Bone Marrow Edema Of Sacroiliac Joints Research Articles

Dissociation of clinical symptoms and magnetic resonance imaging data in axial psoriatic arthritis

Currently, there is no generally accepted definition of axial lesions in psoriatic arthritis (axPsA), and the diagnostic criteria are extrapolated from the recommendations for ankylosing spondylitis and axial spondyloarthritis.Objective: To evaluate data of magnetic resonance imaging (MRI) of spine and sacroiliac joints (SIJ) in patients with psoriasis complaining of chronic back pain of any cause.Material and methods. 143 patients were enrolled to the study, including 57 (39.9%) men and 86 (60.1%) women, median age – 47 [36; 57] years, mean duration of psoriasis was 17.4±13.4 years. In all patients, the agreement of the existing symptoms with the inflammatory back pain (IBP) criteria of A. Calin et al., M. Rudwaleit et al. and ASAS was checked. All patients underwent MRI of the spine and SIJ, determination of ESR, CRP levels, HLA-B27 and consultations with a dermatologist and a rheumatologist.Results and discussion. An association of bone marrow edema (BME) in the spine and SIJ with nail involvement (odds ratio, OR 2.32; 95% confidence interval, CI 1.12–4.81; p=0.035), palmoplantar psoriasis (OR 3.85; 95% CI 1.43–10.41; p=0.054) and a weak correlation with PASI (r=0.329, p=0.034) was found. There were no statistically significant differences in PASI between patients with BME and without BME. In patients with IBP who fulfilled the criteria of A. Calin et al., osteitis in the SIJ was present in 19 (34.5%; OR 2.79; 95% CI 1.26–6.19; p=0.01); Berlin criteria of 4 signs – 25 (28.7%; OR 2.42; 95% CI 1.00–5.84; p=0.045); Berlin criteria of 3 signs – in 18 (24.0%; OR 1.12; 95% CI 0.51–2.44; p=0.783); ASAS criteria – in 17 (34.0%; OR 2.48; 95% CI 1.12–5.49; p=0.023). In almost half of the patients with BME in the spine or SIJ, the symptoms did not fulfil the criteria for IBP. Signs such as the presence and duration of morning stiffness had a high prognostic value. Isolated spondylitis (presence of BME in vertebrae and absence of BME in SIJ) was rarely found in patients with IBP fulfilling various criteria (in 4.0–8.1% of cases).Conclusion. Considering the existing discrepancy between symptoms and MRI results, it is necessary to develop independent tools for screening and early diagnosis of axPsA.

Whole-joint histogram analysis of different models of diffusion weighted imaging in evaluating disease activity of axial spondyloarthritis.

To assess whole-joint histogram analysis of mono-exponential and bi-exponential diffusion weighted and diffusion kurtosis imaging in evaluating disease activity of axial spondyloarthritis (axSpA). A total of 82 patients with axSpA who underwent both DKI and multi b diffusion weighted imaging of the sacroiliac joints were divided into active and inactive disease groups based on clinical activity indices. Another 17 patients with nonspecific low back pain were included as a control group. The SPARCC scoring system was used to assess the level of sacroiliac joint bone marrow edema. Histogram parameters of apparent diffusion coefficient (ADC), true diffusion coefficient (D), perfusion fraction (f), pseudodiffusion coefficient (D*), mean kurtosis (MK), and mean diffusivity (MD) were calculated. Regions of interest were placed covering the entire sacroiliac joint. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance of imaging parameters in distinguishing different groups. Regression analysis was applied to determine the correlation between imaging parameters and clinical activity indices. All of the histogram parameters distinguished the active from inactive groups with a low area under the curve (AUC) (max AUCs≤0.71), while the SPARCC score failed to differentiate the two groups (p = 0.08). MD, MK, D, D*, and ADC showed good performance in differentiating active and inactive from control groups (max AUC = 0. 81 ~ 0.98). f50 differentiated the active from control groups with an AUC of 0.72, significantly lower than the maximum AUC for MD, MK, D, ADC, and SPARCC score (all p < 0.05). The max AUC of MD in differentiating inactive from control groups was significantly higher than that of D* and the SPARCC score. MD, D, D*, f, and ADC were positively correlated with BASDAI, while MK was negatively correlated with BASDAI. Only MD was positively correlated with hsCRP. Whole-joint histogram analysis of mono-exponential, bi-exponential diffusion weighted, and diffusion kurtosis imaging showed good diagnostic performance in differentiating active and inactive axSpA from patients with non-specific back pain. All the imaging parameters were correlated with BASDAI except for SPARCC score. Only DKI-derived MD was correlated with an increase in hsCRP, suggesting its potential use as an imaging biomarker for disease activity in axSpA. 1. No significant difference was found between the three models of diffusion weighted imaging in evaluating disease activity of axial spondyloarthritis.2. Only DKI-derived MD was correlated with an increase in hsCRP, suggesting its potential use as an imaging biomarker for disease activity in axSpA.

