Low back pain scores correlate with the cytokine mRNA level in lumbar disc biopsies: a study of inflammatory markers in patients undergoing lumbar spinal fusion.

PURPOSE: The molecular mechanism behind pain in degenerative disc disease (DDD) and chronic low back pain (LBP) patients is largely unknown. This present study examines the association of LBP and disability to mediators of the inflammatory cascade, as indexed by mRNA gene expression of pro-inflammatory cytokine markers in the intervertebral disc (IVD). METHODS: Biopsies of the annulus fibrosus (AF) and the nucleus pulposes (NP) from patients with DDD undergoing 1-2 level fusion surgery at L4/L5 or L5/S1 were obtained from total of 34 patients [9 M, 25 F] with average age of 53 [32-63]. The mRNA expression of TNF-α, IL-1ß, and IL-6 in the AF and NP was analyzed using quantitative real-time polymerase chain reaction (RT-qPCR), and the expression level of these markers was correlated to the visual analogue scale (VAS) and Oswestry Disability Index (ODI) scores (0-100) for pain and disability. RESULTS: We report a statistically significant positive correlation between pain intensity (VAS score) and the expression of TNF-α in both the AF (r = 0.54, p = 0.001) and NP (r = 0.40, p = 0.02), similarly with IL-1ß in AF (r = 0.37, p = 0.02) and IL-6 in NP (r = 0.40, p = 0.02). In addition, we found significant positive correlation observed between disability score (ODI) and expression of IL-6 in both AF (r = 0.36, p = 0.03) and NP (r = 0.41, p = 0.01). CONCLUSION: We conclude that the intensity of LBP and disability is associated with the level of inflammation in the disc.

Clinical assessment of prognostic factors for long-term pain and handicap after whiplash injury: a 1-year prospective study.

BACKGROUND AND PURPOSE: Physical mechanisms are the possible factors involved in the development and maintenance of long-term handicaps after acute whiplash injury. This study prospectively examined the role of active neck mobility, cervical and extra-cervical pains, as well as non-painful complaints after a whiplash injury as predictors for subsequent handicap. METHODS: Consecutive acute whiplash patients (n = 688) were interviewed and examined by a study nurse after the median of 5 days after injury, and divided into a high- or a low-risk group by an algorithm based on pain intensity, number of non-painful complaints and active neck mobility [active cervical range of motion (CROM)]. All 458 high-risk patients and 230 low-risk patients received mailed questionnaires after 3, 6 and 12 months. Two examiners examined all high-risk patients (n = 458) and 41 consecutive low-risk patients at median 11, 109, 380 days after injury. The main outcome measures were: handicaps, severe headaches, neck pain and neck disability. RESULTS: The relative risk for a 1-year disability increased by 3.5 with initial intense neck pain and headaches, by 4.6 times with reduced CROM and by four times with multiple non-painful complaints. CONCLUSION: Reduced active neck mobility, immediate intense neck pain and headaches and the presence of multiple non-painful complaints are the important prognostic factors for a 1-year handicap after acute whiplash.

Modic changes, possible causes and relation to low back pain.

