The effect of the stay active advice on physical activity and on the course of acute severe low back pain.

BACKGROUND: Disability due to acute low back pain (ALBP) runs parallel with distress and physical inactivity. If low back pain persists, this may lead to long-term sick leave and chronic back pain. This prospective randomized study evaluated the effect on physical activity and on the course of ALBP of two different treatment advices provided in routine care. METHODS: Ninety-nine patients with acute severe LBP examined within 48 h after pain onset were randomized to the treatment advices "Stay active in spite of pain" (stay active group) or "Adjust activity to the pain" (adjust activity group). Pedometer step count and pain intensity (Numeric Rating Scale, NRS, 0-10) were followed daily during seven days. Linear mixed modeling were employed for statistical analyses. RESULTS: The step count change trajectory showed a curvilinear shape with a steep initial increase reaching a plateau after day 3 in both groups, followed by an additional increase to day 7 in the stay active group only. At day 1, the step count was 4560 in the stay active group compared to 4317 in adjust activity group (p = 0.76). Although there were no statistical differences between the two groups in the parameters describing the change trajectory for step count, the increase in step count was larger in the stay active group. At day 7 the step count was 9865 in the stay active group compared to 6609 in the adjust activity group (p = 0.008). The pain intensity (NRS) trajectory was similar in the two groups. Between day 1 and day 7 it decreased linearly from 5.0 to 2.8 in the stay active group (p < 0.001), and from 4.8 to 2.3 in the adjust activity group (p < 0.001). CONCLUSIONS: Patients with acute severe LBP advised to stay active in spite of the pain exhibited a considerable more active behavior compared to patients adjusting their activity to pain. This result confirms compliance to the treatment advice as well as the utility of the stay active advice to promote additional physical activity for more health benefits in patients with ALBP. There was minimal effect of the treatment advice on the course of ALBP. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02517762).

Comparison between pain at discography and morphological disc changes at axial loaded MRI in patients with low back pain.

PURPOSE: Discogenic pain is induced by axial load, but there are no studies evaluating the influence of dynamic MRI in relation to provoked pain at discography. The aim of this study was to investigate the relationship between discography-induced pain and morphological disc changes, occurring during axial loaded MRI (alMRI). A secondary aim was to compare and register the frequency of provoked concordant pain at alMRI and discography. METHODS: 41 patients with assumed discogenic pain were investigated with MRI, alMRI and pressure-controlled discography (PCD) (119 discs). Provoked pain at both discography and alMRI was classified as concordant or discordant with daily pain as reference. A concordant discogram required pain intensity ≥5/10 (numerical rating scale) at ≤50 psi and one negative control disc. A concordant provocation at alMRI required pain intensity ≥5/10. The relationship between concordant pain at discography and morphological disc measures (degeneration, height, bulge, angle, area, and circumference) at MRI/alMRI was investigated. RESULTS: Changes in the morphological appearance occurred in at least one disc level in all patients when loaded and unloaded MRI were compared. However, no significant differences between concordant and discordant discograms in terms of morphological disc features at conventional MRI or alMRI were found. 78 % of the patients reported concordant provoked pain during the alMRI. CONCLUSIONS: In the majority of patients with low back pain, discography as well as alMRI provoked concordant pain. Loading of the spine, alMRI, revealed however no clinically useful morphological characteristics in the discs with concordant discograms. Alternative or more sensitive diagnostic methods are needed to understand load-induced discogenic pain.

Pressure Increase in Adjacent Discs During Clinical Discography Questions the Methods Validity.

