Sonographic-detected joint effusion compared with physical examination in the assessment of sacroiliac joints in spondyloarthritis

How to inject sacroiliac joints with ultrasound guidance: a pictorial essay

Active sacroiliitis and sacroiliac joint dysfunction represent a common cause of low back pain in the population and are cause of patients' quality of life reduction and disability worldwide. The use of musculoskeletal ultrasound allows to easily identify the sacroiliac joints and to study every pathological condition affecting its most dorsal part; moreover, musculoskeletal ultrasound allows to guide highly effective injective procedures aimed at improving patients' symptoms and enhance their well-being. This paper aims to briefly explain for the musculoskeletal sonographer the anatomy and biomechanics of the sacroiliac joints, the correct ultrasound scanning method for their visualization and the most appropriate ultrasound guided injection technique to help dealing with the diagnostic and management of sacroiliac joint pain in the everyday scenario.

Ultrasound-guided intra-articular corticosteroid injection in a patient with manubriosternal joint involvement of ankylosing spondylitis: A case report

BACKGROUND

Manubriosternal joint (MSJ) disease is a rare cause of anterior chest pain but can be a major sign of systemic arthritic involvement. In patients with ankylosing spondylitis (AS), a type of systemic arthritis, chest pain can be due to MSJ involvement and can be improved by ultrasound-guided corticosteroid injection into the joint.

CASE SUMMARY

A 64-year-old man visited our pain clinic complaining of anterior chest pain. There were no abnormal findings on lateral sternum X-ray, but arthritic changes in the MSJ were observed on single-photon emission computed tomography-computed tomography. We performed additional laboratory tests, and he was finally diagnosed with AS. For pain relief, we performed ultrasound-guided intra-articular (IA) corticosteroid injections into the MSJ. After the injections, his pain nearly resolved.

CONCLUSION

For patients complaining of anterior chest pain, AS should be considered, and single-photon emission computed tomography-computed tomography can be helpful in diagnosis. In addition, ultrasound-guided IA corticosteroid injections may be effective for pain relief.

Suggested Applications of Musculoskeletal Ultrasound to Identify the Etiologies of Low Back Pain

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Power and spectral Doppler ultrasound in suspected active sacroiliitis: a comparison with magnetic resonance imaging as gold standard

OBJECTIVES

The objectives of this study were to study with Power Doppler US (PDUS) the SI joints (SIJs) of patients with suspected active sacroiliitis, to describe SIJ flows with spectral wave analysis (SWA) on Doppler US, and to correlate US data with both clinical characteristics and presence of SIJ bone marrow oedema (BME) in subsequent MRI.

METHODS

A total of 42 patients (32 females and 10 males, mean age 46.8 years) with recent onset of inflammatory back pain (IBP) were included. Every patient underwent US examination with a convex 1-8 MHz probe [scoring PDUS signals with a three-point scale and describing flows in SWA calculating the mean Resistive Index (RI)] and subsequent MRI of the SIJs.

RESULTS

PDUS signals were detected in 34 patients and 62 SIJs. In 29 patients and 56 SIJs, MRI revealed BME. A definite diagnosis of SpA was made in 32 patients. PDUS signals were more frequent (P < 0.0001) in patients with a final diagnosis of SpA, yielding a higher PDUS score (P = 0.0304). PDUS grading correlated with both BME grading (r = 0.740, P = 0.0001) and AS DAS (ASDAS) (r = 0.6257, P = 0.0004), but not with inflammatory reactants nor anthropometric data. Mean RI were, respectively, 0.60 and 0.73 (P < 0.0001) in patients with or without diagnosis of active sacroiliitis. The most inclusive RI cut-off resulted <0.70 [positive predictive value (PPV) 94%, accuracy 90%, P = 0.0001]. The best Likelihood Ratio (5.471) for RI to detect pathologic cases was obtained with a cut-off of <0.60 (PPV 96%).

CONCLUSIONS

PDUS and SWA of SIJs demonstrate good diagnostic accuracy for active sacroiliitis compared with MRI.

