non-SpA Patients Research Articles

Association of anatomical variants of the sacroiliac joint with bone marrow edema in patients with axial spondyloarthritis.

To determine the prevalence of sacroiliac joint variants in patients with axial spondyloarthritis (axSpA) using MRI-based synthetic CT images and to evaluate their relationships with the presence of bone marrow edema, as this may potentially complicate diagnosing active sacroiliitis on MRI in patients with suspected axSpA. 172 patients were retrospectively included. All patients underwent MRI because of clinical suspicion of sacroiliitis. The diagnosis of axSpA was made by a tertiary hospital rheumatologist. Two readers independently determined the presence of bone marrow edema and the presence of one or more of the nine known sacroiliac joint (SIJ) variants. SIJ variants were common in axSpA patients (82.9%) and the non-SpA group (85.4%); there were no significant differences in prevalence. Bone marrow edema was frequently found in axSpA (86.8%) and non-SpA patients (34%). AxSpA patients with SIJ variants (except for accessory joint) demonstrated 4 to 10 times higher odds for bone marrow edema, however not statistically significant. The more variants were present in this group, the higher the chance of bone marrow edema. However, some multicollinearity cannot be excluded, since bone marrow edema is very frequent in the axSpA group by definition. SIJ variants are common in axSpA and non-SpA patients. SIJ variants were associated with higher prevalence of bone marrow edema in axSpA patients, potentially due to altered biomechanics, except for accessory joint which may act as a stabilizer.

Proton density fat fraction (PDFF) maps aid fat metaplasia evaluation in the sacroiliac joints in additional to T1WI: Improved diagnostic accuracy in axial spondyloarthritis

PurposeTo evaluate the added value of qualitative and quantitative fat metaplasia analysis using proton-density fat fraction (PDFF) map in additional to T1-weighted imaging (T1WI) of the sacroiliac joints (SIJ) for diagnosis of axial spondyloarthritis (axSpA). MethodPatients aged 18–45 years with axSpA were enrolled. Non-SpA patients and healthy volunteers were included as controls. All participants underwent 3.0T MRI of the SIJs including semi-coronal T1WI and semi-coronal chemical-shift encoded MRI sequence for generating PDFF map. Each joint was divided into four quadrants for analysis. Two independent readers scored fat metaplasia on T1WI alone or with additional PDFF map and measured PDFF values in different reading sessions. Using clinical diagnosis as the reference, diagnostic accuracy of visual scores and PDFF measurements was evaluated by area under the receiver operating characteristic curve (AUC). Inter-reader agreement was evaluated by the intra-class correlation coefficient (ICC). ResultsForty-nine patients with axSpA and thirty-six controls were included. Qualitative fat metaplasia scores using additional PDFF map performed better than using T1WI alone (AUC: Reader 1, 0.847 vs 0.795, p = 0.082; Reader 2, 0.785 vs 0.719, p = 0.048). AUCs of quantitative analysis using number of quadrants with PDFF value ≥75 % were higher than qualitative analysis using T1WI alone (Reader 1, 0.863 vs 0.795, p = 0.046; Reader 2, 0.823 vs 0.785, p = 0.011). ICCs were 0.854 to 0.922 for qualitative analysis and 0.935 for quantitative analysis. ConclusionsAdditional PDFF map can increase the diagnostic accuracy for axSpA by qualitative and quantitative fat metaplasia analysis, in comparison to using T1WI alone.

Use of Imaging in Axial Spondyloarthritis for Diagnosis and Assessment of Disease Remission in the Year 2022.