STUDY DESIGN: Observational in vivo clinical study. OBJECTIVE: To investigate whether intradiscal pressure is transferred to adjacent discs during clinical discography in subjects with discogenic pain. SUMMARY OF BACKGROUND DATA: Despite the introduction of pressure registration in discography, the validity of the method remains controversial. Discography in vivo in anesthetized pigs has shown that the pressure increase during disc injection is transmitted to adjacent discs. If pressure transmission is confirmed in human spines, it could be a potential source of false-positive discography responses. METHODS: Twenty-five discograms were performed in 9 consecutive patients. A pressure sensor was introduced through a 22-gauge needle into the nucleus pulposus in 2 adjacent discs. Contrast was injected with a manometer (∼0.05 mL/s) into one of the discs, whereas intradiscal pressure was measured simultaneously in both discs. The injection continued until one of the endpoints was reached; concordant pain with an intensity of 5/10 or more, intradiscal pressure of 80 psi (absolute pressure), and/or 3.5-mL contrast volume. RESULTS: Intradiscal pressure was successfully measured in 22 adjacent discs of which 7 were not filled with contrast and 15 were prefilled from the previous discogram. A mean pressure increase of 13 psi (range, 3-42 psi) was recorded in 55% (12) of the adjacent discs, corresponding to an increase of 62% above baseline. Of discograms inducing pressure transmission, all had Pfirrmann degeneration grade of 3 or more and, of adjacent discs with increased pressure, 75% had degeneration of 3 or more. Maximum pressure in injected discs averaged 35 psi above opening pressure (range, 10-69 psi). CONCLUSION: Clinical discography induces a pressure increase in adjacent discs. The induced pressure increase was of a clinically relevant magnitude and was evident despite low absolute pressures in the injected disc. Pressure transmission during discography constitutes a potential major source of false-positive responses, questioning the ability of discography to provoke pain at just a single disc level. LEVEL OF EVIDENCE: 1.

In vivo discography in degenerate porcine spines revealed pressure transfer to adjacent discs.

STUDY DESIGN: In vivo experimental porcine study. OBJECTIVE: To investigate if discography induced pressure increase in adjacent degenerate discs. SUMMARY OF BACKGROUND DATA: Despite refinements in the past 2 decades, the validity of discography is debated. Discography in healthy pigs has shown that the pressure increase during disc injection transmits to adjacent discs, a potential source for false positive responses. METHODS: Degeneration in 1 lumbar disc was induced in 10 pigs by drilling a hole through the endplate. Intradiscal pressure was recorded using a 0.36-mm fiber-optic pressure transducer inserted into nucleus pulposus through a 22-gauge needle. The pressure was measured simultaneously in 2 adjacent discs during slow (0.03 mL/s) automated contrast injection into 1 of the discs up to 8 bar (116 psi). Ten adjacent discs were prefilled with contrast from previous discogram. A pressure increase 2 psi or more above baseline was defined as increased pressure in adjacent discs. Pressure was recorded until 15 minutes after injection. RESULTS: A total of 28 discograms were successfully performed. A pressure increase during injection was detected in 57% (16) of the 28 adjacent discs with mean 3.2 psi (1.7-8.2; standard deviation, 1.8), corresponding to a mean increase above baseline of 11%. Of those 16 adjacent discs, 4 were nondegenerate and 12 degenerate, of which 7 were prefilled. Fifteen minutes after injection, 89% of adjacent discs displayed increase in pressure of mean 14% above baseline. CONCLUSION: Discography induced pressure increase in adjacent discs in a degenerate disc model, something not reported earlier. If present, also in human spine pressure transmission, may be a potential cause for false positive discography responses.

HIZ's relation to axial load and low back pain: investigated with axial loaded MRI and pressure controlled discography.

PURPOSE: The aims were to investigate if the detection of high-intensity zones (HIZ) is affected by axial load, and to study the correlation between HIZ and discogenic pain provoked with pressure controlled discography (PCD). METHODS: 41 consecutive patients with chronic low back pain, referred for discography, were included. Each patient underwent PCD, CT, MRI, and axial loaded MRI (alMRI) within 24 h. 35 patients completed all MRI sequences (140 discs). The detection of HIZ was compared between conventional MRI and alMRI. PCD was performed in 119 of the discs examined at MRI. Provoked pain at PCD was classified into four categories (none/unfamiliar/similar/exact), with the patients' daily pain as reference, and correlated with presence of HIZ. RESULTS: AlMRI did not affect the detection of HIZ compared with conventional MRI. No significant correlation between HIZ and the 4-graded pain response at discography was found (p = 0.34), neither when combining similarly/exactly reproduced pain (p = 0.08). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of HIZ in detecting discs with exactly reproduced pain were 49, 69, 39 and 76 %. When combining similarly/exactly reproduced pain, PPV was higher but still only 70 %. CONCLUSIONS: The detection of HIZ was not influenced by axial load. With strict PCD, discogenic pain can neither be confirmed when having HIZ (PPV 39 %) nor ruled out in discs without HIZ (NPV 76 %). Larger PCD studies including quantification of HIZ at conventional and alMRI are needed, before any dynamic component affected by axial load can be ruled out completely.