Two-year imaging outcomes from a phase 3 randomized trial of secukinumab in patients with non-radiographic axial spondyloarthritis

BackgroundRadiographic progression and course of inflammation over 2 years in patients with non-radiographic axial spondyloarthritis (nr-axSpA) from the phase 3, randomized, PREVENT study are reported here.MethodsIn the PREVENT study, adult patients fulfilling the Assessment of SpondyloArthritis International Society classification criteria for nr-axSpA with elevated CRP and/or MRI inflammation received secukinumab 150 mg or placebo. All patients received open-label secukinumab from week 52 onward. Sacroiliac (SI) joint and spinal radiographs were scored using the modified New York (mNY) grading (total sacroiliitis score; range, 0–8) and modified Stoke Ankylosing Spondylitis Spine Score (mSASSS; range, 0–72), respectively. SI joint bone marrow edema (BME) was assessed using the Berlin Active Inflammatory Lesions Scoring (0–24) and spinal MRI using the Berlin modification of the AS spine MRI (ASspiMRI) scoring (0–69).ResultsOverall, 78.9% (438/555) of patients completed week 104 of the study. Over 2 years, minimal changes were observed in total radiographic SI joint scores (mean [SD] change, − 0.04 [0.49] and 0.04 [0.36]) and mSASSS scores (0.04 [0.47] and 0.07 [0.36]) in the secukinumab and placebo-secukinumab groups. Most of the patients showed no structural progression (increase ≤ smallest detectable change) in SI joint score (87.7% and 85.6%) and mSASSS score (97.5% and 97.1%) in the secukinumab and placebo-secukinumab groups. Only 3.3% (n = 7) and 2.9% (n = 3) of patients in the secukinumab and placebo-secukinumab groups, respectively, who were mNY-negative at baseline were scored as mNY-positive at week 104. Overall, 1.7% and 3.4% of patients with no syndesmophytes at baseline in the secukinumab and placebo-secukinumab group, respectively, developed ≥ 1 new syndesmophyte over 2 years. Reduction in SI joint BME observed at week 16 with secukinumab (mean [SD], − 1.23 [2.81] vs − 0.37 [1.90] with placebo) was sustained through week 104 (− 1.73 [3.49]). Spinal inflammation on MRI was low at baseline (mean score, 0.82 and 1.07 in the secukinumab and placebo groups, respectively) and remained low (mean score, 0.56 at week 104).ConclusionStructural damage was low at baseline and most patients showed no radiographic progression in SI joints and spine over 2 years in the secukinumab and placebo-secukinumab groups. Secukinumab reduced SI joint inflammation, which was sustained over 2 years.Trial registrationClinicalTrials.gov, NCT02696031.

A Novel Treatment Method for Ankylosing Spondylitis Combined With Sacroiliac Joint Bone Marrow Edema

Objective: To investigate whether high-energy extracorporeal shock wave therapy (ESWT) combined with conventional oral medicine as a potential novel therapeutic approach for the treatment of ankylosing spondylitis (AS)combined with sacroiliac joint bone marrow edema. Materials &amp; Methods: 40 patients were divided into two groups and were treated with or without ESWT in combination with conventional oral medicine. A visual analog scale (VAS) score of spinal pain, as well as indicators of spinal mobility, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) scores, inflammatory index (C-reactive protein, blood cell sedimentation rate), and other indicators were compared between the two groups. The Spondyloarthritis Research Consortium of Canada (SPARCC) scoring system was used to evaluate pain and structural damage in the sacroiliac joint. Results: (1) After one month of treatment (T1), VAS, BASDAI, BASFI, and SPARCC scores were lower in both groups than at the start of treatment (T0) (P &lt; 0.05), with greater decreases observed in the treatment group (P &lt; 0.05). (2) Also, at T1, indicators of spinal mobility for the two groups were improved (P &lt; 0.05). (3) ESR and C-reactive protein levels for the two groups decreased significantly at T1 versus T0 (P &lt; 0.05). Conclusion: ESWT combined with oral medication can significantly relieve pain and improve clinical functional symptoms for patients with AS. It can also reduce sacroiliac joint bone marrow edema and control the inflammatory reaction in the sacroiliac joint, which represents a novel, effective, reliable, and safe clinical treatment therapeutic method. Keywords: Ankylosing spondylitis, Sacroiliac joint, extracorporeal shock wave therapy, oral medicine.