Medical imaging remains the cornerstone of diagnostics and follow-up of axial spondyloarthritis (axSpA) patients. With the lack of specific biomarkers allowing monitoring of disease activity and progression, clinicians refer to imaging modalities for accurate evaluation of the axSpA burden. Technological advances and increasing availability of modern imaging techniques such as MRI have enabled faster diagnosis of the disease, hence dramatically changed the diagnostic delay and improved the prognosis and functional outcomes for axSpA patients.Active sacroiliitis as visualized by MRI has been widely accepted as a diagnostic tool, and definitions of inflammatory and structural lesions within the axial skeleton have been developed. Recently, it has been acknowledged that bone marrow edema, suggestive of sacroiliitis, is a common finding among non-SpA patients, and could be attributed to mechanical loading or accumulate with age in healthy individuals. Therefore, it is crucial to distinguish between true pathological and concealing imaging findings, not only for diagnostic but also for disease remission purposes. New imaging modalities, aimed for in vivo visualization of specific molecular processes, could be employed to cross-validate findings from techniques used in daily clinical practice. This review critically evaluates the use of different imaging modalities for diagnosis and assessment of disease remission in axSpA in the year 2022.

The influence of age on the prevalence of inflammatory and structural MRI lesions in the sacroiliac joints of patients with and without axial spondyloarthritis.

To compare the influence of age on inflammatory (bone marrow oedema [BME]) and structural (fat lesions [FL], erosions and ankylosis) MRI lesions in the sacroiliac joints (SIJ) of patients with and without axial spondyloarthritis (axSpA). In a retrospective study, SIJ MRI (STIR/T1 sequences) of consecutive patients with chronic back pain diagnosed with axSpA or non-SpA were evaluated based on SIJ quadrants (SIJ-Q). Two blinded readers evaluated BME and structural lesions. Reader agreement was evaluated for prevalence of MRI lesions related to age. MRIs of 309 (175 axSpA, 134 non-SpA) patients were evaluated. Their mean age was 38.5 (11.4) and 43.4 (13.8) years, 67% and 36% were male, CRP was 1.6 (2.4) and 1.1 (2.1) mg/dl and median symptom duration was 48 and 60 months for axSpA and non-SpA, respectively. SIJ-Q with BME and erosions were significantly more frequent in axSpA vs non-SpA patients independent of age, while this difference was seen for FL only in patients ≥50 years. The proportion of patients with ≥1 or ≥3 BME or chronic lesions except for FL increased with age in both groups, and was constantly higher in axSpA vs non-SpA. In univariate analyses, only female sex was significantly associated with more FL. The proportion of patients with MRI lesions was high in both axSpA and non-SpA patients. However, the prevalence of BME and erosions was significantly more frequent in patients with axSpA, was independent of age and also allowed for discrimination. FL occurred more frequently only in older age groups and were less reliable for discrimination vs non-SpA patients.

Quantification of Fat Metaplasia in the Sacroiliac Joints of Patients With Axial Spondyloarthritis by Chemical Shift-Encoded MRI: A Diagnostic Trial.

ObjectiveTo study the diagnostic performance of chemical shift-encoded MRI (CSE-MRI) in the diagnosis of axial spondyloarthritis (axSpA).MethodsCSE-MRI images were acquired for consecutive patients complaining of back pain as well as healthy volunteers. Proton density fat fraction (PDFF) values were measured independently by two readers. Diagnostic performance of CSE-MRI was analyzed by sensitivity analysis and ROC curve analysis. Logistic regression analysis was employed to investigate the risk factors of extensive fat deposition in the SIJs.ResultsA total of 52 r-axSpA patients, 37 nr-axSpA patients, 24 non-SpA patients and 34 healthy volunteers were included. Mean PDFF values in the SIJs of patients with r-axSpA and nr-axSpA (72.7% and 64.5%) were significantly higher than non-SpA patients and healthy volunteers (56.0% and 57.6%) (p<0.001). By defining extensive fat deposition in the SIJs as ≥8 ROIs with PDFF values over 70%, its sensitivity and specificity in diagnosing axSpA reached 72.47% and 86.21%%. By joining bone marrow edema (BME) with ≥8 ROIs (PDFF>70%), 22 (24.71%) and 23 (25.84%) more axSpA patients were classified as SIJ MRI (+) by reader 1 and 2, but specificities decreased by 15.52% and 10.34%. Multivariate logistic regression analysis confirmed longer disease duration as the independent risk factor of extensive fat deposition in SIJs (OR=1.15, 95%CI[1.03, 1.32]), while bDMARDs medication was a protective factor (OR=0.15, 95%CI[0.04, 0.51]).ConclusionCSE-MRI is a reliable tool to quantitively assess the fat metaplasia in the SIJs of axSpA patients. Extensive fat deposition in the SIJs could add incremental diagnostic value to BME, but at the cost of decreased specificities.