The transfer of disc pressure to adjacent discs in discography: a specificity problem?

STUDY DESIGN: In vivo experimental study. OBJECTIVE: The primary objective of the study was to investigate pressure transmission to adjacent discs during discography. A secondary objective was to quantify the transmitted pressure, both in contrast injected and noninjected porcine intervertebral discs. SUMMARY OF BACKGROUND DATA: Discography is used to before surgery identify painful discs. A pain response during discography that is concordant with the patient's experienced back pain is regarded as an indication that the injected disc is the source of pain. However, the sensitivity and specificity of discography are matters of debate. Pressure-controlled discographies have been reported to reduce the number of false-positive discs using low pressure criteria. Preliminary data indicated a transfer of pressure from an injected to an adjacent disc during discography. Pressure transmission in vivo during lumbar discography, not reported before might, if clinically present, contribute to a false-positive diagnosis. METHODS: Thirty-six lumbar discs in 9 adolescent pigs were investigated. Intradiscal pressure was recorded during contrast injection, using a 0.36/0.25 mm fiber-optic pressure transducer inserted into the nucleus pulposus via a 22 G needle. The pressure was measured simultaneously in 2 adjacent discs during contrast injection into 1 of the discs at pressures up to 8 bar. Transmitted pressure was recorded both in noninjected discs and in discs that were prefilled with contrast. RESULTS: Thirty-three discs were successfully examined. During contrast injection, there was an intradiscal pressure rise in the adjacent disc with a median value of 16.0% (range, 3.2-37.0) over baseline pressure. There was no significant difference in pressure increase between the noninjected and prefilled discs (P < 0.68). CONCLUSION: Discography of porcine discs induces a pressure increase in adjacent discs. A similar pressure transfer during human clinical discography might elicit false-positive pain reactions.

Previous vertebral compression fractures add to the deterioration of the disability and quality of life after an acute compression fracture.

Prevalent vertebral compression fracture(s) have been reported as having a negative impact on pain, disability, and quality of life. But no study has evaluated the effect of previous fracture on the course of acute compression fractures. The aim of the present study was to compare the natural course of the acute compression fracture in patients with (n = 51) and without (n = 56) previous vertebral compression fracture(s). The study is a retrospective analysis of a prospective cohort followed with postal questionnaires during a 12-month period after an acute fracture event. Eligible patients were those over 40 years of age, who were admitted to the emergency unit because of back pain and had an X-ray confirmed acute vertebral body fracture. A total of 107 patients were included in the study. The pain, disability (von Korff pain and disability scores), ADL (Hannover ADL score), and quality of life (QoL) (EQ-5D) were measured after 3 weeks, and 3, 6, and 12 months. The X-rays from the first visit to the emergency unit were evaluated. The difference of the scores between the groups with and without previous fracture was statistically significant (P < 0.05) at 3 weeks, 6 and 12 months for von Korff disability score, at all occasions for EQ-5D and at 3-12 months for Hannover ADL score, but only at 12 months for the von Korff pain intensity score. In both the groups all scores had improved in a statistically significant way at 3 months. The number of previous fractures was related to all the outcome scores in a statistically significant way (P < 0.05) except von Korff pain intensity score at 3 weeks and 3 months and von Korff disability score at 3 months. In conclusion, disability, ADL, and QoL scores, but not pain intensity score, were significantly worse in the patients with previous fracture from the fracture episode through the first 12 months. However, the improvements during the follow-up year seen in both groups were of a similar magnitude. The presence or absence of a previous fracture in an acutely fractured patient will influence the prognosis and thus possibly also the indications for treatments.

Bulging of the inner and outer annulus during in vivo axial loading of normal and degenerated discs.

