Structural damage in rheumatoid arthritis assessed by musculoskeletal ultrasound: A systematic literature review by the Structural Joint Damage Task Force of the OMERACT Ultrasound Working Group

OBJECTIVES

To identify and synthesize the evidence for the use and measurement properties of musculoskeletal ultrasound in assessing structural joint damage in patients with rheumatoid arthritis (RA).

METHODS

A systematic literature search (SLR) of the PubMed, Embase and Cochrane Library was performed. Original articles were included published in English reporting on ultrasound of bone erosion, cartilage damage and the measurement properties of ultrasound according to the OMERACT filter 2.1.

RESULTS

Of the 1.495 identified articles 149 were included in the final review, most of which reported on cross-sectional studies and used the OMERACT definitions for ultrasonographic pathology. Among these, bone erosions were assessed in 139 (93.3%), cartilage damage in 24 (16.1%), enthesophytes in 8 (5.4%), osteophytes in 15 (10.1%) and malalignment and ankylosis in a single (0.9%) study, respectively. Most studies (126/149, 84.6%) assessed the joints of the hands. The overwhelming majority of studies (127/149, 85.2%) assessed structural joint damage bilaterally. Validity, reliability and responsiveness were assessed in 21 (14.1%), 34 (22.8%) and 17 (11.4%) studies, respectively.

CONCLUSION

While the results of this SLR suggest that ultrasound is a sensitive, reliable and feasible tool to detect damage in RA, they also highlight the need for further research and validation. Findings of this SLR will inform the next steps of the OMERACT Ultrasound Working Group in developing an ultrasound score for assessing structural joint damage in patients with RA.

Comorbidity clusters in generalized osteoarthritis among female patients: A cross-sectional study

OBJECTIVES

To investigate the prevalence of comorbidities among female patients with generalized osteoarthritis (GOA) in comparison to an age- and sex matched control group. To identify clusters of comorbidities in both groups.

METHODS

An observational, cross-sectional study was conducted. Consecutive female patients with hand and knee osteoarthritis according to the American College of Rheumatology (ACR) classification criteria were invited to participate in the study. A control group of participants without musculoskeletal symptoms, history or evidence of osteoarthritis or inflammatory rheumatic disease were also included. Cardiovascular, obstructive pulmonary, gastrointestinal, endocrine, neurological, malignant diseases and depression were recorded in both groups. In both study groups comorbidity cluster and factor analysis was performed.

RESULTS

The study population included 200 GOA and 200 control participants. The following comorbidities were observed adjusted to Bonferroni correction with a significantly higher prevalence among individuals with GOA: hypertension, uterine leiomyoma, gastroesophageal reflux disease, diverticulosis, upper gastrointestinal tract ulcers, depression, diseases with vertigo (benign paroxysmal positional vertigo and vertebrobasilar insufficiency) and surgery due to otoclerosis. In the GOA group 5 clusters were identified with different comorbidity patterns.

CONCLUSION

We report a high comorbidity rate in GOA. Cluster analysis allowed us to identify different comorbidity subsets for vascular, gastrointestinal and malignant gynaecological disorders. Further research is required to understand the links between GOA and non-musculoskeletal comorbidities.

Defining enthesitis in spondyloarthritis by ultrasound: results of a Delphi process and of a reliability reading exercise

OBJECTIVE

To standardize ultrasound (US) in enthesitis.

METHODS

An initial Delphi exercise was undertaken to define US-detected enthesitis and its core components. These definitions were subsequently tested on static images taken from spondyloarthritis patients in order to evaluate their reliability.

RESULTS

Excellent agreement (>80%) was obtained for including hypoechogenicity, increased thickness of the tendon insertion, calcifications, enthesophytes, erosions, and Doppler activity as core elementary lesions of US-detected enthesitis. US definitions were subsequently obtained for each elementary component. On static images, the intraobserver reliability showed a high degree of variability for the detection of elementary lesions, with kappa coefficients ranging from 0.13-1. The interobserver kappa values were variable, with the lowest kappa coefficient for enthesophytes (0.24) and the highest coefficient for Doppler activity at the enthesis (0.63).

CONCLUSION

This is the first consensus-based US definition of enthesitis and its elementary components and the first step performed to ensure a higher degree of homogeneity and comparability of results between studies and in daily clinical work.