Frequency and anatomic distribution of magnetic resonance imaging lesions in the sacroiliac joints of spondyloarthritis and non-spondyloarthritis patients.

Background:Lesions detected by magnetic resonance imaging (MRI) of the sacroiliac joints are critical to the diagnosis of non-radiographic axial spondyloarthritis. However, inflammatory and structural lesions may be encountered in other conditions.Objectives:The objective of this study was to evaluate and compare the frequency and localization of inflammatory and structural lesions on MRIs of the sacroiliac joint of spondyloarthritis (SpA) and non-spondyloarthritis (non-SpA) patients.Design:This is a retrospective study including 200 patients, each having undergone an MRI of the sacroiliac joints.Methods:Two experienced readers evaluated the whole set of images to detect erosions, subchondral sclerosis, fatty lesions, bone marrow edema (BME) and ankylosis according to the definitions established by the ASAS MRI working group. We divided sacroiliac joints into five segments: upper, antero-middle, intermediate-middle, postero-middle and lower.Results:A total of 96 subjects with SpA (mean age 37.4 ± 11.8 years) and 104 without SpA (mean age 39.9 ± 11.6 years) were included. Of the 96 SpA patients, 65% had inflammatory buttock pain compared with 25% in the non-SpA group. BME was seen in 65% of SpA patients, mainly in the intermediate-middle segment, and in 20% of non-SpA patients, predominantly in the antero-middle segment. Subchondral sclerosis occurred in 44% of non-SpA patients, mostly in the antero-middle segment, and in 36% of SpA patients. Fatty lesions were present in 34% of SpA and in 21% of non-SpA patients. Erosions were seen in 25% of non-SpA and in 60% of SpA patients. BME and structural lesions were minimally observed in the postero-middle segment in non-SpA patients.Conclusion:Inflammatory and structural lesions were observed in all segments of the joint in SpA, mainly in the middle segments, while lesions predominantly affected the antero-middle segment in non-SpA, and were uncommon in the postero-middle segment.

Frequency of pertinent MRI abnormalities of the sacroiliac joints of patients without spondyloarthropathies: a systematic review of the literature.

MRI criteria are central to the diagnosis of non-radiographic axial spondyloarthropathy (nr-axSpA). The cardinal feature of nr-axSpa is inflammatory low back pain, which may be difficult to distinguish from highly prevalent non-specific low back pain. This study aims to determine the frequency of relevant MRI findings in the sacroiliac joints (SIJ) of patients without Spondyloarthropathy (SpA), and therefore estimate the specificity of MRI scans for SpA. EMBASE and Medline were searched and limited to English. Titles were screened for relevance, with studies that included primary MRI findings in patients without SpA triggering retrieval. Retrieved papers were reviewed, data extracted by two authors and quality criteria (QUADAS 2) were applied. Findings were considered for asymptomatic and symptomatic individuals. The search recovered 2172 articles. Abstracts of 117 were reviewed for full text retrieval, 11 papers met eligibility criteria. These papers described MRI findings of 1180 asymptomatic patients and 1318 with low back symptoms but without SpA. In relevant populations, bone marrow oedema was found in 22% (95% CI 19-25) of asymptomatic and 20% (95% CI 18-22) of asymptomatic individuals. In all non-Spa patients, sclerosis was found in 13.4% and erosions in 6.5%. There is a significant frequency of diagnostically pertinent MRI abnormalities in the SIJ of patients without SpA. These are present in both asymptomatic and symptomatic individuals. Findings, such as oedema and sclerosis, lack specificity and should be interpreted with caution. Erosions are less frequent and are likely more specific for SpA.

