Joan Solgaard Sorensen

Magnetic resonance imaging and low back pain in adults: a diagnostic imaging study of 40-year-old men and women.

Study Design. Cross-sectional cohort study of a general population. Objective. To investigate “abnormal” lumbar spine magnetic resonance imaging (MRI) findings, and their prevalence and associations with low back pain (LBP). Summary of Background Data. The clinical relevance of various “abnormal” findings in the lumbar spine is unclear. Distinguishing between inevitable age-related findings and degenerative findings with deleterious consequences is a challenge. Methods. Lumbar spine MRI was obtained in 412, 40-year-old individuals. Predefined “abnormal” MRI findings were interpreted without any knowledge of patient symptoms. Associations between MRI abnormalities and LBP were calculated using odds ratios. The “overall picture” of each MRI finding was established on the basis of the frequencies, diagnostic values, and the strength and consistency of associations. Results. Most “abnormal” MRI findings were found at the lowest lumbar levels. Irregular nucleus shape and reduced disc height were common (>50% of individuals). Relatively common (25% to 50%) were hypointense disc signal, anular tears, high intensity zones, disc protrusions, endplate changes, zygapophyseal joint degeneration, asymmetry, and foraminal stenosis. Nerve root compromise, Modic changes, central spinal stenosis, and anterolisthesis/retrolisthesis were rare (<25%). Most strongly associated with LBP were Modic changes and anterolisthesis (odds ratios >4). Significantly positive associations with all LBP variables were seen for hypointense disc signals, reduced disc height, and Modic changes. All disc “abnormalities” except protrusion were moderately associated with LBP during the past year. Conclusion. Most degenerative disc “abnormalities” were moderately associated with LBP. The strongest associations were noted for Modic changes and anterolisthesis. Further studies are needed to define clinical relevance.

Modic changes and their associations with clinical findings

It is believed that disc degeneration (DD) is, in general, only mildly associated with low back pain (LBP). MRI-identified Modic changes (MC), probably a late stage of DD, are relatively strongly associated with LBP but it is not known if people with MC also have a specific clinical profile. The purpose of this study was to investigate if the clinical findings differ in people with Modic changes (MC) as compared to those with only degenerative disc findings or none at all. In a population-based sample of 412 40-year-old Danes, information was collected independently with MRI, questionnaires and clinical examination. Three subgroups of people were created: those with both DD and MC, those with only DD, and those with neither DD nor MC. The clinical pattern was investigated for each subgroup in order to test the assumption that the clinical picture differs in the three groups. It was expected that people with both DD and MC would have a more pronounced clinical profile than those with only DD who, in turn, would differ from those with neither of these two MRI findings. Our findings were generally in concordance with our expectations. MC constitutes the crucial element in the degenerative process around the disc in relation to LBP, history, and clinical findings. People with DD and no MC only vaguely differ from those without. People with LBP and MC may deserve to be diagnosed as having specific LBP.

Are MRI-defined fat infiltrations in the multifidus muscles associated with low back pain?

BackgroundBecause training of the lumbar muscles is a commonly recommended intervention in low back pain (LBP), it is important to clarify whether lumbar muscle atrophy is related to LBP. Fat infiltration seems to be a late stage of muscular degeneration, and can be measured in a non-invasive manner using magnetic resonance imaging. The purpose of this study was to investigate if fat infiltration in the lumbar multifidus muscles (LMM) is associated with LBP in adults and adolescents.MethodsIn total, 412 adults (40-year-olds) and 442 adolescents (13-year-olds) from the general Danish population participated in this cross-sectional cohort study. People with LBP were identified through questionnaires. Using MRI, fat infiltration of the LMM was visually graded as none, slight or severe. Odds ratios were calculated for both age groups, taking into account sex, body composition and leisure time physical activity for both groups, and physical workload (in adults only) or daily bicycling (in adolescents only).ResultsFat infiltration was noted in 81% of the adults but only 14% of the adolescents. In the adults, severe fat infiltration was strongly associated with ever having had LBP (OR 9.2; 95% CI 2.0–43.2), and with having LBP in the past year (OR 4.1; 1.5–11.2), but there was no such association in adolescents. None of the investigated moderating factors had an obvious effect on the OR in the adults.ConclusionFat infiltration in the LMM is strongly associated with LBP in adults only. However, it will be necessary to quantify these measurements objectively and to investigate the direction of this link longitudinally in order to determine if the abnormal muscle is the cause of LBP or vice versa.