Ultrasound evaluation of fluid in knee recesses at varying degrees of flexion

OBJECTIVE

Various methods are utilized in daily practice to obtain optimal information on effusion in the knee. Our aim is to investigate which scanning position provides the best information about synovial fluid in the knee by using ultrasound and to evaluate the magnitude of difference for measuring synovial fluid in 3 major recesses (suprapatellar, medial parapatellar, and lateral parapatellar) of the knee according to various degrees of flexion.

METHODS

Sonographers in 14 European centers documented bilateral knee joint ultrasound examinations on a total of 148 knee joints. The largest sagittal diameter of fluid was measured in scans corresponding to the 3 major recesses at different (0°, 15°, 30°, 45°, 60°, and 90°) degrees of flexion of the knee. The difference of measurement of effusion according to transducer position, knee position, and the interaction between them was investigated by analysis of variance followed by Tukey's test.

RESULTS

No correlation was noted between patient characteristics and ultrasound detection of effusion. The sagittal diameter of synovial fluid in all 3 recesses was greatest at 30° flexion. Analysis of variance and Tukey's test revealed that the suprapatellar scan and 30° flexion is the best combination for detecting effusion as confirmed by receiver operator characteristic curve analysis.

CONCLUSION

The suprapatellar scan of the knee in 30° flexion was the most sensitive position to detect fluid in knee joints. Sagittal diameter of fluid in all 3 recesses increased with the knee in the 30° flexed position as compared to the extended position.

Validity of ultrasonography and measures of adult shoulder function and reliability of ultrasonography in detecting shoulder synovitis in patients with rheumatoid arthritis using magnetic resonance imaging as a gold standard

OBJECTIVE

To assess the intra- and interobserver reproducibility of musculoskeletal ultrasonography (US) in detecting inflammatory shoulder changes in patients with rheumatoid arthritis, and to determine the agreement between US and the Shoulder Pain and Disability Index (SPADI) and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, using magnetic resonance imaging (MRI) as a gold standard.

METHODS

Eleven rheumatologists investigated 10 patients in 2 rounds independently and blindly of each other by US. US results were compared with shoulder function tests and MRI.

RESULTS

The positive and negative predictive values (NPVs) for axillary recess synovitis (ARS) were 0.88 and 0.43, respectively, for posterior recess synovitis (PRS) were 0.36 and 0.97, respectively, for subacromial/subdeltoid bursitis (SASB) were 0.85 and 0.28, respectively, and the NPV for biceps tenosynovitis (BT) was 1.00. The intraobserver kappa was 0.62 for ARS, 0.59 for PRS, 0.51 for BT, and 0.70 for SASB. The intraobserver kappa for power Doppler US (PDUS) signal was 0.91 for PRS, 0.77 for ARS, 0.94 for SASB, and 0.53 for BT. The interobserver maximum kappa was 0.46 for BT, 0.95 for ARS, 0.52 for PRS, and 0.61 for SASB. The interobserver reliability of PDUS was 1.0 for PRS, 0.1 for ARS, 0.5 for BT, and 1.0 for SASB. P values for the SPADI and DASH versus cuff tear on US were 0.02 and 0.01, respectively; all other relationships were not significant.

CONCLUSION

Overall agreements between gray-scale US and MRI regarding synovitis of the shoulder varied considerably, but excellent results were seen for PDUS. Measures of shoulder function have a poor relationship with US and MRI. Improved standardization of US scanning technique could further reliability of shoulder US.

Musculoskeletal ultrasound--a state of the art review in rheumatology. Part 2: Clinical indications for musculoskeletal ultrasound in rheumatology

Rheumatologists remain divided on whether they should introduce musculoskeletal ultrasound (MSUS) into their clinical practice. A central issue in the application of MSUS in clinical rheumatology is the need for proof of clinical relevance and improved patient care. There is now accumulating evidence that MSUS improves clinical diagnosis and intervention skills. High-resolution ultrasound is superior to clinical examination in the diagnosis and localization of joint and bursal effusion and synovitis. MSUS is the imaging modality of choice for the diagnosis of tendon pathology. MSUS is seven times more sensitive than plain radiography in the detection of rheumatoid erosions, allowing earlier diagnosis of progressive rheumatoid arthritis. Ligament, muscle, peripheral nerve and cartilage pathology can also be readily demonstrated by MSUS. There is exciting evidence that MSUS may potentially be used by rheumatologists to non-invasively diagnose and monitor not just joint and muscle disease but also nerve compression syndromes, scleroderma, vasculitis and Sjögren's syndrome. Joint aspiration and injection accuracy can be improved by MSUS, with initial evidence confirming improved efficacy. As the number of rheumatologists performing MSUS increases and the technical capabilities of MSUS improve, there is likely to be a growing number of proven clinical indications for the application of MSUS in rheumatology practice. This paper reviews the evidence for the application of MSUS in rheumatology.