UNLABELLED: In patients with low back pain (LBP) it is only possible to diagnose a small proportion, (approximately 20%), on a patho-anatomical basis. Therefore, the identification of relevant LBP subgroups, preferably on a patho-anatomical basis, is strongly needed. Signal changes on MRI in the vertebral body marrow adjacent to the end plates also known as Modic changes (MC) are common in patients with LBP (18-58%) and is strongly associated with LBP. In asymptomatic persons the prevalence is 12-13%. MC are divided into three different types. Type 1 consists of fibro vascular tissue, type 2 is yellow fat, and type 3 is sclerotic bone. The temporal evolution of MC is uncertain, but the time span is years. Subchondral bone marrow signal changes associated with pain can be observed in different specific infectious, degenerative and immunological diseases such as osseous infections, osteoarthritis, ankylosing spondylitis and spondylarthritis. In the vertebrae, MC is seen in relation to vertebral fractures, spondylodiscitis, disc herniation, severe disc degeneration, injections with chymopapain, and acute Schmorl's impressions. The aim of this paper is to propose two possible pathogenetic mechanisms causing Modic changes. These are: A mechanical cause: Degeneration of the disc causes loss of soft nuclear material, reduced disc height and hydrostatic pressure, which increases the shear forces on the endplates and micro fractures may occur. The observed MC could represent oedema secondary to the fracture and subsequent inflammation, or a result of an inflammatory process from a toxic stimulus from the nucleus pulposus that seeps through the fractures. A bacterial cause: Following a tear in the outer fibres of the annulus e.g. disc herniation, new capilarisation and inflammation develop around the extruded nuclear material. Through this tissue it is possible for anaerobic bacteria to enter the anaerobic disc and in this environment cause a slowly developing low virulent infection. The MC could be the visible signs of the inflammation and oedema surrounding this infection, because the anaerobic bacteria cannot thrive in the highly aerobic environment of the MC type 1. PERSPECTIVES: One or both of the described mechanisms can - if proven - be of significant importance for this specific subgroup of patients with LBP. Hence, it would be possible to give a more precise and relevant diagnosis to 20-50% of patients with LBP and enable in the development of efficient treatments which might be antibiotics, special rehabilitation programmes, rest, stabilizing exercise, or surgical fixation, depending on the underlying cause for the MC.

Biomechanics of forward-reaching movements while sitting on fixed forward- or backward-inclining or tiltable seats.

Possible differences in spinal stress were evaluated during forward-reaching movements from chairs with, respectively, fixed backward-inclining, forward-inclining, and tiltable seat. Twenty-four healthy subjects, 12 female and 12 male, performed rhythmical sagittal movements with pins over a 40-cm distance. The posture in an upright and in a forward position was described by means of seven variables, measured by an inclinometer. Posture changes between these positions were then compared for the three types of chairs. No significant influence from the chairs on posture changes was observed. Thus, no variation in spinal stress can be anticipated during forward-reaching movements in any of the three types of chair. The discussion also presents a current status regarding tiltable and fixed forward-inclining seats.

Lumbar curve, trunk muscles, and line of gravity with different heel heights.

The influence of different heel heights on the lumbar curve, pelvic inclination, trunk muscle activity, and the position of the line of gravity was examined in 18 healthy women. They were examined while standing on heel-supports, being 4.5 cm elevated, at the level of and 2.5 cm lower than the support of the forefoot, respectively (Figure 1). Each examination was preceeded by one-hour adaptation to a corresponding shoe type. With increasing heel height, the lumbar lordosis and the pelvis inclination were decreased. The back and abdominal muscles did not alter their activities. The position of the line of gravity kept the distance from the forefoot almost constant, but the ankle joint was shifted towards the line of gravity with increasing heel height.

Trunk posture and trapezius muscle load while working in standing, supported-standing, and sitting positions.

A study of standing, supported-standing ("riding" on a rounded seat), and sitting postures was carried out on persons simulating assembly work in places with poor leg space. These postures and the upper trapezius muscle load were examined using statometric and electromyographic methods, respectively. While supported-standing or sitting, the lumbar spine moved toward kyphosis, even where there was no backward rotation of the pelvis. In adopting the position for anteriorly placed work, the upper arms were raised 30 degrees forward or more; then, if a greater reach was necessary, the trunk was flexed as well. It is concluded that if leg space is poor, variation between supported-standing and standing should be encouraged, and an ordinary office chair avoided. Working level should be arranged so that it is lower than 5 cm above elbow level if no arm/wrist support is possible.

Can it be predicted which patients with chronic low back pain should be offered tertiary rehabilitation in a functional restoration program? A search for demographic, socioeconomic, and physical predictors.