Influence of pregnancy/childbirth on long-term bone marrow edema and subchondral sclerosis of sacroiliac joints

ObjectiveTo investigate long-term effects of pregnancy/childbirth on bone marrow edema (BME) and subchondral sclerosis of sacroiliac joints (SIJ) in comparison to MRI changes caused by spondyloarthritis (SpA) and assess the influence of birth method and number of children on SIJ-MRI changes.Materials and methodsThis is a retrospective cohort study with 349 women (mean age 47 ± 14 years) suffering low back pain. Four subgroups were formed based on SpA diagnosis and childbirth (CB) history. Two musculoskeletal radiologists scored the presence of BME and sclerosis on SIJ-MRI using the Berlin method. Further, an 11-point “global assessment score” representing the overall confidence of SpA diagnosis based on MRI was evaluated in addition to the ASAS (Assessment of Spondyloarthritis International Society) criterion of “positive MRI” for sacroiliitis.ResultsCB did not correlate with BME score (p = 0.38), whereas SpA diagnosis was associated with a higher BME score (r = 0.31, p < 0.001). Both CB (r = 0.21, p < 0.001) and SpA diagnosis (r = 0.33, p < 0.001) were correlated with a higher sclerosis score. CB was not associated with a higher confidence level in diagnosing SpA based on MRI (p = 0.07), whereas SpA diagnosis was associated with a higher score (r = 0.61, p < 0.001). Both CB (phi = 0.13, p = 0.02) and SpA diagnosis (phi = 0.23, p < 0.001) were significantly associated with a positive ASAS criterion for sacroiliitis. In non-SpA patients with CB, number of children (p = 0.001) was an independent predictor of sclerosis score, while birth method yielded no significant effect (p = 0.75).ConclusionPregnancy/CB has no impact on long-term BME on SIJ, however, may cause long-term subchondral sclerosis—similar to SpA-associated sclerosis. Number of children is positively correlated with SIJ sclerosis. Birth method yields no effect on SIJ sclerosis.

P194 Risk factors of axial spondyloarthritis among inflammatory bowel disease patients

Abstract Background Spondyloarthritis (SpA) is the most common extraintestinal manifestation (EIM) in inflammatory bowel disease (IBD) patients. However, the delay for the diagnosis of SpA in IBD patients is still unacceptably long, and may be the main cause of impairment due to ankylosing spondylitis. The aim of this study was to identify predictors of axial SpA in IBD patients, in order to prevent complications. Methods We conducted a retrospective study between 2001 and 2018 including all IBD patients diagnosed with symptomatic axial Spondyloarthritis (SpA) (Group1) and non-SpA patients among IBD (Group2). Diagnosis of SpA was based on ASAS 2009 criteria and confirmed by rheumatologists. Medical data were collected then uni and multivariate statistical analysis (p significant if ≤0.05) were performed. Results Seventy-eight patients with mean age 38 ± 11 years and sex ratio H/F = 1.6 were included. There were 58 (74.4%) Crohn’s disease (CD) patients and twenty patients (25.6%) had ulcerative colitis (UC). The average duration of IBD in all patients was 89.7 ± 69.1 months. SpA group included 26 patients (33.3%), six of whom (23%) had a late-stage disease (ankylosis). Most of the SpA patients (53.8%) had their disease before IBD onset with an average delay of 52.5 ± 68 months between SpA diagnosis and IBD symptoms. In univariate analysis, factors associated with SpA in IBD patients were familial history of IBD (p = 0.025) and the type of IBD (39.7% in CD vs. 15% in UC; p = 0.04). Among CD patients’, structuring-type was significantly associated with SpA (p = 0.04). Multivariate analysis showed that familial history of IBD (OR = 0.17; IC95%; 0.03–0.93; p = 0.04) and CD (OR = 3.72; IC 95%; 0.98–14.15; p = 0.05) were independent risk factors of axial SpA during IBD. EIMs other than SpA were more frequent in group 1 than in group 2 such as peripheral arthropathies (19.2% vs. 8.3% respectively; p = 0.02), anterior uveitis (11.5% vs. 0% respectively; p = 0.01) and erythema nodosum (7.7% vs. 0% respectively; p = 0.04). Conclusion In conclusion, predictors of symptomatic axial SpA were familial history of IBD and CD with structuring behaviour. Early-stage diagnosis is important to avoid ankylosis, which is a major cause of handicap in younger patients.

