Immunohistochemical and histological study of human uncovertebral joints
From: Spine (Phila Pa 1976). 2009 May 20;34(12):1257-63
There is controversy with regard to the anatomic and histological makeup of the uncovertebral interface with some authors considering it a joint and others disc tissue. No research has investigated the presence of pain generating neurotransmitters within the uncovertebral cartilaginous and capsular tissue.
The objective of this study was to investigate the anatomy and innervation of the uncovertebral joint to determine if it is synovial in nature and capable of generating pain.
Tissue from uncovertebral capsule and cartilage was harvested for each uncovertebral surface starting at the C2-C3 to the C6-C7 cervical segment. The tissue was placed in 4% paraformaldehyde fixative, then dehydrated and embedded in paraffin. Ten micron sections were cut through the tissue blocks and mounted on slides. The tissue was rehydrated and either stained with hematoxylin and eosin (H and E) or immunostained with antisera against protein gene product 9.5 (PGP 9.5), substance P (SP), neuropeptide Y (NPY), and calcitonin gene-related peptide (CGRP).
The sample consisted of 2 unembalmed fresh male human cadavers of a mean age of 83 years. Chondrocytes and synoviocytes were identified at the capsular tissue of each uncovertebral interface from C2-C3-C6-C7. Immunoreactivity for PGP 9.5, SP, CGRP, and NPY was observed at all uncovertebral interface levels in capsular tissue.
The presence of both synoviocytes and chondrocytes has been recorded in the present study, suggesting that the uncovertebral interface is synovial in nature. Immunoreactivity to PGP 9.5, SP, CGRP, and NPY indicates the presence of nerve fibers from both the somatic and autonomic nervous systems. These findings suggest that the uncovertebral joints are potential pain generators in the cervical spine.
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Prevalence and correlates of musculoskeletal pain in Chinese elderly and the impact on 4-year physical function and quality of life
From: Public Health. 2009 Aug 24
Examination of the prevalence, correlates and prospective impact of musculoskeletal pain on physical and psychological function in a population health survey of elderly Chinese men and women. Four thousand men and women, aged 65 years and over, living in the community in Hong Kong took part in this study. A questionnaire to determine demographics, socio-economic status, medical history, smoking, alcohol intake and level of physical activity was administered by an interviewer. Participants were asked about the presence of pain in the back, neck, hip and knee in the past 12 months. They were re-interviewed after 4 years of follow-up to document physical performance measures, psychological function and occurrence of falls, fractures and mortality.
Overall, back pain was most prevalent (48%), followed by knee (31%), neck (22.5%) and hip (8.9%) pain; the values was nearly twice as high in women compared with men for all sites. The presence of pain was not correlated with age, but was associated with various measures of socio-economic status as well as comorbidities. Baseline prevalence of pain was related to physical performance and quality-of-life measures, and fracture incidence after 4 years of follow-up.
Musculoskeletal pain is prevalent among elderly men and women, being much higher in the latter, giving rise to considerable functional and psychological impairments. Osteoporosis and osteoarthritis are likely to be the main underlying causes. The condition may be considered part of the frailty syndrome, and in this context, prevention and management represent major public health challenges.
Increased expression of matrix metalloproteinase-10, nerve growth factor and substance P in the painful degenerate intervertebral disc
From: Arthritis Res Ther. 2009 Aug 20;11(4):R126. [Epub ahead of print]
The human intervertebral disc is an avascular and aneural tissue comprising a central gelatinous region (the nucleus pulposus), surrounded by a fibrous ring of highly organised collagen fibres (the annulus fibrosus). The extracellular matrix of the nucleus pulposus is rich in type II collagen and proteoglycans, predominantly aggrecan, which produces a highly hydrated matrix capable of withstanding the loads experienced within the spine. This extracellular matrix is constantly being remodelled in a process driven by the constituent nucleus pulposus cells.
During intervertebral disc degeneration there is an imbalance in the normal homeostatic mechanisms, which favours matrix catabolism and leads to a loss of disc height,
coupled with ingrowth of both nerves and blood vessels into both the annulus fibrosus and nucleus pulposus. The authors have previously demonstrated that this ingrowth of nerves into the degenerate intervertebral disc is associated with low back pain. While low back pain is multifactorial, studies have shown that this debilitating condition affecting around 80% of adults at some stage of life is associated with intervertebral disc degeneration in approximately 40% of cases. Indeed in a recent study by Cheung et al (2009) it has been shown that there is a significant association of lumber disc degeneration imaged by MRI with low back pain.