Electronic focusing high-nergy extracorporeal shockwave combined with conventional oral medicine for the treatment of ankylosing spondylitis

To observe the progress of disease activity and sacroiliac joint imaging in patients with ankylosing spondylitis treated by extracorporeal shockwave combined with conventional oral medicine, and find a new safe and effective therapeutic method. The clinical data of 30 patients with ankylosing spondylitis treated from January 2018 to December 2018 were retrospectively analyzed. Including 20 males and 10 females, aged from 18 to 50 years with an average of (34.50±9.60) years. All 30 patients had different degrees of sacroiliac joint bone marrow edema on MRI before treatment. Thirty patients were divided into treatment group and control group according to different treatment methods. Among them, 15 cases in control group were treated with non-steroidal anti-inflammatory drugs and sulfasalazine enteric-coated tablets, for the 15 cases in treatment group, in addition to oral medicine in line with control group, electronic focusing high-energy extracorporeal shockwave therapy was added. The course of disease, age, pre- and post-treatment erythrocyte sedimentation rate, C-reactive protein in the two groups were analyzed; and visual analogue scale (VAS) and spondyloarthritis research consortium Canada (SPARCC) scoring system were used to evaluate the pain of the sacroiliac joint and the structural damage of the sacroiliac joint;Bath ankylosing spondylitis disease activity index (BASDAI) was calculated. All patients were followed up for at least 3 months. One month after treatment, VAS, and SPARCC scores in treatment group were significantly better than in control group (P<0.05). After 1 month of treatment, there was no significant difference in BASDAI, erythrocyte sedimentation rate and C-reactive protein between two groups(P>0.05). VAS, BASDAI, SPARCC, erythrocyte sedimentation rate, and C-reactive protein of all patients after treatment were significantly improved compared with those before treatment (P< 0.01). Electronic focusing high-energy extracorporeal shockwave combined with conventional oral medicine in the treatment of ankylosing spondylitis has a good clinical effect in rapidly relieving pain, improving disease activity, and preventing imaging progress. In addition, it is safe and non-invasive, which is worthy of clinical application.

Dual-energy computed tomography for the detection of sacroiliac joints bone marrow oedema in patients with axial spondyloarthritis.

To investigate the diagnostic performance of dual-energy computed tomography (DECT) in detection bone marrow oedema (BME) in patients with sacroiliitis associated with axial spondyloarthritis (axial SpA). Patients with axial SpA according to the ASAS criteria underwent DECT and 1.5-T magnetic resonance imaging (MRI). DECT was post-processed for generating virtual non-calcium (VNCa) images. The presence of abnormal bone marrow attenuation was scored on DECT VNCa images and MRI using a four-point classification system: 0-1 = absent or non-significant oedema, 2 = oedema present in a third of the articular surface, 3 = oedema present in 2/3 of the articular surface, 4 = diffuse oedema throughout the articular surface. Diagnostic accuracy values for BME were calculated for DECT images (quantitative assessment) by using receiver operating characteristic (ROC) curves analysis, applying MRI as gold standard. Eighty sacroiliac joints from 40 axial SpA patients were included for study analysis, and 36 sacroiliac joints (45%) were classified as having BME at MRI and compared to DECT. Sensitivity, specificity, and positive likelihood ratio (LR+) in the identification of BME at DECT were 90.0%, 92.8%, and 12.6 respectively. Negative LR was 0.11, positive predictive value 93.1%, and negative predictive value 89.7%. The area under the curve (AUC) was 0.953 in the differentiation of the presence of BME. A cut-off value of -1.6 HU (Youden's index = 0.828) yielded a sensitivity of 90.0% and specificity of 92.8%, with an LR+ of 12.6, in the detection of BME in the sacroiliac joints. DECT VNCa images had good diagnostic performance in the evaluation of the extent of BME in patients with sacroiliitis associated with axial SpA.

Which factors are associated with bone marrow oedema suspicious of axial spondyloarthritis as detected by MRI in the sacroiliac joints and the spine in the general population?

ObjectiveIdentify factors associated with presence and extension of spinal and sacroiliac joints (SIJ)–MRI lesions suggestive of axial spondyloarthritis (axSpA) in a population-based cohort (Study of Health in Pomerania) aged <45...