Value of Color Doppler Ultrasound Assessment of Sacroiliac Joints in Patients with Inflammatory Low Back Pain

OBJECTIVE

To evaluate the diagnostic value of color Doppler ultrasound (CDUS) for the detection of sacroiliitis, in patients with inflammatory back pain (IBP).

METHODS

Consecutive patients with IBP and suspected axial spondyloarthritis (SpA), but without a definitive diagnosis, were included. Consecutive patients with defined SpA and axial involvement were included as a control group. All patients underwent clinical evaluation, magnetic resonance imaging (MRI), and CDUS of sacroiliac joints (SIJ) within the same week. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the diagnosis of sacroiliitis by CDUS were calculated, using MRI as the gold standard.

RESULTS

There were 198 SIJ evaluated in 99 patients (36 with previous SpA). There were 61 men (61.6%), with a mean age of 39.8 years (SD 11.3) and median disease duration of 24 months (IQR 12-84). At the patient level, CDUS had a sensitivity of 63% (95% CI 48.7-75.7%) and a specificity of 89% (95% CI 76-96%). The PPV was 87.2% (95% CI 72.6-95.7%) and the NPV was 66.7% (95% CI 53.3-78.3%). At joint level, CDUS had a sensitivity of 60% (95% CI 49-70%) and a specificity of 93% (95% CI 88-98%). The PPV was 83% (95% CI 78-95%) and the NPV was 43% (95% CI 33-56%). The sensitivity of CDUS for the diagnosis of axial SpA was 54% (95% CI 36.6-71.2%), specificity was 82% (95% CI 63.1-93.9%), PPV was 79% (95% CI 57.8-92.9%), and NPV was 59% (95% CI 42.1-74.4%).

CONCLUSION

CDUS showed adequate diagnostic properties for detection of sacroiliitis and is a useful tool in patients with IBP.

Ultrasound of sacroiliac joints in spondyloarthritis: a systematic review

Ultrasound (US) is an accessible imaging technique with a possible role to diagnose active sacroiliitis, so this technique is projected as a promising diagnostic tool for the diagnosis of SpA. We analyse the available evidence about the use of US as a diagnostic tool in sacroiliitis in patients with SpA, by a systemic review of the literature fulfilling OMERACT criteria. A systematic literature search for original articles was carried out using four databases (Medline, Embase, Scopus and Web of Science). Data from studies were included only if participants had SpA and a US examination of sacroiliac joint (SIJ) was performed. The methodological quality of the studies was assessed using QUADAS-2 tool. Thirteen studies were included. All studies were observational, prospective and cross-sectional. In most articles (76.9%), the main US finding compatible with sacroiliitis evaluated was the presence of vascularisation (Doppler signals) with measurements of the resistive index (RI). The sensitivity and specificity analysis were performed in seven studies (58.8%) and were good, with a median of 90 and 89.2%, respectively. The studies showed a positive to moderate a strong correlation between the US and the gold standard but this was optimal only in four studies. In general, the agreement was good in all studies (≥ 0.80). The methods of evaluation of sacroiliitis vary between the studies included. To date, there is not enough evidence to support the use of ultrasound as a diagnostic method for sacroiliitis but it has potential to identify structural lesions at SIJ's level.

The Role of Imaging in Diagnosing Axial Spondyloarthritis

Imaging has a central role in the diagnosis, management, and follow-up of patients with axial spondyloarthritis (axSpA). For the early diagnosis of axSpA, magnetic resonance imaging is of utmost relevance. While no novel imaging techniques were developed during the past decade, improvements to the existing modalities have been introduced. This report provides an overview of the applications and limitations of the existing imaging modalities.