An epidemiologic study of MRI and low back pain in 13-year-old children.

Study Design. Cross-sectional cohort study of a general population. Objective. To describe associations between “abnormal” lumbar magnetic resonance imaging (MRI) findings and low back pain (LBP) in 13-year old children. Summary and Background Data. Very little is known about the distribution of lumbar MRI findings and how they are associated with LBP in youngsters. Methods. Disc abnormalities, as well as nerve root compromise, endplate changes, and anterolisthesis were identified from MRI studies of 439 children. LBP was identified from structured interviews. Associations are presented as odds ratios (OR). Results. Signs of disc degeneration were noted in approximately 1/3 of the subjects. Reduced signal intensity and irregular nucleus shape in the upper 3 lumbar discs were significantly associated with LBP within the last month (OR, 2.5–3.6), whereas reduced signal intensity and disc protrusion at L5–NS1 were associated with seeking care (OR, 2.8 and 7.7, respectively). Endplate changes in relation to the L3 discs were associated with LBP month and seeking care (OR, between 9.7 and 22.2). Anterolisthesis at L5 was associated with seeking care (OR, 4.3). There were obvious differences between genders: degenerative disc changes in the upper lumbar spine were more strongly associated with LBP in boys, while disc abnormalities in the lower lumbar spine were more strongly associated with seeking care in girls. Conclusions. In children, degenerative disc findings are relatively common, and some are associated with LBP. There appears to be a gender difference. Disc protrusions, endplate changes, and anterolisthesis in the lumbar spine were strongly associated with seeking care for LBP.

The effect of body position and axial load on spinal canal morphology: an MRI study of central spinal stenosis.

Study Design. A method comparison study. Objective. To investigate the effect of body position and axial load of the lumbar spine on disc height, lumbar lordosis, and dural sac cross-sectional area (DCSA). Summary of Background Data. The effects of flexion and extension on spinal canal diameters and DCSA are well documented. However, the effects of axial loading, achieved by upright standing or by a compression device, are still unclear. Methods. Patients with lumbar spinal stenosis were examined in 2 separate studies, including 16 and 20 patients, respectively. In section 1, magnetic resonance imaging (MRI) scans were performed during upright standing and supine positions with and without axial load. In section 2, MRI scans were performed exclusively in supine positions, one with flexion of the lumbar spine (psoas-relaxed position), an extended position (legs straight), and an extended position with applied axial loading. Disc height, lumbar lordosis, and DCSA were measured and the different positions were compared. Results. In section 1, the only significant difference between positions was a reduced lumbar lordosis during standing when compared with lying (P = 0.04), most probably a consequence of precautions taken to secure immobility during the vertical scans. This seemingly makes our standing posture less valuable as a standard of reference. In section 2, DCSA was reduced at all 5 lumbar levels after extension, and further reduced at 2 levels after adding compression (P < 0.05). Significant reductions of disc height were found at 3 motion segments and of DCSA at 11 segments after compression, but these changes were never seen in the same motion segment. Conclusion. Horizontal MRI with the patient supine and the legs straightened was comparable to vertical MRI whether axial compression was added or not. Extensionwas the dominant cause rather than compression in reducing DCSA. Axial load was not considered to have a clinically relevant effect on spinal canal diameters.

