggests that the existence of facet tropism within highly mobile lumbar segments could affect the development of facet joint degeneration.

Berlemann, et al. reported that facet joint asymmetry does not seem to play a major role in the development of degenerative spondylolisthesis. However, Dai found that facet joint tropism was a predisposing factor for the development of degenerative spondylolisthesis. The present study found no association between facet tropism and translational segmental motion (such as vertebral slippage) within the lumbar spine. Our results indicate that facet tropism has no major association with the development of degenerative spondylolisthesis.

Previous reports have shown that facet orientation has a significant association with degenerative spondylolisthesis. Additionally, some of these studies reported that, in patients with degenerative spondylolisthesis, the transverse plane of facet joints was more sagittally oriented. All of these studies found that individuals with larger facetjoint angles, relative to the coronal plane (more sagittal orientation of facet joint), exhibited a higher incidence of degenerative spondylolisthesis. Although facet orientation was not taken into consideration for this study, the authors believe that it is an important element for understanding all of the factors that lead to the development of spondylolisthesis, and that this topic should be investigated further.

Another interesting factor to take into consideration is the existence of facet joint tropism within normal spines. This raises questions as to the root causality of facet joint tropism. Facet joint tropism could be caused by an inborn characteristic of the human spine, as a result of mechanical stresses on the spine (i.e., asymmetric loading of the human spine) or as a consequence of existing spinal deformities (i.e., scoliosis). Noren, et al. documented that subjects with lumbar degenerative disc disease had a higher incidence of facet joint tropism than the normal population. The nature of the relationship between facet joint tropism and degenerative changes within the lumbar spine remains a controversial topic. Essentially, there are two sides to this debate, one advocating that facet tropism leads to degeneration and the other claiming that certain degenerative statuses (i.e., degenerative spondylolisthesis) lead to facet tropism. Our results show that, at active functional spine units, facet tropism partially influences the development of facet joint degeneration. This seems to give legitimacy to the theory that facet tropism can lead to facet joint degeneration, although further investigation into the relationship between facet tropism and facet joint degeneration is necessary.

From: Indian J Med Sci. 2009 Oct;63(10):445-54

Neck pain is one of the most common problems in the population, which affects approximately 67% of individuals at some point of time in their lifetime. Regarding the 12-month prevalence of neck pain, previous research studies have reported it to range between 30% and 50%. Although it is not life threatening, it can cause a sense of being unwell and substantial level of disability due to pain and neck stiffness. This disability can affect the physical functioning of the patients, leading to sickness behavior and activity restrictions. In the general population, the 12-month prevalence of activity-limiting pain has been reported to vary from 1.7% to 11.5%.

The severity of neck pain and the related disability can affect daily social and functional activities, which may even involve emotional and psychological aspects. Thanks to the approval of the International Classification of Functioning, Disability and Health (ICF) by the World Health Assembly in 2001, neck pain and related consequences could be clearly understood and evaluated by a universal conceptual model termed as biopsychosocial health, which integrated the biomedical and societal models of functioning and disability. Hence, the outcome measures for any disease that predict the disease progress and response should carefully consider the biopsychosocial model involved in the evaluation of the disease process.

A few disease-specific outcome measurement tools that are available for assessing neck pain include neck disability index, neck pain and disability scale, Copenhagen neck functional disability scale, Northwick Park pain questionnaire, patient-specific functional scale self-reports with neck dysfunctions and the North American Spine Society cervical spine outcome assessment instrument. Interestingly, all the above-mentioned tools were developed considering the psychosocial aspects of western culture and were validated in the western context. These tools may have cultural bias and may be unsuitable for use in the Asian context because of the differences in the local cultural practices. Hence there was a need to develop a disease-specific outcome measurement tool for neck pain that reflects the local cultural practice. Thus, the neck pain and functional limitation scale was designed as a new outcome measurement tool to evaluate neck pain.

It is important that the newly developed outcome measurement tool must demonstrate reliability (consistency), validity (trueness) and responsiveness (the ability to detect change). If the results of the tool are valid, then it should measure the trait for which it was designed (content), be correlated to other measures of that trait (criterion) and must differentiate between the group with disease and the one without it. Hence the main aim of the present study was to create a new outcome measurement tool, neck pain and functional limitation scale, in order to assess the disability involved in neck pain and to report its reliability, concurrent validity and criterion validity.