Color Doppler and spectral Doppler ultrasound detection of active sacroiliitis in spondyloarthritis compared to physical examination as gold standard

Sacroiliac joint (SIJ) involvement is a distinctive feature of spondyloarthritis (SpA). The main objective of this study was to assess the validity of color Doppler ultrasound (CDUS) in SIJ. This was a cross-sectional, blinded, case-control study of 108 cases divided into three groups: (a) 53 SpA patients with inflammatory back pain (IBP); (b) 28 SpA patients with no IBP; and (c) 27 healthy mechanical lumbar pain subjects. Physical examinations of the SIJs were assessed as positive or negative in each SIJ and were used as the gold standard. SIJs were examined with CDUS and spectral Doppler, and the SIJs were assessed as positive when both color Doppler and the resistance index (RI) were less than the cut-off point within the SIJs area. A total of 108 cases (53 female; mean age 36 ± 10 years old) were studied. The physical examination of the SIJs was positive in 38 patients (59 SIJs). Ultrasound detected Doppler signal within the SIJs in 37 cases (58 SIJs): 33 of them had symptomatic SpA (52 SIJs), 3 of them had asymptomatic SpA (5 SIJs), and 1 was a healthy control (1 SIJ). The accuracy of CDUS, when compared to physical SIJ examination, at the patient level in the overall group had a sensitivity of 70.3%, a specificity of 85.7%, a positive likelihood ratio of 4.9, and a negative likelihood ratio of 0.36. For the spectral Doppler RI, with an optimal cut-off point ≤0.75, the sensitivity was 76.2%, and the specificity was 77.8%. CDUS of SIJs seems to be a feasible and valid method for detecting active inflammation in patients with SpA.

Diffusion-weighted imaging is a sensitive biomarker of response to biologic therapy in enthesitis-related arthritis

Objective

The aim was to evaluate diffusion-weighted imaging (DWI) as a tool for measuring treatment response in adolescents with enthesitis-related arthropathy (ERA).

Methods

Twenty-two adolescents with ERA underwent routine MRI and DWI before and after TNF inhibitor therapy. Each patient's images were visually scored by two radiologists using the Spondyloarthritis Research Consortium of Canada system, and sacroiliac joint apparent diffusion coefficient (ADC) and normalized ADC (nADC) were measured for each patient. Therapeutic clinical response was defined as an improvement of ⩾ 30% physician global assessment and radiological response defined as ⩾ 2.5-point reduction in Spondyloarthritis Research Consortium of Canada score. We compared ADC and nADC changes in responders and non-responders using the Mann-Whitney-Wilcoxon test.

Results

For both radiological and clinical definitions of response, reductions in ADC and nADC after treatment were greater in responders than in non-responders (for radiological response: ADC: P < 0.01; nADC: P = 0.055; for clinical response: ADC: P = 0.33; nADC: P = 0.089). ADC and nADC could predict radiological response with a high level of sensitivity and specificity and were moderately sensitive and specific predictors of clinical response (the area under the receiver operating characteristic curves were as follows: ADC: 0.97, nADC: 0.82 for radiological response; and ADC: 0.67, nADC: 0.78 for clinical response).

Conclusion

DWI measurements reflect the response to TNF inhibitor treatment in ERA patients with sacroiliitis as defined using radiological criteria and may also reflect clinical response. DWI is more objective than visual scoring and has the potential to be automated. ADC/nADC could be used as biomarkers of sacroiliitis in the clinic and in clinical trials.

Recommendations for the Use of Ultrasound and Magnetic Resonance in Patients With Spondyloarthritis, Including Psoriatic Arthritis, and Patients With Juvenile Idiopathic Arthritis

OBJECTIVE

To develop evidence-based recommendations on the use of ultrasound (US) and magnetic resonance imaging in patients with spondyloarthritis, including psoriatic arthritis, and juvenile idiopathic arthritis.

METHODS

Recommendations were generated following a nominal group technique. A panel of experts (15 rheumatologists and 3 radiologists) was established in the first panel meeting to define the scope and purpose of the consensus document, as well as chapters, potential recommendations and systematic literature reviews (we used and updated those from previous EULAR documents). A first draft of recommendations and text was generated. Then, an electronic Delphi process (2 rounds) was carried out. Recommendations were voted from 1 (total disagreement) to 10 (total agreement). We defined agreement if at least 70% of participants voted≥7. The level of evidence and grade or recommendation was assessed using the Oxford Centre for Evidence Based Medicine levels of evidence. The full text was circulated and reviewed by the panel. The consensus was coordinated by an expert methodologist.