Intra- and Interobserver Reproducibility of Vertebral Endplate Signal (Modic) Changes in the Lumbar Spine: The Nordic Modic Consensus Group Classification

Background: The lumbar vertebral endplate is considered a potential cause of specific low back pain. However, in relation to future research, there is need for a reliable and detailed magnetic resonance imaging (MRI) protocol to be used in the evaluation of vertebral endplate signal changes. Purpose: To assess the intra- and interobserver reliability of the “Nordic Modic classification” protocol. Material and Methods: MRI scans of 50 individuals representative of the general Danish population aged 40 were evaluated by two observers. Criteria for grading the changes were developed by the Nordic Modic Consensus Group. After consensus was established, all 50 MRI examinations were evaluated independently by each observer. Intraobserver reliability was assessed by re-evaluation of the 50 examinations by one of the observers. Kappa statistics were used to calculate agreement. Results: Intra- and interobserver agreement of the evaluation of variables describing vertebral signal changes, i.e. Modic type, location, volume, maximum height, and endplate area, were all found to have substantial to almost perfect agreement. The evaluation of osteophytes was found to be reliable, whereas the evaluation of localized endplate defects and irregular endplates had only moderate agreement. The evaluation of development over time was found to have substantial intraobserver agreement but only moderate interobserver agreement. As expected, intraobserver agreement was generally better than interobserver agreement. Conclusion: In this study, we found convincing reproducibility of a detailed evaluation protocol of vertebral endplate signal changes, the “Nordic Modic Classification.” The authors recommend that the evaluation protocol should be used in future studies investigating vertebral endplate signal changes.

Characteristics and natural course of vertebral endplate signal (Modic) changes in the Danish general population

BackgroundVertebral endplate signal changes (VESC) are more common among patients with low back pain (LBP) and/or sciatica than in people who are not seeking care for back pain. The distribution and characteristics of VESC have been described in people from clinical and non-clinical populations. However, while the clinical course of VESC has been studied in patients, the natural course in the general population has not been reported. The objectives of this prospective observational study were to describe: 1) the distribution and characteristics of VESC in the lumbar spine, 2) its association with disc degeneration, and 3) its natural course from 40 to 44 years of age.MethodsThree-hundred-and-forty-four individuals (161 men and 183 women) sampled from the Danish general population had MRI at the age of 40 and again at the age of 44. The following MRI findings were evaluated using standardised evaluation protocols: type, location, and size of VESC, disc signal, and disc height. Characteristics and distribution of VESC were analysed by frequency tables. The association between VESC and disc degeneration was analysed by logistic regression analysis. The change in type and size of VESC was analysed by cross-tabulations of variables obtained at age 40 and 44 and tested using McNemars test of symmetry.ResultsTwo-thirds (67%) of VESC found in this study were located in the lower part of the spine (L4-S1). VESC located at disc levels L1-L3 were generally small and located only in the anterior part of the vertebra, whereas those located at disc levels L4-S1 were more likely to extend further into the vertebra and along the endplate. Moreover, the more the VESC extended into the vertebra, the more likely it was that the adjacent disc was degenerated. The prevalence of endplate levels with VESC increased significantly from 6% to 9% from age 40 to 44. Again, VESC that was only observed in the endplate was more likely to come and go over the four-year period compared with those which extended further into the vertebra, where it generally persisted.ConclusionThe prevalence of VESC increased significantly over the four-year period. Furthermore, the results from this study indicate that the distribution of VESC, its association with disc degeneration and its natural course, is dependent on the size of the signal changes.

Antibiotic treatment in patients with low-back pain associated with Modic changes Type 1 (bone oedema): a pilot study

Objective: The aim of this study was to assess the clinical effect of antibiotic treatment in a cohort of patients with low-back pain (LBP) and Modic changes Type 1 (bone oedema) following a lumbar herniated disc. Design: This was a prospective uncontrolled trial of 32 LBP patients who had Modic changes and were treated with Amoxicillin-clavulanate (500 mg/125 mg) 3 × day for 90 days. All patients had previously participated in a randomised controlled trial (RCT) that investigated active conservative treatment for a lumbar herniated disc (n = 166). All patients in that RCT who had Modic changes and LBP at 14 months follow-up (n = 37) were invited to participate in this subsequent antibiotic trial but five did not meet the inclusion criteria. Results: 29 patients completed the treatment, as three patients dropped out due to severe diarrhoea. At the end of treatment and at long-term follow-up (mean 10.8 months) there was both clinically important and statistically significant (p⩽0.001) improvement in all outcome measures: LBP intensity, number of days with pain, disease-specific and patient-specific function, and global perceived effect. Conclusions: In this uncontrolled trial, the clinical effect of antibiotic treatment was large in a group of patients with Modic changes suffering from persistent LBP following a disc herniation. These results provide tentative support for a hypothesis that bacterial infection may play a role in LBP with Modic changes and indicate the need for randomised controlled trials to test this hypothesis.