Research on neck pain had shifted its focus away from the signs and symptoms. Rather, importance was laid on the specific effects of the symptoms on the patient’s functioning and daily life. The above facts were supported by a previous study which looked at neck function, physical function more holistically and at psychological function, which supported the reasons for inclusion of the multidimensional domains in the construction of neck pain and functional limitation scale. Therefore, the main 5 domains of neck pain and functional limitation scale are pain intensity, activities of daily living, functional domain, social domain and psychological domain. Each domain has four sub-items, which makes for a total of 20 items in the neck pain and functional limitation scale. The 5 main domains of the neck pain and functional limitation scale and the sub-items were framed from items generated from neck pain-focused group interviews, items generated from literature review and items generated from the information received from clinical specialists dealing with neck pain.

An initial neck pain and functional limitation scale questionnaire (consisting of 36 items) comprising of summarized items was prepared and was sent for a review. This review team consisted of 4 other senior physiotherapists specialized in musculoskeletal practice and a senior medical practitioner. The team came out with the final version of neck pain and functional limitation scale (20 items) after removing the unpopular items and adjusting the tool for domain and syntax. The main domains and each sub-item under every main domain in neck pain and functional limitation scale were presented as follows:

Domain 1 – Pain intensity: It consisted of 4 questions, which included neck pain rating, duration of neck pain, ability to manage neck pain and ability to tolerate neck pain.

Domain 2 – Activities of daily living (ADL): It consisted of 4 questions, which included dressing, head turning, television-viewing and carrying things.

Domain 3 – Social activities: It consisted of 4 questions, which were related to shopping, family relationships and interactions, traveling and recreational activities.

Domain 4 – Functional activities: It consisted of 4 questions, which included reading, using phone, looking up to search things above head level and work.

Domain 5 – Psychological factors: It consisted of 4 questions, which were related to sleeping, ability to concentrate, feeling of anxiousness and feeling of depression.

Previous studies that dealt with neck pain had identified rating of pain, duration of neck pain, ability to manage neck pain and the ability to tolerate neck pain as the important factors which were to be considered while assessing pain among patients with neck pain. Hence the pain intensity domain was supported with sub-items which included neck pain rating, duration of neck pain, ability to manage neck pain and ability to tolerate neck pain.

The physical factors associated with neck pain included heavy lifting, monotonous work tasks, static work posture, vibrations, repetitive jobs and a high work pace. However, the patients from the focused interview group identified activities such as turning head during driving, viewing television, carrying things and dressing as the main problems that resulted from their neck pain. These were included as items under the domain of activities of daily living.

Previous studies had pointed out that neck pain can affect social factors, which include shopping, family relationships and interactions, traveling and recreational activities. Hence these items were included to assess the effects of neck pain and disability within the social context. In the patient-specific focused group interview for neck pain, majority of the patients complained of neck pain while reading a newspaper or a book in a flexed neck position. Furthermore, previous studies had listed using phone, looking up to search things above head level and daily work as the main functional activities affected due to neck pain. Hence the functional activities domain consisted of 4 questions, which included reading, using phone, looking up to search for things above head level and normal daily work activities.

Previous research had shown a direct correlation between the pain level and the attention paid to psychosocial distress, especially anxiety and depression. Other psychological factors affected by neck pain were disturbed sleep due to pain, lack of ability to concentrate and focus, feelings of anxiety and depression. Disturbed sleep and sense of depression were commonly cited by the individuals in the neck pain focus group as disabling factors related with neck pain. Therefore, the psychological domain consisted of 4 questions, which included those related to sleeping, ability to concentrate and focus, and feelings of anxiousness and depression.

This study has some strength in that the subjects with neck pain recruited in the study represented a variety of cervical problems, ranging from cervical spondylosis to cervical disc prolapse. The recruitment of patients with both nonspecific neck pain and specific neck pain (a structural damage to the neck tissue) allowed the applicability of neck pain and functional limitation scale to various types of neck pathologies. Similarly, the age range of the patients who participated in this study also consisted of both younger and older age groups of patients. Hence it could be said that neck pain and functional limitation scale may be applied to different age groups. Strength may be accounted for by the process of designing the neck pain and functional limitation scale. Previous tools related with neck pain configured questionnaire items based on literature reviews and were compared with a patient-specific tool. The neck pain and functional limitation scale was designed by collecting information using patient-specific methods, expert opinions, along with the items supported scientifically through literature search.