STUDY DESIGN: A prospective clinical trial was conducted that involved six groups of patients with chronic low back pain selected from a large cohort (N = 816). OBJECTIVES: To correlate pretreatment baseline variables with outcome parameters after treatment in a functional restoration program or in control programs, to identify possible factors predictive of the need for functional restoration. SUMMARY OF BACKGROUND DATA: Since the functional restoration program was first described, research has focused on identifying patients who will or will not benefit from such a program. The value of previous studies is limited, however, because predictive factors from a control group were not "subtracted." METHODS: Eight hundred sixteen patients with chronic low back disability were included. All had a structured medical examination, including various physical tests before participation in either a functional restoration program (n = 621) or shorter "control" outpatient programs (n = 144). A smaller group of the cohort (n = 51) had no treatment and served as a pure control group. Six groups were selected from the cohort: Three underwent an identical functional restoration program and three underwent different outpatient control programs. Several baseline demographic, physical, and socioeconomic variables were correlated to 1-year outcome parameters. RESULTS: Age, days of sick leave, connection to the work force, and back pain intensity, were significantly correlated to success 1 year after entry into the study in all groups, no matter what kind of treatment was administered. Back muscle endurance, sports activity, activity of daily living scores, and vibrations were of importance in some outcome parameters for success after functional restoration. Smoking was positively correlated to disability pension. Days of sick leave and, in functional restoration, ability to work were the only factors that were correlative with statistics for people who withdrew. CONCLUSIONS: Different factors can be identified as predictive of outcome in a functional restoration program, but most of these factors were also shown to predict success for shorter control outpatient programs or of no treatment.

Functional restoration versus outpatient physical training in chronic low back pain: a randomized comparative study.

STUDY DESIGN: A randomized parallel-group comparative trial with a 1-year follow-up period was performed. OBJECTIVE: To compare the effect of a comprehensive functional restoration program involving intensive physical training, ergonomic training, and behavioral support (39 hours per week for 3 weeks) with the effect of outpatient intensive physical training (1.5 hours three times per week for 8 weeks). SUMMARY OF BACKGROUND DATA: Nonrandomized studies conducted in the United States favor functional restoration for patients with chronic low back pain. Two previously reported randomized studies from the authors' Back Center in Copenhagen concur with this recommendation, although the positive effects in one of the studies had faded out after 2 years. Randomized functional restoration studies in Canada and Finland have failed to demonstrate any substantive effect. METHODS: Initially, 138 patients with chronic low back pain were included in the current study. They then were randomized to either functional restoration (n = 64) or outpatient intensive physical training (n = 74). Of the initial 138 patients, 11 never started (5 and 6, respectively); 21 dropped out during treatment (8 and 13); and 7 of the graduates did not take part in the 1-year follow-up evaluation (3 and 4). The conclusions were drawn from the 99 patients (48 and 51, respectively) who graduated and participated in a 1-year follow-up evaluation. The median age of the patients was 42 years (range, 21-55 years) The female-to-male ratio was 68 to 31, and the median sick leave days during the preceding 3 years was 180 (range, 0-1080 days). The average back pain was rated 5.5 on a scale of 0 (no pain) to 10 (maximal pain). For these variables, there were no important differences between the groups. However, the functional restoration group tended to be more capable of work at baseline (58% vs 42%; P = 0.09). RESULTS: At the 1-year follow-up evaluation, overall assessment favored functional restoration. Otherwise, no significant differences were observed regarding work capability, sick leave for those at work, health care contacts,back pain, leg pain, or self-reported activities of daily living. CONCLUSIONS: Only in terms of overall assessment, the functional restoration program was superior to a comparatively short time-consuming outpatient physical training program. DISCUSSION: It may be that lower economic benefits during sick leave in the United States lead to favorable results from functional restoration programs, whereas greater benefits in Canada, Finland, and Denmark result in different conclusions. Finally, it may be that the difference in results across studies points simply to whether the studies were randomized.

Functional restoration for chronic low back pain. Two-year follow-up of two randomized clinical trials.