Protective effect of sensory denervation in inflammatory arthritis (evidence of regulatory neuroimmune pathways in the arthritic joint)

OBJECTIVE

To investigate the direct effect of joint innervation on immune mediated joint inflammation in a patient with psoriatic arthritis (PsA).

CASE REPORT

The patient developed arthritis mutilans in all digits of both hands with the exception of the left 4th finger, which had prior sensory denervation following traumatic nerve dissection. Plain radiography, ultrasonography and nerve conduction studies of the hands confirmed the absence of articular disease and sensory innervation in the left 4th digit.

METHODS

This relationship between joint innervation and joint inflammation was investigated experimentally by prior surgical sensory denervation of the medial aspect of the knee in six Wistar rats in which carrageenan induced arthritis was subsequently induced. Prior sensory denervation--with preservation of muscle function--prevented the development of inflammatory arthritis in the denervated knee.

DISCUSSION

Observations in human and animal inflammatory arthritis suggest that regulatory neuroimmune pathways in the joint are an important mechanism that modulates the clinical expression of inflammatory arthritis.

Musculoskeletal ultrasound--a state of the art review in rheumatology. Part 1: Current controversies and issues in the development of musculoskeletal ultrasound in rheumatology

As we begin the 21st century, musculoskeletal ultrasound (MSUS) is routinely used by an increasing number of rheumatologists throughout Europe and there is a growing interest in the application of MSUS in rheumatological practice in the UK. MSUS allows high-resolution, real-time imaging of articular and periarticular structures and has the advantages of being non-radioactive, inexpensive, portable, highly acceptable to patients and repeatable. There are a number of critical issues that need to be addressed in order to develop the role of MSUS within rheumatology. These include issues of equipment costs, training and certification and the relationship of rheumatologists and radiologists in advancing the field of MSUS. Rheumatologists must demonstrate the relevance of MSUS in their clinical practice through high-quality research. Emerging technologies such as power Doppler and 3D imaging will further improve imaging capabilities and the range of clinical applications of MSUS systems. This paper reviews how MSUS in rheumatology has evolved and the controversies and issues that rheumatologists must now address in developing MSUS as an indispensable, everyday clinical tool.

Ultrasonography of entheseal insertions in the lower limb in spondyloarthropathy

OBJECTIVE

To compare ultrasonography (US) with clinical examination in the detection of entheseal abnormality of the lower limb in patients with spondyloarthropathy (SpA).

METHODS

35 patients with SpA (ankylosing spondylitis 27; psoriatic arthritis 7; reactive arthritis 1) underwent independent clinical and ultrasonographic examination of both lower limbs at five entheseal sites-superior pole and inferior pole of patella, tibial tuberosity, Achilles tendon, and plantar aponeurosis. US was performed using an ATL (Advanced Technology Laboratories, Bothell, Washington, USA) high definition imaging 3000 machine with linear 7-4 MHz and compact linear 10-5 MHz probes to detect bursitis, structure thickness, bony erosion, and enthesophyte (bony spur). An enthesitis score was formulated from these US findings giving a possible maximum total score of 36.

RESULTS

On clinical examination 75/348 (22%) entheseal sites were abnormal and on US examination 195/348 (56%) sites were abnormal. In 19 entheseal sites with bursitis on US, only five were detected by clinical examination. Compared with US, clinical examination had a low sensitivity (22.6%) and moderate specificity (79.7%) for the detection of enthesitis of the lower limbs. There was no significant correlation between the US score of enthesitis and acute phase parameters such as erythrocyte sedimentation rate (ESR) or C reactive protein (CRP). The intraobserver kappa value for analysis of all sites was 0.9.