RESULTS

A total of 12 recommendations were proposed for each disease. They include, along with explanations of the validity of US and magnetic resonance imaging regarding inflammation and damage detection, diagnosis, prediction (structural damage progression, flare, treatment response, etc.), monitoring and the use of US guided injections/biopsies.

CONCLUSIONS

These recommendations will help clinicians use US and magnetic resonance imaging in patients with spondyloarthritis and juvenile idiopathic arthritis.

An atypical limping teenager

A 13-year-old boy presented with a 5-day history of left-sided limp of gradual onset. There was no history of trauma. He developed a fever and rigours a few days before presenting to the paediatric emergency department. On examination, he was tender on palpating the left gluteal area on active mobilisation of the left hip and could not weight bear on the left leg. Pelvic X-rays and ultrasound of the left hip were normal. The blood results showed raised inflammatory markers and normal white cell count. The blood cultures were positive for Staphylococcus aureus. On day 2, a left hip MRI was performed as well as CT-guided drainage. Diagnosis of left sacroiliac septic arthritis was made. After an initial lack of improvement under intravenous ceftriaxone, a drain was inserted and left in situ for 8 days with double intravenous antibiotic therapy instituted. The patient made a full recovery.

Doppler US in rheumatic diseases with special emphasis on rheumatoid arthritis and spondyloarthritis

Developments in digital ultrasonography (US) technology and the use of high-frequency broadband transducers have increased the quality of US imaging, particularly of superficial tissues. Thus, US, particularly color US or power Doppler US, in which high-resolution transducers are used, has become an important imaging modality in the assessment of rheumatic diseases. Furthermore, therapeutic interventions and biopsies can be performed under US guidance during the assessment of lesions. In this era of effective treatments, such as biologics, improvements in synovial inflammation in rheumatoid arthritis as well as changes in enthesitis in spondyloarthropathies, including ankylosing spondylitis and psoriatic arthritis, can be monitored effectively using gray-scale and/or power Doppler US. US is also a good imaging modality for crystal arthropathies, including gout and pseudogout, in which synovitis, erosions, tophi, and crystal deposition within or around the joint can be visualized readily. Vascular and tenosynovial structures, as well as the salivary glands, can be assessed with US in vasculitis and connective tissue disorders, including systemic lupus erythematosus and Sjögren's syndrome. Current research is focused on improving the sensitivity, specificity, validity, and reproducibility of US findings. In this review, we summarized the role of US, particularly power Doppler US, in rheumatic diseases and inflammation in superficial tissues.

The role of ultrasound in diagnosis of the causes of low back pain: a review of the literature

Context:

Low back pain (LBP) is among the most prevalent musculoskeletal conditions in the developed countries. It is a common problem causing disability and imposing a huge economic burden to individuals and state organizations. Imaging plays an important role in diagnosis of the etiology of LBP.

Evidence Acquisition:

The electronic databases included: PubMed (1950 to present), Ovid SP Medline (1950 to present) and ISI (1982 to present) and Google Scholar. In every search engine another search was performed using various permutations of the following keywords: ultrasonography, ultrasound imaging, low back pain, back muscles, paraspinal muscles, multifidus, transverse abdominis, muscle size, spinal canal, sacroiliac joint and spondylolisthesis.

Results:

Magnetic resonance imaging (MRI) is widely used in evaluation of patients with LBP; however, high costs, limited availability and contraindications for its use have restricted MRI utilization. In a quest for a less expensive and readily available tool to investigate LBP, clinicians and researchers found ultrasonography (US) as an alternative. In this review we discuss the US application in diagnosis of some common causes of non-specific chronic LBP. Discussed topics include evaluation of spinal canal diameter, paraspinal and transabdominal muscles, sacroiliac joint laxity, pregnancy related LBP, sacroiliitis, and spondylolisthesis using US in patients with LBP.