Are we treating women patients with real axial spondyloarthritis?

IntroductionDuring the last years, regulatory agencies raised some relevant concerns with regard to the possibility of administrating biological therapy (BT) to non-SpA patients. Especially, the possibility of treating women with fibromyalgia as non-radiographic axSpA (nr-axSpA) was mentioned. ObjectivesTo evaluate if the gender distribution and clinical pattern of patients with axSpA initiating biological therapy (BT) was modified in clinical practice after its approval for non radiographic-axSpA (nr-axSpA). MethodsBaseline dataset from a prospective ongoing cohort including all patients with axSpA treated with BT at the Rheumatology Department of University Hospital La Paz, Madrid, Spain, was analysed. Patient's characteristics and disease activity parameters were collected. Based on the approval indication date of BT for nr-axSpA, patients were classified in two periods according to the starting date for the first BT: period 1 (before 2013) and period 2 (during or after 2013). Gender distribution and disease’ characteristics were compared between both groups using Chi-square and Student-t tests. ResultsIn total, 385 patients initiated BT: 266 (69%) in period 1 and 119 (31%) in period 2. No significant differences between both periods were observed regarding gender distribution (38% and 39% of women; p = 0.8). Out of those patients with nr-axSpA initiating BT in period 2, the majority (60%) were men. Women starting BT in period 2 had significantly higher systemic inflammation and mobility restriction compared with women in period 1 [median (interquartile range) CRP 10.2 mg/l (3.0–24.9) vs 3.2 mg/l (2.0–9.4); p = 0.02 and BASMI 2.7 (1.8–3.5) vs. 2.0 (1.2–2.6); p = 0.01, respectively]. In addition, they also presented significantly higher disease activity [BASDAI 6.5 (5.4–8.0) vs. 5.8 (4.6–6.8); p = 0.02; ASDAS, mean (SD) 3.6 ± 3.4 vs. 3.2 ± 1.0; p = 0.02, respectively] and more functional limitation [BASFI 5.7 (3.8–6.7) vs. 4.3 (2.0–6.1); p = 0.01, respectively] than men treated in period 2. ConclusionsIn our clinical practice, the frequency of women who started BT did not increase since their approval for nr-axSpA. Women treated with BT after 2012 had more objective disease activity parameters than before their approval for nr-axSpA treatment.

A referable clinical pattern of spondyloarthritis-associated uveitis

Objective. The aim of the study was to identify a clinical pattern of spondyloarthritis (SpA)-associated uveitis in order to facilitate proper rheumatologic referral by ophthalmologists. Methods. Demographic data were recorded and acute phase reactants were measured using standard methods between May and August 2017, for all adult patients (age > 18 years) presenting with acute uveitis (standardization of uveitis nomenclature). Afterwards, they were referred to a rheumatology clinic to be screened for the 2009 Assessment of SpondyloArthritis International Society (ASAS) classification criteria of SpA. SpA and non-SpA patients were then compared using appropriate statistical tests (significant if p < 0.05). All the patients offered a written informed consent and the study was approved by the local ethics committee. Results. The sample included 67 subjects, of whom 32 (47.8%) were classified with SpA, of whom 21 were known with this diagnosis (median disease duration of 13.6 years), while 11 (34.4% of the SpA subgroup) fulfilled the ASAS classification criteria for SpA without a prior diagnosis. Compared to non-SpA patients, SpA patients were more frequently male urban dwellers, they were significantly younger, they had a higher prevalence of HLA-B27 and recurrent uveitis, and they had higher median of C-reactive protein and lower median of white blood counts. Conclusions. Uveitis is an important revelatory manifestation of SpA. Young men presenting in an ophthalmology department with acute anterior uveitis and inflammatory back pain should be referred to a rheumatology unit. Abbreviations: AAU = Acute Anterior Uveitis, AS = Ankylosing Spondylitis, ASAS = Assessment Of Spondyloarthritis International Society, CRP = C-Reactive Protein, ESR = Erythrocyte Sedimentation Rate, HLA = Human Leukocyte Antigen, IBP = Inflammatory Back Pain, IBD = Inflammatory Bowel Disease, IL = Interleukin, MRI = Magnetic Resonance Imaging, Nsaids = Non-Steroidal Anti-Inflammatory Drugs, SD = Standard Deviation, Spa = Spondyloarthritis, Tnfα = Tumour Necrosis Factor Alpha, WBC = White Blood Count.