Axial involvement in patients with early peripheral spondyloarthritis: a prospective MRI study of sacroiliac joints and spine

ObjectivesTo assess axial involvement on MRI in early peripheral spondyloarthritis (pSpA) and to evaluate whether axial inflammation predicts relapse on treatment withdrawal.MethodsFifty-six patients with early, active, newly diagnosed pSpA underwent...

OP0106 SECUKINUMAB 150 MG SIGNIFICANTLY IMPROVED SIGNS AND SYMPTOMS OF NON-RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS: 52-WEEK RESULTS FROM THE PHASE III PREVENT STUDY

Background:Axial spondyloarthritis (axSpA) spectrum covers radiographic axSpA and non-radiographic axSpA (nr-axSpA). PREVENT (NCT02696031) is the first phase III, placebo (PBO) controlled study evaluating secukinumab (SEC) 150 mg with (LD) or without loading (NL) dose, in patients (pts) with nr-axSpA.1The study had 2 independent analysis plans as per EU (Wk 16) and US (Wk 52) regulatory requirements.Objectives:To report efficacy through Wk 52 and safety up to two years for the PREVENT study.Methods:555 pts fulfilling ASAS criteria for axSpA plus abnormal CRP and/or MRI, without evidence of radiographic changes in sacroiliac (SI) joints according to modified New York Criteria for AS were enrolled. All images were assessed centrally before inclusion. Pts were randomised (1:1:1) to SEC 150 mg with LD, NL, or PBO at baseline (BL). LD pts received SEC 150 mg at Wks 1, 2, 3, and 4, and then every 4 wks (q4wk) starting at Wk 4. NL pts received SEC 150 mg at BL and PBO at Wks 1, 2, and 3, and then 150 mg q4wk. Switch to open-label (OL) SEC 150 mg or standard of care (SoC) was permitted after Wk 20. Primary endpoint was ASAS40 at Wk 16 (LD) and at Wk 52 (NL) in anti-TNF-naïve pts. Secondary endpoints (overall population) included ASAS40, BASDAI50, SI joint bone marrow edema (BME) score by MRI at Wks 16 and 52 and ASDAS-CRP inactive disease (ID) at Wk 52. Endpoints were analysed according to statistical hierarchy. Analysis used non responder imputation through Wk 52. Safety analyses included all pts who received ≥1 dose of study treatment.Results:Overall, 481 pts completed 52 wks with no major differences in retention across groups: 84.3% (156/185; LD), 89.7% (165/184; NL) and 86.0% (160/186; PBO). BL characteristics were similar across groups; 90% pts were anti-TNF-naïve, 56-58% pts had elevated CRP, 71-75% pts had evidence of SI joint inflammation by MRI. Proportion of pts who switched to OL or SoC between Wks 20 and 48 was 52.1% (LD), 49.2% (NL), and 67.4% (PBO). Primary endpoints at Wk 16 and Wk 52 were met (Table). SEC 150 mg LD or NL significantly improved secondary endpoints at Wk 16 and 52 vs PBO (Table). SEC significantly reduced SI joint MRI BME score vs PBO at Wk 16 (-1.68 and -1.03 vs -0.39;P= 0.0197 and 0.026, LD and NL respectively). No unexpected safety signals were reported.Conclusion:SEC 150 mg provided significant and sustained improvement in signs and symptoms of pts with nr-axSpA through Wk 52. MRI BME scores were reduced accordingly. There was no major difference between LD and NL. Safety of SEC was consistent with previous reports.2

Frequency of MRI changes suggestive of axial spondyloarthritis in the axial skeleton in a large population-based cohort of individuals aged

ObjectiveTo investigate the frequency of bone marrow oedema (BME) and fatty lesions (FL) suggestive of axial spondyloarthritis (axSpA) on MRI of the spine and sacroiliac joints (SIJ) in a general...

A quick decrease of bone marrow edema in sacroiliac joint could be served as a novel marker for dose tapering of etanercept in ankylosing spondylitis patients.