STUDY DESIGN: Comparison of in vivo biomechanical outcomes between experimental and control group animals. OBJECTIVE: To quantify the in vivo bulging response of the inner and outer annulus in animals with and without disc degeneration. SUMMARY OF BACKGROUND DATA: Prior attempts to quantify the load-deformation response of the inner annulus have most often relied on in vitro preparations. Unfortunately, to visualize the inner annulus, these in vitro approaches rely on disc modifications that may result in nonphysiologic behaviors. In response to this problem, in vivo techniques were developed to quantify regional bulging of the inner and outer annulus during applied axial loading. METHODS: Two groups of pigs were tested: a normal group and a group having disc degeneration that was induced surgically 3 months earlier. Eight adolescent pigs were evaluated and for each animal, a miniature servohydraulic actuator was attached to the third and fourth lumbar vertebrae to deliver a cyclic axial loading protocol (300 N, 1 Hz, 10 cycles) whereas regional deformations of the annulus were visualized ultrasonically via retroperitoneal access. RESULTS: For the normal animals, image analysis demonstrated a significantly greater bulging of the inner annular region when compared with the outer annular region. In animals with disc degeneration, the inner and outer annular regions were equal in their bulging response, which ranged from 0 bulging to 37% greater than the average response of the normal animals. CONCLUSIONS: This work supports prior in vitro studies that observed maximal disc bulging in the inner annulus and minimal bulging in the external annulus. Results for this in vivo study suggest that this normal bulging gradient is lost with degenerative disc disease. Compared with in vitro approaches, this new in vivo technique has the potential to demonstrate disc behavior in a variety of loading conditions and/or with a variety of induced disc pathologies.

The narrowing of the lumbar spinal canal during loaded MRI: the effects of the disc and ligamentum flavum.

Load and activity changes of the spine typically cause symptoms of nerve root compression in subjects with spinal stenosis. Protrusion of the intervertebral disc has been regarded as the main cause of the compression. The objective was to determine the changes in the size of the lumbar spinal canal and especially those caused by the ligamentum flavum and the disc during loaded MRI. For this purpose an interventional clinical study on consecutive patients was made. The lumbar spines in 24 supine patients were examined with MRI: first without any external load and then with an axial load corresponding to half the body weight. The effect of the load was determined through the cross-sectional areas of the spinal canal and the ligamentum flavum, the thickness of ligamentum flavum, the posterior bulge of the disc and the intervertebral angle. External load decreased the size of the spinal canal. Bulging of the ligamentum flavum contributed to between 50 and 85% of the spinal canal narrowing. It was concluded that the ligamentum flavum, not the disc had a dominating role for the load induced narrowing of the lumbar spinal canal, a finding that can improve the understanding of the patho-physiology in spinal stenosis.

The prognosis for pain, disability, activities of daily living and quality of life after an acute osteoporotic vertebral body fracture: its relation to fracture level, type of fracture and grade of fracture deformation.

The level of the acute osteoporotic vertebral fracture, fracture type and grade of fracture deformation were determined in 107 consecutive patients and related to pain, disability, activities of daily living (ADL) and quality of life (QoL) after 3 weeks, 3, 6 and 12 months. Two-thirds of the fractured patients were women and with a similar average age, around 75 years, as the men. Fifty-eight of the acute fractures were located in the thoracic spine and 49 in the lumbar spine and predominantly at the Th12 and L1 levels. Sixty-nine percent of the fractures were wedge, 19% concave and 12% crush fractures. There were 22 mildly, 50 moderately and 35 severely deformed vertebrae. The grade of fracture deformation was not related to gender, age or fracture location. Severely deformed vertebrae predominantly (92%) occurred among the crush fracture type. One year after the fracture, irrespective of fracture level, fracture type or grade of fracture deformation, 4/5 still had pronounced pain and deteriorated QoL. Initial severe fracture deformation by far was the worst prognostic factor for severe lasting pain and disability, and deterioration of ADL and QoL. Factors like fracture level, lumbar fractures tended to improve steadily while thoracic deteriorated, type of fracture, the wedge and concave resulting in less pain and better QoL than the crush fracture type and gender influenced to a lesser extent the outcomes during the year after the acute fracture.

Utility of spine surgery: a comparison of common elective orthopaedic surgical procedures.