The present study supported the validity of neck pain and functional limitation scale because the performance of the neck pain and functional limitation scale was comparable to the established standards of the neck bournemouth questionnaire. The study results suggested that the neck pain and functional limitation scale was a highly reliable outcome measurement tool to evaluate neck pain and underlying disability.

Tags: neck, pain,, neck, pain, and, functional, limitation, scale,, outcome, measurement

From: Man Ther. 2009 Nov 4

The mechanisms underlying sensory hypersensitivity in acute whiplash associated disorders are not well understood. We examined the extent of the relationships between the sensory measures of pressure pain threshold and cold pain threshold, catastrophizing, pain and disability levels and gender in acute whiplash associated disorders. Thirty-seven subjects reporting neck pain following a motor vehicle accident were examined within five weeks post-injury. Measures of neck pain and disability (Neck Disability Index and catastrophizing (Pain Catastrophizing Scale) were taken. Cold pain threshold was assessed in the cervical spine and pressure pain thresholds were assessed in the cervical spine (pressure pain threshold cx) and at a remote site (pressure pain threshold distal). Cold pain threshold and Pain Catastrophizing Scale were moderately correlated; however there were no significant relationships between pressure pain threshold (cervical and distal) and Pain Catastrophizing Scale. Both cold pain threshold and pressure pain threshold cx were significantly correlated with Neck Disability Index but pressure pain threshold distal was not. Finally, gender modulated the relationships between sensory measures, catastrophizing, and pain and disability levels. In conclusion, subjects with higher levels of catastrophizing presented with sensory hypersensitivity to cold stimuli in the acute phase of whiplash. Differences between genders are in accordance with the growing body of evidence suggesting that the relationships between some psychological factors and injury related symptoms are modulated by gender.

Tags: pain, thresholds,, catastrophizing,, gender,, whiplash

From: J Rehabil Res Dev. 2009;46(4):499-514

For conventional motor vehicle seats, a head restrainteffectively reduces whiplash injuries to the neck in rear impact collisions, because it substantially reduces relative motion between the occupant’s head and chest. For wheelchair occupants traveling in adapted vehicles, a risk of whiplash injuries also exists, either for forward facing wheelchairs in a rear impact collision or for rearward facing wheelchairs in a frontal collision. However, unlike for motor vehicle seats, the provision of wheelchair head restraints is unregulated and testing of wheelchair head restraints in the mid-1990s indicated that commercial products failed in static tests through plastic bending of the vertical adjuster or pullout forces on the attachment bracket. Recent sled testing of head restraints for child wheelchair users showed that their presence significantly reduced a head restraint head fracture, concussion, and serious neck injury risk for rear impacts. However, how these findingsapply to AIS1 neck injury risk for adults in lower velocity rear impact whiplash cases is unclear. To address this problem, the authors performed a series of nine adult wheelchair occupant rear impact sled tests, where the BioRID-II was seated in a surrogate wheelchair. Tests were performed with and without a head restraint, and a new prototype and anexisting commercial head restraint were used.

Many wheelchair users remain in their wheelchairs during transit. Safety research for wheelchair users has focused mainly on frontal impact. However, although they are generally less severe, rear impact injuries are expensive and difficult to treat and whiplash injury protection for adult wheelchair users remains poorly understood. In this article, rear impact sled tests conducted with the Biofidelic Rear Impact Dummy II or BioRID-II seated in a rigid wheelchair with no head restraint showed that Abbreviated Injury Scale-score 1 neck injury risk evaluated with the neck injury criterion (NIC) and Nkm criterion is substantially above proposed threshold levels. A prototype wheelchair head restraint was developed and tested together with an existing commercial head restraint in the same rear impact. Both head restraints reduced the injury scores substantially. NIC test scores for the head restraints with no gap ranged from 18 to 24 (approximately 20%-30% chance of neck injury symptoms of duration >1 month) compared with test scores for no head restraints that ranged from 34 to 37 (approximately 95% chance of neck injury). The corresponding extension-posterior Nkm scores with no gap ranged from 0.30 to 0.35 (approximately 5% chance of neck injury) compared with no head restraint of 1.16 (approximately 45% chance of neck injury symptoms). However, the number of sled tests performed was small (three with no head restraint and six with a head restraint), and these results should be considered mainly trends. Preliminary results also showed that the horizontal gap between the head and the wheelchair head restraint cushion should be as small possible.