STUDY DESIGN: Two randomized, prospective clinical trials involving 238 chronic low back disability patients were carried out. Results at 2-year follow-up are presented. OBJECTIVES: To compare the clinical outcomes of a multidisciplinary functional restoration program with a nontreated control group (Project A) and with two less intensive but different training programs (Project B). SUMMARY OF BACKGROUND DATA: The effectiveness of functional restoration programs has not been firmly established. Results from trials carried out in the United States differ from those in trials conducted in other countries. Only a few of these studies have been carried out as prospective and randomized clinical studies. METHODS: Two hundred thirty-eight patients with chronic low back disability of at least 6 months' duration were included. There were 106 patients in project A and 132 patients in project B. Two years after completion of treatment patients were mailed a questionnaire that included questions regarding their work status, pain and disability levels, number of sick leave days, number of medical care contacts, medication use, physical activity levels, and subjective overall assessment of their "back life situation." RESULTS: Patients in both studies were comparable at inclusion, except that patients in Project A were recruited from all of Denmark, whereas those in Project B were from the greater Copenhagen area. Thirteen patients did not report for treatment after randomization. Of the remaining 225 patients, 20 (9%) did not complete treatment. The questionnaire response rate was 94%. In Project A, those patients receiving treatment (functional restoration) reported significantly less contact with the health care system, fewer sick leave days, and a less disabled life style during the follow-up period, compared with reports of patients in the control group. Other effect parameters did not demonstrate a significant difference between the two groups. In Project B, all effect parameters reported, except leg pain and medication usage, were significantly in favor of functional restoration, compared with reports from the less intensively treated groups. CONCLUSIONS: The functional restoration program seems effective in various parameters compared with the less intensive programs, but the differences in outcome in the two parallel studies indicate the necessity of testing a treatment program in different settings, in that the statistical variation may be a major factor in results of different studies.

Intensive training, physiotherapy, or manipulation for patients with chronic neck pain. A prospective, single-blinded, randomized clinical trial.

STUDY DESIGN: A randomized, prospective clinical study was conducted that included 119 patients with chronic neck pain of greater than 3 months' duration. OBJECTIVES: To compare the relative effectiveness of intensive training of the cervical musculature, a physiotherapy treatment regimen, and chiropractic treatment on this patient group. SUMMARY OF BACKGROUND DATA: There are only a few studies involving chronic neck pain patients representative of those seeking care in primary health care centers. Mobilization techniques and intensive training have been shown to be useful, but cervical manipulation has not been assessed. Clinical results involving these commonly used therapies have not been compared. METHODS: A total of 167 consecutive patients were screened. One hundred nineteen patients were admitted to the study and were randomized according to Taves' minimization principles. Primary outcome measures included self-reported pain, disability, medication use, patients' perceived effect, and physician's global assessment. Patients were assessed at enrollment and at completion of the study. Postal questionnaires were used to carry out 4- and 12-month follow-up assessments. Secondary outcome measures included active range of motion of the cervical spine as well as strength and endurance measurements of the cervical musculature. These measurements were carried out at enrollment and completion of the study. RESULTS: A total of 88% of the patients completed the study. Of these, 97% completed the 4-month questionnaire and 93% the 12-month questionnaire. Patients from all three groups demonstrated significant improvements regarding self-reported pain and disability on completion of the study. Improvements were maintained throughout the follow-up period. Medication use was also significantly reduced in all groups. There was, however, no significant difference between groups at any assessment period. Physician's and patients' assessments were also positive, and again group scores were essentially equal. Patients who underwent intensive training demonstrated significantly greater endurance levels at the completion of treatment. CONCLUSIONS: There was no clinical difference between the three treatments. All three treatment interventions demonstrated meaningful improvement in all primary effect parameters. Improvements were maintained at 4- and 12-month follow-up. However, whether this was a result of the treatments or simply a result of time is unknown. Future studies will be necessary to delineate ideal treatment strategies.

Intensive, dynamic back-muscle exercises, conventional physiotherapy, or placebo-control treatment of low-back pain. A randomized, observer-blind trial.

In a randomized, observer-blind trial, 150 men and women, aged 21-64 years, with chronic/subchronic low-back pain, followed one of these three treatment regimens: 1) intensive, dynamic back-muscle exercises; 2) conventional physiotherapy, including isometric exercises for the trunk and leg muscles; and 3) placebo-control treatment involving semihot packs and light traction. Eight treatment sessions were given during the course of 4 weeks, each session lasting 1 hour. The short-term effect was evaluated at the end of the treatment period and 1 month later, and the long-term effect at 6 and 12 months. The evaluations included recording of changes in pain level and assessment of overall treatment effect, which were indicated on visual interval scales. Subgroups of patients could be identified according to their treatment responses: physiotherapy was the superior treatment for the male participants, whereas the intensive back exercises appeared to be most efficient for the female participants. Patients with moderate or hard physical occupations tended toward a better response with physiotherapy, whereas intensive back exercises seemed most effective for those with sedentary/light job functions.