The nucleus pulposus of the normal human intervertebral disc is an avascular and aneural environment, comprising of chondrocyte like cells embedded within an extracellular matrix rich in proteoglycans and collagens. This matrix is continuously remodelled in a process controlled by the nucleus pulposus cells and closely regulated by anabolic growth factors and catabolic cytokines. In intervertebral disc degeneration there is disregulation in this finely balanced homeostatic matrix turnover mechanism, leading to an increase in catabolic processes over anabolic matrix formation. Over time this results in breakdown of matrix, until the disc loses both height and function and in a large proportion of cases there is innervation and initiation of the pain response which leads to low back pain.
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The clinical presentation of chronic whiplash and the relationship to findings of MRI fatty infiltrates in the cervical extensor musculature: a preliminary investigation
From: Eur Spine J. 2009 Aug 12. [Epub ahead of print]
The objective was to determine whether any measurable changes in sensory responses, kinesthetic sense, cervical motion, and psychological features were related to established fatty infiltration values in the cervical extensor musculature in subjects with persistent whiplash. It is unknown if fatty infiltrate is related to any signs or symptoms. Data on motor function, Quantitative Sensory Testing, psychological and general well-being, and pain and disability were collected from 79 female subjects with chronic whiplash. Total fat values were created for all subjects by averaging the muscle fat indices by muscle, level, and side from our MRI dataset of all the cervical extensor muscles.
Results of this study indicate the presence of altered physical, kinesthetic, sensory, and psychological features in this cohort of patients with chronic whiplash. Combined factors of sensory, physical, kinesthetic, and psychological features all contributed to a small extent in explaining the varying levels of fatty infiltrate, with cold pain thresholds having the most influence. Identifying and relating quantifiable muscular alterations to clinical measures in the chronic state, underpin some clinical hypotheses for possible pathophysiological processes in this group with a chronic and recalcitrant whiplash disorder. Future research investigations aimed at accurate identification, sub-classification, prediction, and management of patients with acute and chronic whiplash is warranted and underway.
The effect of two exercise regimes; motor control versus endurance and strength training for patients with whiplash associated disorders
From: Clin Rehabil. 2009 Aug 5. [Epub ahead of print]
The objective of this pilot study was to compare the effect of exercise regimes with focus on either motor control training or endurance and strength training for patients with whiplash associated disorders in the subacute phase. An outpatient spine clinic in Norway recruited twenty five subjects with a whiplash associated disorder still having symptoms or disability six weeks after injury.
The whiplash associated disorder participants received 6 to 10 sessions of physiotherapy for six weeks with focus on either motor control or endurance and strength of neck muscles. The primary outcome measure was the Neck Disability Index, while the secondary outcome measures were pain intensity, neck functioning and sick leave.
No statistical significant differences concerning primary and secondary outcome measures were demonstrated between the groups. Approximately half of the participants in both groups obtained clinically important improvement on perceived disability assessed by Neck Disability Index at six weeks and one year follow up. The changes within both groups were statistically significant at six weeks, but not at one year follow up. For most pain related variables clinical significant improvement was demonstrated in both groups at six weeks, but for fewer participants at one year. There was also statistical significant improvement within groups in some of the physical performance tests at one year follow up.
The changes associated with motor control training and endurance and strength training of neck muscles were similar for reduced disability, pain and for improving physical performance. With a low number of participants and no control group, however, the authors could not be sure whether the improvements are due to interventions or other reasons.
Responsiveness of the Neck Disability Index in patients with mechanical neck disorders
From: Spine J. 2009 Jul 24. [Epub ahead of print]
The purpose of this study was to report the test-retest reliability, construct validity, minimum clinically important difference, and minimal detectable change for the Neck Disability Index.
Cohort study of patients presenting to outpatient physical therapy clinics. Ninety-one subjects with a primary complaint of neck pain, with or without concomitant upper extremity symptoms, who were participants in a randomized clinical trial. Neck Disability Index and the 15-point Global Rating of Change self-report measures. All subjects completed the Neck Disability Index at baseline and at a 3-week follow-up. Additionally, subjects completed the Global Rating of Change scale, which was used to dichotomize patients into improved or stable groups. Changes in the Neck Disability Index were used to assess test-retest reliability, construct validity, minimum clinically important difference, and minimal detectable change.
Test-retest reliability was moderate for the Neck Disability Index (intraclass correlation coefficient, 0.64; 95% confidence interval, 0.19-0.84). For the Neck Disability Index, the minimum clinically important difference was 7.5 points and the minimal detectable change was 10.2 points. The Neck Disability Index appears to demonstrate adequate responsiveness based on statistical reference criteria when used in a sample that approximates the high percentage of patients with neck pain and concomitant upper extremity referred symptoms. Because the minimum clinically important difference is within the bounds of measurement error, a 10-point change (the minimal detectable change) should be used as the minimum clinically important difference.