Tags: wheelchair,, whiplash,, neck, injury

From: Ann Fam Med. 2009 Sep-Oct;7(5):446-54

Complaints of arm, neck, and shoulder pain are very common in Western societies. In the Netherlands the estimated 12-month prevalence in the general population was 31% for neck pain, 30% for shoulder pain, 11% for elbow pain, and 18% for wrist or hand pain. Studies have reported that of the respondents with noninflammatory musculoskeletal pain, about 30% to 45% contacted their general practitioner. In Dutch general practice, incidence data for patients with nontraumatic arm, neck, or shoulder complaints show 97 consultations per 1,000 registered persons annually.

Common management options for patients with nontraumatic arm, neck, and shoulder complaints are watchful waiting, additional diagnostic tests, prescription of medication, referral for physiotherapy, a corticosteroid injection, and referral for medical specialist care. Use of these 6 management options shows wide variation, however, both between and within diagnostic groups. Until now, no studies have evaluated the determinants that contribute to variation in the management of these complaints. Part of this variation may be explained by the diagnosis, which, because of its natural course and available treatment, usually guides management. Also, patient and complaint characteristics may influence management. In the Netherlands guidelines issued by the Dutch College of General Practitioners are available for epicondylitis and shoulder complaints; in both guidelines, management advice is partly based on differences in the levels of hindrance (pain severity and functional limitations). In other study populations, patient and complaint characteristics reported to be associated with management options are distress, poor perceived health, age, and sex. Additionally, indicators of poor prognosis can play a role in management decisions. In our earlier study in this population, indicators of poor prognosis were long duration of the complaints at baseline, having musculoskeletal comorbidity, recurrent complaint, low social support, and a high somatization level.

The authors wanted to evaluate associations between diagnosis and characteristics of the patient, complaint, and general practitioner, as well as 6 common management decisions, in patients with nontraumatic arm, neck, and shoulder complaints at the time of the first consultation with their physician. They undertook an observational cohort study set in 21 Dutch general practices, including 682 patients with nontraumatic complaints of arm, neck, and shoulder. The outcome measure was application (yes/no) of a specific management option: watchful waiting, additional diagnostic tests, prescription of medication, corticosteroid injection, referral for physiotherapy, and referral for medical specialist care. Separate multilevel analyses showed that overall, the diagnostic category, having long duration of complaints, and reporting many functional limitations were most frequently associated with the choice of a management option. For watchful waiting, only complaint variables played a role (long duration of complaints, high complaint severity, many functional limitations, recurrent complaint). All these variables were negatively associated with watchful waiting. When opting for 1 of the 5 other management options, several physician characteristics played a role as well. Less clinical experience was associated with additional diagnostic tests and referral to a medical specialist. General practitioners working in a solo practice more frequently referred to a medical specialist. General practitioners working in a rural area more frequently referred for physiotherapy. Female General practitioners prescribed medication less frequently. Physicians with special interest in musculoskeletal complaints gave corticosteroid injections more frequently.

Diagnostic category, long duration of complaints, and high functional limitations were key variables in management decisions with arm, neck, and shoulder complaints complaints. In addition, several physician characteristics played a role as well.

Tags: arm, pain,, neck, pain,, shoulder, pain

From: Man Ther. 2009 Oct;14(5):475-9

The cranio-cervical flexion test tests the coordination of the deep and superficial cervical flexor muscles during a cranio-cervical flexion task. The test has revealed impairments in muscle function in younger/middle aged patients with various neck pain disorders. Neck pain and headache are common in elders but it is unknown if age alone affects performance in the cranio-cervical flexion test. This study compared performance in the cranio-cervical flexion test between healthy asymptomatic elderly and younger subjects. Electromyographic (EMG) amplitude in the sternocleidomastoid, angle of cranio-cervical flexion and ability to target the pressure levels of each test stage were examined in 44 elderly and 39 young participants.