STUDY DESIGN: A 1-year prospective observational cohort study. OBJECTIVE: To compare the utility before and 1 year after elective spine surgery with some other common orthopaedic surgical procedures. SUMMARY OF BACKGROUND DATA: By using global measures like EQ-5D and SF-36 for the determination of the utility, the changes in quality of life, quality of life (QoL) after an intervention different diagnoses, and treatments can be compared. Total hip replacement (THR) has become almost golden standard in this respect. METHODS: Seven hundred seventy-seven subjects with different common orthopaedic diagnoses scheduled for elective surgery were just before surgery and 1 year after surgery answering both EQ-5D and SF-36. Four groups with different spine diagnoses and procedures were formed and compared with 8 other diagnoses and treatment groups. RESULTS: Before surgery, subjects with spine diagnoses reported the lowest QoL of all diagnoses compared. Surgery for spinal stenosis, spondylolisthesis, and instability meant the largest improvement of all surgical interventions. Surgery for NHP gave a moderately good improvement, whereas surgery for CLBP only marginally improved those operated. Particularly THR but also TKR more or less completely normalized QoL but made it from a relatively high preoperative level. The greatest improvements after spine surgery, other surgical procedures, and different diagnoses were in the pain/discomfort domain. CONCLUSION: Spinal surgery in spinal stenosis, spondylolisthesis, and instability had in comparison to other types of elective orthopaedic surgery an outstanding better ability to improve the operated subject's health-related quality of life than other types of elective orthopaedic surgery. The utility of HNP surgery was somewhat lower and was rather marginal for those operated for nonspecific CLBP.

The course of the acute vertebral body fragility fracture: its effect on pain, disability and quality of life during 12 months.

The vertebral body fracture is the most frequent bone fragility fracture. In spite of this there is considerable uncertainty about the frequency, extent and severity of the acute pain and even more about the duration of pain, the magnitude of disability and how much daily life is disturbed in the post-fracture period. The aim of the present study was to follow the course of pain, disability, ADL and QoL in patients during the year after an acute low energy vertebral body fracture. The study design was a longitudinal cohort study with prospective data collection. All the patients over 40 years admitted to the emergency unit because of back pain with a radiologically acute vertebral body fracture were eligible. A total of 107 patients were followed for a year. The pain, disability (von Korff pain and disability scores), ADL (Hannover ADL score), and QoL (EQ-5D) were measured after 3 weeks, 3, 6 and 12 months. Two-thirds of the patients were women, and were similar in average age, as the men around 75 years. A total of 65.4% of the fractures were due to a level fall or a minor trauma, whereas 34.6% had no recollection of trauma or a specific event as the cause of the fracture. A total of 76.6% of the fractured patients were immediately mobilized and allowed to return home while the remaining were hospitalized. The average pain intensity score after 3 weeks was 70.9 (SD 19.3), the disability score 68.9 (SD 23.6), the ADL score 37.7 (SD 22.1) and EQ-5D score of 0.37 (SD 0.37). The largest improvements, 10-15%, occurred between the initial visit and the 3 months follow-up and were quite similar for all the measures. From 3 months, all the outcome measures leveled out or tended to deteriorate resulting in a mean pain intensity score of 60.5, disability score of 53.9, ADL score of 47.6, and EQ-5D score 0.52 after 12 months. After a whole year the fractured patients' condition was similar to the preoperative condition of patients with a herniated lumbar disc, central lumbar spinal stenosis or in patients 100% work disabled due to back or neck problems. Instead of the generally believed good prognosis for the greater majority of those fractured, the acute vertebral body fracture was the beginning of a long-lasting severe deterioration of their health.

The relationship between the cross-sectional area of the cauda equina and the preoperative symptoms in central lumbar spinal stenosis.

STUDY DESIGN: A cross-sectional registry and imaging cohort study. OBJECTIVES: To study the association between typical symptoms and signs of central spinal stenosis and the minimum cross-sectional area (mCSA) of the cauda equina in patients subsequently undergoing surgery. SUMMARY OF BACKGROUND DATA: Relations between mCSA and the symptoms of spinal stenosis have not been studied before. SUBJECTS AND METHODS: The preoperative walking ability, pain in the leg(s) and back, duration of symptoms and quality of life in 82 men and women subsequently operated for spinal stenosis were related to the digitally determined CSA of the single most constricted level, mCSA of their lumbar spines. RESULTS: A smaller mCSA was directly related to a shorter walking distance before claudication. A small mCSA meant more leg and back pain and a lower health-related quality of life. For those with a walking ability <100 m, the average mCSA was around 53 mm; whereas it was just <69 mm for those able to walk >500 m. The average mCSA did not differ depending on gender, age, or vertebral level. CONCLUSIONS: The mCSA was a strong predictor of the preoperative walking ability, leg and back pain, and was directly related to the quality of life of patients with central spinal stenosis.