The purpose of this study was to investigate the correlation of bone marrow edema (BME) in sacroiliac joint (SIJ) with clinical characteristics and clinical response, and whether the quick decrease of BME could be served as a novel marker for dose tapering of etanercept in ankylosing spondylitis (AS) patients.Ninety active AS patients underwent etanercept treatment for 6 months were enrolled consecutively and classified into standard dose group (n = 37) and dose tapering group (n = 53). BME in SIJ and clinical response were assessed by SPARCC criteria and ASAS 40 response criteria, respectively. “Quick decrease of BME in SIJ” was defined as the decrease of SPARCC score≥50% from M0 to M1.BME in SIJ was positively correlated with pain VAS score, BASDAI score, CRP, IL-1β, IL-17, and TNF-α levels. ASAS 40 response rate at M6 was lower in dose tapering group than standard dose group, while higher in patients with a quick decrease of BME in SIJ than other patients. Besides, the ASAS 40 response rate in dose tapering group was similar to standard dose group in patients with a quick decrease of BME in SIJ but was lower than standard dose group in patients without a quick decrease of BME in SIJ at M6.A quick decrease of BME in SIJ predicts better treatment response to etanercept, and it might be served as a novel marker for dose tapering initiation of etanercept in AS patients.

Association Between Inflammatory Back Pain Characteristics and Magnetic Resonance Imaging Findings in the Spine and Sacroiliac Joints

To investigate the association between magnetic resonance imaging (MRI) findings at the sacroiliac (SI) joints and vertebral endplates and pain characteristics assumed to be indicative of axial inflammation. Patients ages 18-40 years with persistent low back pain referred to an outpatient spine clinic participated, including an unknown proportion of axial spondyloarthritis patients. Data included MRI of the spine and SI joints and self-reported responses to questions covering the Calin, Berlin, Assessment of Spondyloarthritis International Society, and Bailly inflammatory back pain (IBP) definitions. In the 1,020 included patients, 53% were women, and the median age was 33 years. Positive associations were found between the SI joint MRI findings and pain characteristics, odds ratios ranging from 1.4 to 2.7. SI joint bone marrow edema (BME) was associated with morning stiffness >60 minutes, and SI joint erosions with the Calin, Berlin, and Bailly IBP definitions, alternating buttock pain, and good response to nonsteroidal antiinflammatory drugs. SI joint fatty marrow deposition (FMD) was associated with insidious onset, and SI joint sclerosis with pain at night. In addition, the spinal MRI changes were associated with IBP, odds ratios ranging from 1.4 to 2.0; vertebral endplate BME was associated with morning stiffness, and vertebral endplate FMD with the Calin and Bailly IBP definitions, improvement with exercise, morning stiffness >30 minutes, and pain worst in the morning. The identified associations between inflammatory MRI findings and pain characteristics indicate that axial inflammation to some degree induces a specific pain pattern. Thus, the results add to knowledge of axial inflammatory processes. However, all identified associations were weak, which compromises the use of IBP as a marker of axial inflammation.

Development and Validation of MRI Sacroiliac Joint Scoring Methods for the Semiaxial Scan Plane Corresponding to the Berlin and SPARCC MRI Scoring Methods, and of a New Global MRI Sacroiliac Joint Method.

To develop semiaxial magnetic resonance imaging (MRI) scoring methods for assessment of sacroiliac joint (SIJ) bone marrow edema (BME) in patients with axial spondyloarthritis, and to compare the reliability with equivalent semicoronal scoring methods. Two semiaxial SIJ MRI scoring methods were developed based on the principles of the semicoronal Berlin and Spondyloarthritis Research Consortium of Canada (SPARCC) methods. A global quadrant-based method was also developed. Baseline and 12-week MRI of the SIJ from 51 patients participating in a randomized double-blind placebo-controlled trial of adalimumab 40 mg every other week versus placebo were scored by the semiaxial and the corresponding semicoronal methods. Results were compared by linear regression analysis. The reproducibility and sensitivity were evaluated by intraclass correlation coefficients (ICC) and smallest detectable change [SDC, absolute values and percentage of the highest observed score (SDC-HOS)]. Interreader and intrareader ICC were moderate to very high for semiaxial scoring methods (baseline 0.83-0.88 and 0.85-0.97; change 0.33-0.78), while high to very high for semicoronal scoring methods (baseline 0.90-0.92 and 0.93-0.97; change 0.77-0.89). Association between semiaxial and semicoronal scores were high for both the Berlin and SPARCC method (baseline: R2 = 0.93 and 0.88; change: R2 = 0.82 and 0.87, respectively), while lower for the global method (baseline: R2 = 0.79; change: R2 = 0.54). The SDC-HOS were 9.8-18.6% and 5.9-10.7% for the semiaxial and semicoronal methods, respectively. Detection of SIJ BME in the semiaxial scan plane is feasible and reproducible. However, a slightly lower reliability of all 3 semiaxial methods supports the general practice of using the coronal scan-plane in therapeutic studies.