The "Hawthorne effect"--what did the original Hawthorne studies actually show?

The "Hawthorne effect" is often mentioned as a possible explanation for positive results in intervention studies. It is used to cover many phenomena, not only unwitting confounding of variables under study by the study itself, but also behavioral change due to an awareness of being observed, active compliance with the supposed wishes of researchers because of special attention received, or positive response to the stimulus being introduced. At times, the term seems to be used as a social equivalent to "placebo effect". In social research, there is much critical literature indicating that, in general, the term "Hawthorne effect" should be avoided. Instead of referring to the ambiguous and disputable Hawthorne effect when evaluating intervention effectiveness, researchers should introduce specific psychological and social variables that may have affected the outcome under study but were not monitored during the project, along with the possible effect on the observed results.

Spontaneous movements with various seated-workplace adjustments.

Movement patterns in 10 healthy subjects sitting on an office chair with either a tiltable seat, a 5° forwards, or 5° backwards inclining seat were investigated; also the effect of a slanted tabletop desk were studied. The subjects were performing reading and writing tasks. They were investigated twice for one hour on each of two days. Movement pattern was evaluated using counting of movements from videotape recordings of the subjects. Also the subjects' impressions of comfort in the various settings were investigated using a five-point rating scale. The main conclusion is that there exist no significant differences in either the number of movements or in comfort evaluation between the four settings investigated.

Posture, acceptability and energy consumption on a tiltable and a knee-support chair.

Sitting postures on a knee-support (Balans®) chair and a tiltable chair were investigated with 12 healthy subjects during office work and simulated assembly work. After at least 3 weeks' adaptation to each chair, the subjects were investigated for 1 hour on each chair in stratified sequence. Postures were evaluated by means of a statometric method. Spinal load was further estimated by measuring stature shrinkage over each sitting period. Energy consumption was roughly assessed by pulse measurements. Finally, subjective acceptability was rated by a 5-point scale. Posture effects of the Balans® chair, taken in relation to the tiltable chair, were primarily a forward tilt of the pelvis and a change toward lumbar lordosis. Secondly, the trunk was vertical compared to the slightly backward-inclined position in the tiltable chair. The head was most vertical in the Balans® chair. No effect on spinal shrinkage or pulse was observed. The subjective rating seemed to favour the tiltable chair if used over longer periods. However, the Balans(®) chair may be a good alternative for some seated periods and special tasks.

Multidisciplinary intensive treatment for chronic low back pain: a randomized, prospective study.

BACKGROUND: Americans with low back pain have been helped to return to work by multidisciplinary intensive treatment programs. Whether this treatment method will succeed in countries with a more generous social welfare system, where the incentive to return to work might be less, is not proven. OBJECTIVES: To evaluate a Danish program of functional restoration combined with behavioral support. METHODS: Patients who had experienced at least 6 months of disabling low back pain were randomly assigned to either a 3-week intensive treatment program (n = 55) or an untreated control group (n = 51). RESULTS: Of the 106 patients randomized, 94 (89%) returned for a 4-month follow-up visit. At that time, 29 (64%) of the 45 treated patients were able to work, compared with 14 of 49 (29%) in the control group. The treated patients had used fewer days of sick leave (P < .02), had contacted health care. professionals fewer times (P < .001), and had lower pain and disability scores. CONCLUSIONS: Although such programs are expensive, they can reduce pension expenditures, sick leave days, health care contacts, and pain.

How should a seated workplace with a tiltable chair be adjusted?

For a tiltable office chair, subjective height preferences may be different to those for conventional fixed-seat chairs, due to altered biomechanics. These preferences, with a tiltable chair and associated table, have been investigated with a total of 108 subjects. To determine the shortest possible way to obtain reliable height measurements, a study (n = 10) was undertaken. It was demonstrated that two days of measurement seem necessary, the first day involving both a too-high and a too-low start position, the second day only a too-high one. Preferences were measured for each of four groups, one (n = 21) accustomed to and another (n = 35) unaccustomed to a tiltable seat; a third (n = 23) was composed of children and the fourth group (n = 19) was making large-scale drawings. When accustomed to the seat, the subjects preferred a greater seat height. The children's seat-height preference was relatively equal to that of adults, whereas their preferred relative table height was greater, most evidently so with decreasing age. The greatest relative seat height was preferred in connection with large-scale drawings. For desk work it is recommended that the seat height should be approximately 3-5 cm above popliteal height, including shoe heels, and the table height 4-6 cm above the actual elbow height.