Conclusions:

While the first researches on employing ultrasound in diagnosis of patients with LBP had been focused on spinal canal diameter, recent studies have been mostly performed to evaluate the role of transabdominal and paraspinal muscles on core stability and thereby LBP occurrence. On the other side, Doppler ultrasonography has recently played an important role in objective measurement of joint laxity as a common etiology for LBP. Doppler imaging also in pregnant patients with LBP has been recommended as a safe and sensitive method. As conclusion, according to recent and most prestigious studies, focusing more on transabdominal muscle thickness can be considered as future approach in investigations.

Clinical and radiological evaluation of sacroiliac joints compared with ultrasound examination in early spondyloarthritis

OBJECTIVE

To compare clinical and X-ray examinations with US findings of SI joints (SIJ) in early SpA patients.

METHODS

Twenty-three early SpA patients, diagnosed according to Assessment of SpondyloArthritis international Society criteria, were investigated clinically [sacral sulcus tenderness, BASMI, BASFI, BASDAI, pain and fatigue visual analogue scale (VAS), morning stiffness and sleep disturbance], with SIJ X-rays (New York score) and with My Lab70 US 7-10 MHz US (Esaote, Genoa, Italy), evaluating the width of the SIJ capsule and posterior sacroiliac (PSL) and sacrotuberosus (STL) ligament thickness and comparing the results with 23 healthy controls.

RESULTS

SIJ width [right 2.2 (0.6) and left 2.3 (0.7) in SpA vs 1.6 (0.1) and 1.7 (0.2) in healthy controls, respectively, expressed as mean (s.d.)] and STL thickness [right 3.9 (1.3) and left 3.4 (1.0) vs 1.8 (0.1) and 1.8 (0.1), respectively, expressed as mean (s.d.)] were higher in SpA patients than in controls (P < 0.001 and P < 0.05, respectively). PSL thickness was similar in patients and controls. Only STL thickness was higher when SIJ was tender at clinical examination (P < 0.01) and correlated with pain VAS (P < 0.001) and BASFI (P < 0.05). Furthermore, SIJ US results were unrelated to X-ray findings (similar when X-ray sacroiliitis was present and not).

CONCLUSION

Our exploratory study suggested that in early SpA patients US might be a promising method, complementary to other imaging techniques, to study articular and soft tissue periarticular involvement of SIJ, independent of clinical and X-ray examination.

MRI and ultrasonography for diagnosis and monitoring of psoriatic arthritis

Imaging techniques such as magnetic resonance imaging (MRI) and ultrasound (US) have been increasingly used in psoriatic arthritis (PsA) providing additional clues to the pathogenesis of this peripheral, axial and dermatologic disease. This has improved our understanding of the disease and can be used to aid diagnosis and then to follow outcomes of treatment. Both imaging modalities have highlighted the differing involvement of PsA when compared with rheumatoid arthritis (RA) with a significant burden of entheseal disease, flexor tenosynovitis (occurring alone or as part of dactylitis) and other extra-capsular inflammatory changes. MRI scanning has also highlighted the link between the nail and the distal interphalangeal (DIP) joint confirming previous clinical observations. Imaging studies in psoriasis patients have discovered a high level of subclinical inflammatory change but the clinical importance of such findings has not yet been defined. The potential use of MRI and US to monitor treatment outcomes has encouraged research in this field. In MRI, the PsA MRI Score (PsAMRIS) has been developed with promising initial validation. In US, work is ongoing with the OMERACT group to define key pathologies and to develop scoring systems. A few scoring systems are available for enthesitis scoring using US which are further being developed and refined. Further improvements in technologies in both of these fields offer exciting possibilities for future research. New MRI techniques offer the chance to image previously 'dark' structures such as tendons which is key in spondyloarthritides (SpA). Sonoelastography may also improve our understanding of tendon involvement in SpA. Whole-body multi-joint MRI allows a 'snapshot' of inflammation in PsA including joints, entheses and spinal involvement. Three-dimensional US should improve reliability and comparability of US scoring reducing inter-operator variability. The latest machines offer real-time fusion imaging employing US machines with an in-built virtual navigator system linked to previous MRI acquisitions. All of these new techniques should aid our understanding of PsA and our ability to objectively measure response to therapy.