Lumbar modic changes-a comparison between findings at low- and high-field magnetic resonance imaging

Study Design. A cross-sectional observational study. Objective. To investigate whether there is a difference in findings of lumbar Modic changes in low-field (0.3 T) magnetic resonance imaging (MRI) compared with high-field (1.5 T). Summary of Background Data. It is a challenge to give patients with low back pain a specific diagnosis. Modic changes as seen on MRI have been reported to be a possible source of pain. However, it is unclear whether the diagnosis is independent on the field strength. Methods. Twenty patients with Modic changes, 11 women and 9 men (mean age, 53.6 yr; range, 29–81 yr), with or without sciatica, seen in a Danish outpatient low back pain clinic were included. All patients obtained MRI scans on both a high-field and a low-field MRI scanner. Two radiologists evaluated all lumbar endplates independently, using a standardized evaluation protocol. Kappa statistics were used to analyze the interobserver reproducibility. We used paired t test to analyze the difference between low- and high-field MRI. Results. The total number of Modic changes diagnosed with high-field MRI was significantly higher than that with low-field MRI. However, 3 to 4 times as many Modic type 1 changes were found with low-field MRI compared with high-field MRI. Contrarily, with high-field MRI type 2 changes were diagnosed twice as often. Conclusion. There was a significant difference between low- and high-field MRI regarding the overall prevalence of any Modic change, but this had opposite directions for types 1 and 2: type 2 dominated in low field and conversely in high field. The type of MRI unit should be taken into consideration when diagnosing patients with Modic changes.

Type 1 Modic changes was a significant risk factor for 1-year outcome in sick-listed low back pain patients: a nested cohort study using magnetic resonance imaging of the lumbar spine.

BACKGROUND CONTEXT It is not clear whether Modic changes (MC) is associated with low back pain (LBP) outcome. PURPOSE To study associations between baseline degenerative manifestations and outcome in sick-listed LBP patients. STUDY DESIGN Prospective nested cohort study based on a randomized controlled trial. PATIENT SAMPLE Out of 325 sick-listed LBP patients, 141 were consecutively examined by magnetic resonance imaging (MRI) and included and 140 completed the study. OUTCOME MEASURES Degenerative manifestations of the lumbar spine were quantified; associations were studied in relation to the three primary outcomes: change of back+leg pain, change of function as measured by Roland-Morris questionnaire, and 1-year unsuccessful return to work (U-RTW). METHODS By using a previously validated MRI protocol, a specialist in radiology, who had no access to clinical data, described the images. Associations were studied by linear and logistic regression with adjustment for previously identified prognostic factors for 1-year pain and function and for U-RTW. RESULTS Clinically, 43% of the patients had radiculopathy. Degenerative changes were prevalent with altered disc contours in 84%, high-intensity zones in 70%, and nerve root touch or impingement in 63% of the patients. MC was identified in 60% of the patients, 18% with Type 1 changes and 42% with Type 2 changes, Type 1 including both Type 1 and Type 1 in combination with Type 2. Patients with Type 1 changes reported more back pain and did not improve in pain or disability. They increased to include 30% of the patients with U-RTW at 1 year. Patients with Type 2 changes did not differ significantly from patients without MC but differed significantly from patients with Type 1 changes in all three outcomes. Other degenerative manifestations were not significantly associated with any of the three outcomes. CONCLUSIONS The only degenerative manifestation negatively associated with outcome was Type 1 MC that affected 18% of the cohort at baseline and implied an increased risk for no improvement in pain and function and for U-RTW, even after adjustment for other prognostic factors.