The cost-utility of lumbar disc herniation surgery.

The cost and utility of surgery for a herniated lumbar disc has not been determined simultaneously in a single cohort. The aim of this study is to perform a cost-utility analysis of surgical and nonsurgical treatment of patients with lumbar disc herniation. Ninety-two individuals in a cohort of 1,146 Swedish subjects underwent lumbar disc herniation surgery during a 2-year study. Each person operated on was individually matched with one treated conservatively. The effects and costs of the treatments were determined individually. By estimating quality of life before and after the treatment, the number of quality adjusted life years (QALY) gained with and without surgery was calculated. The medical costs were much higher for surgical treatment; however, the total costs, including disability costs, were lower among those treated surgically. Surgery meant fewer recurrences and less permanent disability benefits. The gain in QALY was ten times higher among those operated. Lower total costs and better utility resulted in a better cost utility for surgical treatment. Surgery for lumbar disc herniation was cost-effective. The total costs for surgery were lower due to lower recurrence rates and fewer disability benefits, and surgery improved quality of life much more than nonsurgical treatments.

Rapid atrophy of the lumbar multifidus follows experimental disc or nerve root injury.

STUDY DESIGN: Experimental study of muscle changes after lumbar spinal injury. OBJECTIVES: To investigate effects of intervertebral disc and nerve root lesions on cross-sectional area, histology and chemistry of porcine lumbar multifidus. SUMMARY OF BACKGROUND DATA: The multifidus cross-sectional area is reduced in acute and chronic low back pain. Although chronic changes are widespread, acute changes at 1 segment are identified within days of injury. It is uncertain whether changes precede or follow injury, or what is the mechanism. METHODS: The multifidus cross-sectional area was measured in 21 pigs from L1 to S1 with ultrasound before and 3 or 6 days after lesions: incision into L3-L4 disc, medial branch transection of the L3 dorsal ramus, and a sham procedure. Samples from L3 to L5 were studied histologically and chemically. RESULTS: The multifidus cross-sectional area was reduced at L4 ipsilateral to disc lesion but at L4-L6 after nerve lesion. There was no change after sham or on the opposite side. Water and lactate were reduced bilaterally after disc lesion and ipsilateral to nerve lesion. Histology revealed enlargement of adipocytes and clustering of myofibers at multiple levels after disc and nerve lesions. CONCLUSIONS: These data resolve the controversy that the multifidus cross-sectional area reduces rapidly after lumbar injury. Changes after disc lesion affect 1 level with a different distribution to denervation. Such changes may be due to disuse following reflex inhibitory mechanisms.

Prevalence of low back pain and sickness absence: a "borderline" study in Norway and Sweden.

AIMS: Low back pain (LBP) is a major public health problem in both Norway and Sweden. The aim of the study was to estimate the prevalence of LBP and sickness absence due to LBP in two neighbouring regions in Norway and Sweden. The two areas have similar socioeconomic status, but differ in health benefit systems. METHODS: A representative sample of 1,988 adults in Norway and 2,006 in Sweden completed questionnaires concerning LBP during 1999 and 2000. For this study only individuals in part or full time jobs, (n = 1,158 in Norway and n = 1,129 in Sweden) were included. RESULTS: In Norway the lifetime prevalence was 60.7% and in Sweden 69.6%, the one-year prevalence was 40.5% and 47.2%, and the point prevalence 13.4% and 18.2% respectively. There was a significantly higher risk of reporting LBP in Sweden, even after controlling for gender, age, education, and physical workload. There was no difference in risk of self-certified short-term sickness absence (1-3 days), but it was a 40% lower risk of sickness absence with medical sickness certification in Sweden compared with Norway. CONCLUSION: The prevalence of LBP was higher in the Swedish area than in the Norwegian. The risk of self-certified sickness absence, however, showed no differences and the risk of medically certified sickness absence was lower in the Swedish area. This contradiction might partly be explained by the economical "disincentives" in the Swedish health compensation system.