Ultrasound applications for the practicing rheumatologist

Musculoskeletal ultrasound is an increasingly used tool for the evaluation and management of rheumatologic diseases. Its utilisation by rheumatologists is varied around the world and is dependent upon training and local expertise. Its applications can be broadly categorised into three main areas; for the education of patients, to aid the rheumatologist in the diagnosis and monitoring of disease, and therapeutically for joint aspiration and injection. Ultrasound is a safe, portable, easily repeatable, dynamic images in multiple planes and cheap form of imaging. Ultrasound however, is operator dependent and has a number of artefacts that can result in misinterpretation. Musculoskeletal Ultrasound uses a number of modes to characterise joint pathology, including grey scale, colour and power Doppler, spectral Doppler, 3D imaging, elastography. Musculoskeletal ultrasound can detect and monitor multiple joint pathologies including synovitis, tenosynovitis, and tendon pathologies, entheseal processes, bone erosions and osteophytes, cartilage changes and bursal pathologies.

Juvenile spondyloarthropathies

Spondyloarthropathy (or spondyloarthritis) can begin in childhood (defined as individuals less than 16 years of age). These diseases are distinct in childhood, when compared with adult-onset disease. Because of overlapping features, especially sacroiliac joint involvement, diagnostic difficulty may arise from Behcet's disease, as well as familial Mediterranean fever. Despite advances in diagnostic techniques such as magnetic resonance imaging, the diagnosis of juvenile spondyloarthropathy may still be delayed many years from the onset of symptoms. Treatment of juvenile spondyloarthropathy has advanced rapidly in the last several years, with increasing evidence that agents targeting tumor necrosis factor are effective. These agents also have serious complications, including induction of other autoimmune diseases.

Recent advances in imaging in psoriatic arthritis

The recent introduction of effective therapies in psoriatic arthritis (PsA) has increased the demand for efficient tools for diagnosis, monitoring and prognostication of PsA, and has caused an increased research effort within imaging in this disease. The clinical appearance of PsA is very diverse, involving the spine, sacroiliac joints, peripheral joints and/or entheses, and accordingly imaging findings vary. In the present paper, we present a review of the recent advances in imaging in PsA, focusing primarily on ultrasonography and magnetic resonance imaging of peripheral disease manifestations.

Diagnosis and treatment of enthesitis-related arthritis

Juvenile idiopathic arthritis (JIA) is a chronic, inflammatory disease of unknown etiology. The enthesitis-related arthritis (ERA) JIA category describes a clinically heterogeneous group of children including some who have predominately enthesitis, enthesitis and arthritis, juvenile ankylosing spondylitis, or inflammatory bowel disease-associated arthropathy. ERA accounts for 10%–20% of JIA. Common clinical manifestations of ERA include arthritis, enthesitis, and acute anterior uveitis. Axial disease is also common in children with established ERA. Treatment regimens for ERA, many of them based on adults with rheumatoid arthritis and ankylosing spondylitis, include the use of nonsteroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs, and biologic agents either individually or in combination.

[Present and future of echography in spondyloarthritis]

Today ultrasound in spondyloarthritis is being developed in three main areas. Joint ultrasound is similar to that described in rheumatoid arthritis and other synovitis, with extensive literature on the matter. Enthesis ultrasound has a growing number of publications that describe the main elementary lesions. Several ultrasound enthesis scores have been developed that provide an overall view of the patient status and this information is useful both in the field of diagnosis and in assessing disease activity. The sacroiliac joints have also received attention and the published sensitivity and specificity could be useful in clinical practice. The future is unknown, but ultrasound has many possibilities that include improving the reliability, the incorporation of enthesis ultrasound assessment to the diagnostic classification criteria as well as the likelyhood developing simplified scores.

Identification of the Clinical Features Distinguishing Psoriatic Arthritis and Fibromyalgia

Objective.

To identify the clinical features that can help to distinguish between psoriatic arthritis (PsA) and fibromyalgia (FM).