The results indicated that the elderly group had higher measures of normalized EMG signal amplitude in the sternocleidomastoid during the test, greater shortfalls from the target pressures of all stages of the test, except for the 22 mm Hg stage, and larger variability of the cranio-cervical flexion range of motion for the five successive stages of the test (particularly at 26, 28 and 30 mm Hg stages) compared to young subjects. Clinicians must be aware of this occurrence when assessing performance in the cranio-cervical flexion test in elders with neck pain.

Tags: Cranio-cervical, flexion, test,, elderl,, neck, pain

From: Ann Phys Rehabil Med. 2009 Oct 8.

The objective of this study was to assess the effect of mechanical and manual intermittent cervical traction on pain, use of analgesics and disability during the recent cervical radiculopathy. The authors 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. The authors 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.

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

Tags: cervical, traction,, radiculopathy,, rehabilitation

From: Spine (Phila Pa 1976). 2009 Oct 16

The effect of postural change on degenerative lumbar discs was quantified using novel kinematic magnetic resonance imaging. The purpose is to describe the bulging of degenerative intervertebral lumbar discs in vivo subjected to different postural loads using a novel kinematic magnetic resonance imaging.

Symptomatic lumbar disc degeneration is a leading cause of pain and disability throughout the world. Over 70% of US citizens will experience a debilitating episode of low back pain. Earlier reports of degenerative disc changes are cadaver studies or are performed with recumbent MRI that eliminates the functional effects of gravity and muscle power. Little data are available on the behavior of degenerative intervertebral discs in vivo under physiologic loads.

A total of 513 patients obtained kMRI. Disc bulging beyond the intervertebral space was quantified during upright neutral, flexion, and extension imaging. The degree of intervertebral disc degeneration was correlated using the Pfirrmann Classification. Moderately degenerated intervertebral discs (grade III and IV) demonstrated greater bulging than mildly degenerated discs (grade II). Severely degenerated discs (grade V) also showed a trend toward greater bulging, but this was not significant. Grade I discs at all levels moved posteriorly in flexion and anteriorly in extension when compared to neutral posture. However, mild to severe (grade II-V) degenerative discs behaved differently in response to postural loads. Extension resulted in significant posterior bulging, while flexion did not demonstrate obvious anterior derangement.

Disc bulging increases with the severity of disc degeneration. Grade I discs demonstrate the expected sagittal migration in response to postural load. However, more degenerative discs behave less predictably, and spine extension may result in significant posterior disc bulging. Degenerative changes in the intervertebral disc significantly affect the kinematic patterns under postural load in vivo. Kinematic magnetic resonance imaging is a useful tool to quantify the kinematic behavior of degenerative intervertertebral discs.

Tags: degenerative, lumbar, discs,, symptomatic, lumbar, disc, degeneration,, postural, load

From: Spine (Phila Pa 1976). 2009 Oct 15;34(22):2389-94

This article investigates the effects of cervical disc herniation on kinematics at adjacent vertebral motion segments. Kinetic magnetic resonance imaging is an alternative method to conventional MRI, which allows evaluation of the cervical spine in a more physiologic, weight-bearing position, and acquisition of images in flexion, extension, and neutral alignment. Kinetic magnetic resonance imaging has previously been used to evaluate the effects of disc degeneration on cervical kinematics. A total of 407 patients with neck pain without prior history of surgery were evaluated using kinetic magnetic resonance imaging. Translational motion, angular variation, and disc height were measured at each segment from C2-C3 through C7-T1. Other factors including the degree of disc degeneration, age, gender, and vertebral segment location were analyzed in order to determine any predisposing risk factors for segmental instability adjacent to disc herniations.

Spinal levels above the disc herniation exhibited, on average, a 7.2% decrease in translational motion per mm of disc herniation, without significant change in angular motion. Levels below the herniation demonstrated a 5.2% decrease in angular motion per mm of disc herniation without significant change in translational motion. The degree of disc degeneration had no significant effect on adjacent level motion. Disc herniation had no significant impact on disc height at adjacent levels, although disc degeneration correlated with decreased disc height above and increased disc height below.

Although disc height, translational motion, and angular variation are significantly affected at the level of a disc herniation, no significant changes are apparent in adjacent segments. This study indicates that herniated discs have no effect on ROM at adjacent levels regardless of the degree of disc degeneration or the size of disc herniation, suggesting that the natural progression of disc degeneration and adjacent segment disease may be separate, unrelated processes within the cervical spine.

Tags: cervical, disc, herniation,, cervical, kinematics,, disc, degeneration