Childhood sexual and physical abuse: age at exposure modulates impact on functional outcome in early psychosis patients.

Evidence suggests a relationship between exposure to trauma during childhood and functional impairments in psychotic patients. However, the impact of age at the time of exposure has been understudied in early psychosis (EP) patients. Two hundred and twenty-five patients aged 18-35 years were assessed at baseline and after 2, 6, 18, 24, 30 and 36 months of treatment. Patients exposed to sexual and/or physical abuse (SPA) were classified according to age at the time of first exposure (Early SPA: before age 11 years; Late SPA: between ages 12 and 15 years) and then compared to patients who were not exposed to such trauma (Non-SPA). The functional level in the premorbid phase was measured with the Premorbid Adjustment Scale (PAS) and with the Global Assessment of Functioning (GAF) scale and the Social and Occupational Functioning Assessment Scale (SOFAS) during follow-up. There were 24.8% of patients with a documented history of SPA. Late SPA patients were more likely to be female (p = 0.010). Comparison with non-SPA patients revealed that: (1) both Early and Late SPA groups showed poorer premorbid social functioning during early adolescence, and (2) while patients with Early SPA had poorer functional level at follow-up with lower GAF (p = 0.025) and lower SOFAS (p = 0.048) scores, Late SPA patients did not. Our results suggest a link between exposure to SPA and the later impairment of social functioning before the onset of the disease. EP patients exposed to SPA before age 12 may present long-lasting functional impairment, while patients exposed at a later age may improve in this regard and have a better functional outcome.

FRI0283 Progression of early arthritis to spondyloarthritis after a 10-year follow-up

BackgroundEarly arthritis is often undifferentiated and may resolve spontaneously, remain undifferentiated, or progress to rheumatoid arthritis or to another chronic joint disease such as SpA. There is a need for...

SAT0258 A Prospective Evaluation of the Diagnostic Value of Conventional Radiography, Ultrasound and MRI in Comparison to Clinical Examination for the Assessment of Heel and Knee Enthesitis in Patients With Spondyloarthritis and Controls

BackgroundSpondyloarthritides (SpA) are characterized by inflammatory and structural changes in the axial skeleton and in peripheral joints and entheses. Imaging has an essential role in the new classification criteria for...

SAT0259 ASAS Classification Criteria for Axial Spa Were Superior to ESSG and Amor Criteria in Distinguishing Spa Patients Among Patients with Chronic Back Pain: Results of a Two-Year Follow-Up Study From China

BackgroundIn 2009 the Assessment of SpondyloArthritis international Society (ASAS) developed the new classification criteria for axial spondyloarthritis in a large cohort of patients with recent-onset low back pain.ObjectivesTo evaluated the...

High prevalence of anti-CD74 antibodies specific for the HLA class II-associated invariant chain peptide (CLIP) in patients with axial spondyloarthritis

ObjectivesThe pathogenesis of axial spondyloarthritis (axSpA) is still unclear. There is a strong association with HLA-B27 and other genes. Recently, anti-CD74 antibodies with specificity to a class II-associated invariant chain...