Methods.

Our cross-sectional study was carried out in 10 Italian rheumatology centers between January and September 2009, and enrolled all consecutive patients with PsA and FM who agreed to participate. Standard clinical and laboratory data for PsA and FM were collected from all patients. Records were made of somatic symptoms, response to nonsteroidal antiinflammatory drugs (NSAID), self-evaluated pain, general health, disability, and responses to the Fibromyalgia Impact Questionnaire. Data were statistically analyzed by univariate and multivariate analyses, and receiver-operating characteristic curves. The analysis concentrated on the clinical features shared by the 2 conditions.

Results.

Two hundred sixty-six patients with PsA (mean age 51.7 yrs; disease duration 10.2 yrs) and 120 patients with FM (mean age 50.2 yrs; disease duration 5.6 yrs) were evaluated. Univariate analysis showed that patients with FM had higher mean tender point and enthesitis scores, more somatic symptoms, and responded less to NSAID. Multivariate analysis showed that the presence of ≥ 6 FM-associated symptoms and ≥ 8 tender points was the best predictor of FM.

Conclusion.

The shared clinical features of PsA and FM that had the greatest discriminating power for FM were the number of FM-associated symptoms and tender point count.

Enthesitis in an inception cohort of enthesitis-related arthritis

OBJECTIVE

To describe an enthesitis-related arthritis (ERA) inception cohort and determine which entheses and joints are most commonly affected.

METHODS

We reviewed a retrospective inception cohort study of children with ERA who were diagnosed and treated at The Children's Hospital of Philadelphia between November 2007 and December 2009.

RESULTS

During the study period, there were 32 newly diagnosed ERA patients. Fifty-nine percent were male, and the median age at the date of initial evaluation was 12.5 years (interquartile range [IQR] 10.2-14.3 years). The median number of tender entheses at presentation was 2 (IQR 0-5), and 21 subjects (66%) had at least 1 tender enthesis. The most prevalent tender entheses were the patellar ligament insertion at the inferior pole of the patella, the plantar fascial insertion at the calcaneus, the Achilles tendon insertion at the calcaneus, and the plantar fascial insertion at the metatarsal heads. Enthesitis was most often symmetric. The median number of active joints was 2 (IQR 0-4). The most commonly affected joints were the sacroiliacs, knees, and ankles. Sacroiliitis, which was defined clinically, was most often symmetric, while peripheral arthritis was most frequently asymmetric. The odds of having active enthesitis at 6 months increased significantly with each additional tender enthesis at the initial evaluation.

CONCLUSION

Among pediatric patients with ERA, lower extremity enthesitis is prevalent at the time of diagnosis and is likely to persist 6 months later. Future studies should address standardization of the enthesitis examination, the pattern of enthesitis over time, enthesitis response to therapy, and the impact of enthesitis on quality of life.

Spondyloarthritis in a pediatric population: risk factors for sacroiliitis

OBJECTIVE

Pediatric rheumatologists may have an opportunity to diagnose sacroiliitis in its early stages, prior to the development of irreversible radiographic changes. Early diagnosis frequently requires magnetic resonance imaging (MRI), the use of which is limited by expense and requirement for sedation. We set out to identify features of juvenile spondyloarthritis (SpA) associated with the highest risk of sacroiliitis, to identify patients who may be candidates for routine MRI-based screening.

METHODS

We reviewed the charts of 143 children seen at Texas Scottish Rite Hospital for Children diagnosed with SpA based on the International League of Associations for Rheumatology criteria for enthesitis-related arthritis or the Amor criteria for SpA. We performed logistic regression analysis to identify risk factors for sacroiliitis.

RESULTS

A group of 143 children were diagnosed with SpA. Consistent with the diagnosis of SpA, 16% had psoriasis, 43% had enthesitis, 9.8% had acute anterior uveitis, and 70% were HLA-B27+. Fifty-three children had sacroiliitis, of which 11 cases were identified by imaging studies in the absence of suggestive symptoms or physical examination findings. Logistic regression analysis revealed that hip arthritis was a positive predictor of sacroiliitis, while dactylitis was a negative predictor.