Wrist support during typing--a controlled, electromyographic study.

The effects of wrist support on the trapezius and brachial extensor muscle loads during touch-typing were investigated with 12 secretaries, who were suffering pain in one or more of these muscles. They typed for 15 min at each of four experimental situations. The load on the trapezius was significantly greater with wrist support than without, and more marked the higher the support was adjusted. The radial extensor muscle load did not vary significantly. In spite of the higher trapezius load, most of the secretaries preferred a wrist support. Typing performance and body movements, estimated from the movements transferred to a tiltable chair-seat, were both unaffected by wrist support. Whether or not a wrist support should be used for typing cannot be concluded from the present investigation. However, it can be concluded that for touch-typing the keys should be positioned low - probably as low above the thighs as possible.

The distance between the load and the body with three bi-manual lifting techniques.

Studies were made of two different techniques of bi-manual lifting with bent legs (A and B) and a technique of lifting with the back bent and the Knees almost extended (C). With technique A, the trunk was almost vertical, while with B it was erect and more forward inclined and the heel of the front foot kept in contact with the support. Two healthy subject samples (n = 18 and n = 16 respectively) were studied, both employing a force platform; with the second sample the back muscles were also evaluated by electromyography. The distance Delta L between the lines of gravity of the body and the load at the start of the lifts was shortest with technique A and longest with C. This was true whether the position of the feet was chosen spontaneously or was identical for all three techniques. The distance of the load from the body during the lifting movement was directly related to the distance at the start of the lift: the further away the load was at initiation of the lift, the further away it remained throughout the rest of the lift. A request to lift as close to the load as possible had a positive effect in shortening Delta L , but the amount of previously received instruction in lifting technique did not correlate with the spontaneously chosen Delta L.

[Predictive factors of the effect of multidisciplinary, intensive rehabilitation of back pain. Demographic, socioeconomic and physical factors]. / Praediktive faktorer for effekt ved tvaerfaglig, intensiv rygrehabilitering. Demografiske, socioøkonomiske og fysiske faktorer.

In order to identify possible predictive factors for success from rehabilitation in a functional restoration (FR) program for patients with chronic low back pain, pre-treatment baseline variables were correlated to different outcome parameters following treatment in either a FR program or control programs. A prospective clinical trial involving 816 patients was carried out. Of the total cohort 621 patients participated in a FR program and 195 in control groups. The results showed that different factors could be identified as useful in predicting outcome from a FR program, but most of these factors were also shown to predict success for controls of shorter outpatient programs or of no treatment.

[Intensive multidisciplinary treatment of back pain--2 controlled prospective studies]. / Intensiv tvaerfaglig rygbehandling--to kontrollerede, prospektive undersøgelser.

The aim of this study was to evaluate an intensive, multidisciplinary functional restoration program for people with chronic low back pain. The program was compared to a non-treated control group in project A, and to less intensive treatment programs in project B. Both projects were randomized and observer blinded. Two hundred and thirty-eight patients were included, 106 entering project A and 132 project B. All had had chronic low back disability of at least six months duration, with an average of one year's sick leave due to low back pain over the last three years. Their average age was 41 years. The results at follow-up (conducted four months after treatment, follow-up rate 90% in project A and 86% in project B) showed that 67% of the treated patients in project A were able to work compared to 28% in the control group. In project B, 75% of the patients treated in the functional restoration program were able to work, the corresponding numbers from the less intensive programs being 48% and 40%. Numbers of days of sick leave, contacts to the health-care system and pain- and disability-scores were significantly lower for the patients treated in the functional restoration program compared to the other groups in both projects. Functional restoration is more expensive to carry out, but the long-term benefits in form of reductions in pensions, sick leave and contacts to the health-care system, not to mention reduced pain for the patients, seems to justify this expenditure.