Osteitis condensans ilii may demonstrate bone marrow edema on sacroiliac joint magnetic resonance imaging.

To reveal whether bone marrow edema (BME) may appear with osteitis condensans ilii (OCI) on sacroiliac joint (SIJ) magnetic resonance imaging (MRI) and to evaluate the characteristics of BME demonstrated with OCI. Altogether 27 symptomatic female OCI patients with both complete clinical records and SIJ-MRI examination data were enrolled for retrospective analysis. SIJ-MRI exams were retrospectively analyzed by two musculoskeletal radiologists. Patients were separated into BME group and non-BME group according to whether there was BME of SIJ demonstrated as high signal intensity on MR short tau inversion recovery sequences beneath the SIJ articular surface. For the BME group the characteristics of BME including distribution pattern and location, depth and signal intensity were assessed. BME could be seen in 48.1% (13/27) OCI patients. Ilium side BME demonstrated with OCI was centered at the ventral-cartilaginous joint part and had a trend of extending to bone marrow beneath the arcuate line in a continuous distribution pattern. There was a trend that OCI patients with BME demonstrated on MRI were younger (P = 0.054, Student's t-test) and with shorter pain duration (P = 0.091, Student's t-test) than OCI patients without BME, but the differences did not reaching statistical significance. More cases endured diagnosis delay in the BME group than the non-BME group (nine cases vs. two cases, P = 0.006, Fisher's exact test). Some OCI may demonstrate BME on SIJ-MRI. Careful observation of the location and distribution pattern of BME may give some help in differentiating OCI from early spondyloarthritis.

Axial spondyloarthritis classification criteria: the debate continues.

The Assessment of Spondyloarthritis International Society (ASAS) axial spondyloarthritis (axSpA) classification criteria marked a major step forward in SpA research, distinguishing axial from peripheral disease, and allowing earlier identification through MRI. This facilitated all aspects of research including epidemiology, therapeutics and patient outcomes. The ASAS axSpA classification criteria have been applied broadly in research, and were validated in a recent meta-analysis of international studies. Concerns arose because of clinical differences between the clinical and imaging arms, which imply different risk for radiographic progression, and perform differently in validation studies. Low specificity of the MRI finding of sacroiliac joint bone marrow edema may lead to misclassification in populations with low axSpA prevalence. We suggest methodology to improve upon the criteria, including rigorous assessment of potential candidate criteria sets, discrete choice experiments to allow consideration of feature weights, and validation. Separately, assessment of structural and inflammatory MRI abnormalities should be performed to refine the MRI definition of sacroiliitis. The debate regarding the validation and modification of the ASAS axSpA classification criteria should lead to international efforts to build upon the gains made by these criteria, to further refine the axSpA population definitions for research and ultimately improve patient outcomes.

Prevalence of degenerative and spondyloarthritis-related magnetic resonance imaging findings in the spine and sacroiliac joints in patients with persistent low back pain.

To estimate the prevalence of degenerative and spondyloarthritis (SpA)-related magnetic resonance imaging (MRI) findings in the spine and sacroiliac joints (SIJs) and analyse their association with gender and age in persistent low back pain (LBP) patients. Degenerative and SpA-related MRI findings in the whole spine and SIJs were evaluated in Spine Centre patients aged 18-40 years with LBP. Among the 1,037 patients, the prevalence of disc degeneration, disc contour changes and vertebral endplate signal (Modic) changes were 87 % (±SEM 1.1), 82 % (±1.2) and 48 % (±1.6). All degenerative spinal findings were most frequent in men and patients aged 30-40 years. Spinal SpA-related MRI findings were rare. In the SIJs, 28 % (±1.4) had at least one MRI finding, with bone marrow oedema being the most common (21 % (±1.3)). SIJ erosions were most prevalent in patients aged 18-29 years and bone marrow oedema in patients aged 30-40 years. SIJ sclerosis and fatty marrow deposition were most common in women. SIJ bone marrow oedema, sclerosis and erosions were most frequent in women indicating pregnancy-related LBP. The high prevalence of SIJ MRI findings associated with age, gender, and pregnancy-related LBP need further investigation of their clinical importance in LBP patients. • The location of vertebral endplate signal changes supports a mechanical aetiology. • Several sacroiliac joint findings were associated with female gender and pregnancy-related back pain. • Sacroiliac joint bone marrow oedema was frequent and age-associated, indicating a possible degenerative aetiology. • More knowledge of the clinical importance of sacroiliac joint MRI findings is needed.