CONCLUSION

Children with SpA are at risk for sacroiliitis, which may be present in the absence of suggestive symptoms or physical examination findings. The major risk factor for sacroiliitis is hip arthritis, while dactylitis may be protective. Routine screening by MRI should be considered in patients at high risk of developing sacroiliitis.

Utility of bedside sonography to distinguish soft tissue abnormalities from joint effusions in the emergency department

OBJECTIVE

The purpose of this study was to determine the utility of bedside sonography to differentiate soft tissue abnormalities from joint effusions.

METHODS

We conducted a retrospective review of emergency department (ED) patients presenting with joint pain, erythema, and swelling who received bedside sonography. The ED sonographic examinations were performed by emergency physician sonologists who were not involved in clinical assessment and management of these patients. The treating physician's opinions regarding the probability of joint effusion and need for aspiration were documented in the sonography log before the sonographic examination was performed. The bedside sonograms of all patients included in this study were also reviewed for accuracy. Descriptive statistics were used to summarize the data.

RESULTS

A total of 54 patients (mean age +/- SD, 41 +/- 18.9 years) were identified over a 1-year period. The symptomatic joints in our study subjects were as follows: knee, 24 of 54 (44%); elbow, 21 of 54 (38%); ankle, 8 of 54 (15%); and metatarsophalangeal joint, 1 of 54 (2%). Twenty-two of 54 patients (40.7%; 95% confidence interval [CI], 27.6%-53.8%) were found to have joint effusions on sonography. Sonography altered management in 35 of 54 patients (65%; 95% CI, 52%-77.5%). Joint aspiration was planned in 39 of 54 cases (72.2%; 95% CI, 60.2%-84.1%) before sonography. After sonography, only 20 of these patients (37%; 95% CI, 24.1%-49.9%) underwent joint aspiration. There was a statistically significant difference in treatment plans after the addition of bedside sonographic results (P < .01).

CONCLUSIONS

Our study suggests that bedside sonography is useful in differentiating joint effusions from soft tissue abnormalities and directing appropriate therapy.

[Ultrasound scores in spondyloarthritis]

Ultrasound is proving its validity in the assessment of patients with spondyloarthritis. This paper reviews the various indices validated for the quantification of the activity or for the diagnosis of involvement of peripheral joints, enthesis and sacroiliac joints of these patients. The studies are still preliminary but point to future uses of ultrasound in spondyloarthritis.

Imaging of the sacroiliac joint involvement in seronegative spondylarthropathies

Involvement of the sacroiliac joints is the first predominant finding of all seronegative spondylarthropathies (SpA) subsets, such as ankylosing spondylitis, psoriatic arthritis, and undifferentiated SpA. Although conventional radiography is indicated in the initial evaluation of sacroiliac joints diseases, it is often insensitive for demonstrating the early changes of sacroiliitis, so other imaging techniques typically are often necessary to clarify the pathology and for establishing the early diagnosis of seronegative SpA. Other imaging modalities, including computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US), and bone scintigraphy have improved visualization of inflammatory changes at the sacroiliac joints (SIJ). CT scans are indicated for disease processes in which bony destruction or ossification may occur. MRI has been proposed as an imaging method to detect sacroiliitis earlier. MRI can identify both inflammation and structural changes caused by inflammation, while radiographs show only structural changes. MRI may be particularly useful in making a diagnosis of SpA. Musculoskeletal US has an increasing and relevant role in the evaluation of SpA mainly for its ability to assess joint and periarticular soft tissue involvement and in particular for its capacity to detect enthesitis. US assessment in general is safe, noninvasive, and comparably cheap, showing itself as a complimentary tool to clinical evaluation in SpA; nevertheless, it is very user dependent. Bone scintigraphy is at most of limited diagnostic value for the diagnosis of established AS, including the early diagnosis of probable/suspected sacroiliitis. The main aim of this study is to introduce the clinical and radiological aspects of the SIJ involvement in SpA, particularly the contribution of the different imaging techniques.