Power Doppler ultrasonography of painful Achilles tendons and entheses in patients with and without spondyloarthropathy—a comparison with clinical examination and contrast-enhanced MRI

The objective of this study was to describe ultrasonography (US) and magnetic resonance imaging (MRI) findings at painful Achilles tendons and entheses in patients with and without spondyloarthropathy (SpA and non-SpA) and healthy control persons (CTRLs). Particularly, we aimed to investigate if any changes differentiate SpA from non-SpA. Finally, we investigated the reliability of US compared to clinical examination of Achilles tendinopathy, using MRI as gold standard reference. Twelve SpA patients and 15 non-SpA patients with pain and tenderness at at least one Achilles tendon and/or enthesis due to sports-related causes and 10 CTRLs were examined at the Achilles tendons and entheses with US, MRI and clinical assessment. Intratendinous changes, entheseal changes, bursitis and peritendonitis were assessed. An US interobserver substudy was performed in nine persons. US findings showed high agreement between observers (median 89 %, κ = 0.64) and with MRI (median 89 %, κ = 0.74). All inflammatory intratendinous changes were less frequent in SpA than non-SpA patients (p < 0.05). Entheseal changes and bursitis were found equally frequent in both patient groups except for enthesophytes, which were most common in the SpA group (p < 0.01). No findings were exclusively found in SpA. When MRI was considered gold standard, US showed higher sensitivity for intratendinous and entheseal changes than clinical examination (median sensitivity 0.83 versus 0.66). Especially, entheseal changes had higher sensitivity than clinical examination without loss of specificity. In conclusion, US performed by a trained operator can be a useful adjunct to clinical examination for improved assessment of Achilles tendons and entheses.

Studying patients with inflammatory back pain and arthritis of the lower limbs clinically and by magnetic resonance imaging: many, but not all patients with sacroiliitis have spondyloarthropathy.

Clinical and magnetic resonance imaging (MRI) data of 170 consecutive patients with inflammatory back pain (IBP) and/or oligoarthritis of the lower limbs were evaluated in a retrospective study. The aim was to determine the frequency of sacroiliitis and spondyloarthropathy (SpA) in this population, and to assess the significance of HLA B27 measurements for diagnosis in early disease. Pelvic X-rays were performed in all IBP patients and dynamic MRI of the sacroiliac joints in patients with IBP who had indefinite results on sacroiliac X-rays (n = 32). European Spondyloarthropathy Study Group criteria for SpA were fulfilled by 106/170 patients (62.4%); eight additional patients had symptoms suggestive of SpA (4.7%). The most frequent SpA subset was undifferentiated SpA (uSpA), diagnosed in 46/106 patients (43.4%). Sacroiliitis was detected by MRI in 21/32 patients with IBP and unclear X-rays (65.6%). Of those, 14 were diagnosed as SpA and seven females with moderate unilateral sacroiliitis, but no features of SpA, also not on follow-up (at least 1 yr), were classified as undifferentiated sacroiliitis (US). Ten of the 14 SpA (71.4%) and none of the seven US patients were HLA B27 positive. HLA B27 positivity in IBP patients with MRI-proven sacroiliitis positively predicts SpA. uSpA is a frequent SpA subset. There are HLA B27-negative non-SpA patients with moderate unilateral sacroiliitis whom we propose to be classified as US.

Injuries to pedestrians in road traffic accidents.

Although there have been many reports on injuries to occupants of cars in road traffic accidents, there have been few prospective studies of injuries to pedestrians in such accidents. For this reason a two year prospective study of pedestrians in road traffic accidents in the Oxford region was carried out. The incidence of death in pedestrians was significantly higher than in car occupants or motorcyclists. The principal determinant of death was the weight of the vehicle concerned. The most common site of injury was the head because of a high incidence of brief concussion, but the most common site of serious injuries was the leg. Injuries to all regions of the body increased with age and with the weight of the vehicle in the collision. Accidents most often concerned young children or the elderly.