CONCLUSIONS

Most entheseal abnormality in SpA is not detected at clinical examination. US is better than clinical examination in the detection of entheseal abnormality of the lower limbs in SpA. A quantitative US score of lower limb enthesitis is proposed but further studies are required to validate it in SpA.

Metacarpophalangeal joints in rheumatoid arthritis: laser Doppler imaging--initial experience

Laser Doppler imaging is a noninvasive method yielding a spatial perfusion map. With use of a near-infrared laser, elevated perfusion associated with the metacarpophalangeal joints was detectable in patients with active rheumatoid arthritis. Findings at laser Doppler imaging correlated with pain scores and synovitis detected at ultrasonography, whereas the power Doppler sign (red pixels inside the active green box) did not. Laser Doppler imaging has the potential to help assess soft-tissue inflammation.

Intraobserver repeatability and interobserver reproducibility in musculoskeletal ultrasound imaging measurements

OBJECTIVE

To assess the repeatability and reproducibility of ultrasonographic measurements at the anterior surface of the femoral neck and iliofemoral ligament and on a human tissue-mimicking phantom.

METHODS

Two independent investigators studied 22 consecutive hips. One investigator had previous experience in musculoskeletal ultrasonography (US). The other investigator had undergone a short course in hip sonography (only 3 hours). Both investigators were blinded to their own and each other's results. On the phantom both observers had taken 10 vertical measurements at 6 cm deep where two objects were placed at 2 cm from each other. Calculation of measurement errors, percent errors and the Bland-Altman graphic technique were used for analysis of data.

RESULTS

After 132 examinations the first investigator's within-subject standard deviation was 0.4 mm. The intraobserver error was 4.75%. The second investigator's within-subject standard deviation was 0.6 mm and his intraobserver error was 7.00%. The interobserver error was 10.91%. After 20 phantom examinations the first investigators's intraobserver error was 1.11% and the second investigator's intraobserver error was 1.47%.

CONCLUSION

An inexperienced musculoskeletal sonographer can achieve an acceptable performance if given appropriate training.

Inflamed retrocalcaneal bursa and Achilles tendonitis in psoriatic arthritis demonstrated by ultrasonography

OBJECTIVE

To demonstrate the use of high resolution ultrasound measurements and power Doppler mode in the diagnosis and follow up of a patient with psoriatic arthritic with retrocalcaneal bursitis and Achilles tendonitis.

METHODS

An outpatient based ATL HDI 3000 ultrasound equipment was used with a CL10-5 MHZ 26 mm probe and musculoskeletal software. Real time B mode and power Doppler mode were used to detect changes in structure and blood flow.

RESULTS

Unilateral retrocalcaneal bursitis and Achilles tendonitis were demonstrated by sonography. Power Doppler mode was useful to demonstrate an increased blood flow around an abnormal retrocalcaneal bursa. A follow up examination showed marginal thickening of the Achilles tendon without any bursitis.

CONCLUSIONS

Ultrasonography is an objective method in the confirmation of clinical diagnosis after physical examination. During the examination it is possible to gain not only qualitative but also quantitative data. A comparative study with quantitative data is possible in longitudinal studies.

Novel use of laser Doppler imaging for investigating epicondylitis

OBJECTIVE

This investigation evaluated a novel form of tissue perfusion measurement, laser Doppler imaging (LDI), in a case of lateral epicondylitis to establish if it might have applications in assessing soft tissue lesions. LDI was used in conjunction with ultrasonography to provide information about tissue oedema as well as the power Doppler signal as an alternative method of assessing blood flow.

METHODS

A laser Doppler imager with a near-infrared (NIR) laser source was used to improve tissue penetration and yield measurements of perfusion (flux) from structures under the skin. Skin temperature over the lateral epicondylar region was also measured. Ultrasonography was used in both grey-scale and power Doppler modes. LDI, temperature measurements and ultrasonographic data were obtained before treatment and serially after local injection of methylprednisolone.

RESULTS

Before treatment there was increased perfusion and skin temperature and the presence of a power Doppler sign associated with the right lateral epicondyle as well as oedema at the extensor origin. None of these was present at the asymptomatic contralateral epicondylar region. Twenty-four hours after methylprednisolone administration, both perfusion and skin temperature had increased, and they declined over the subsequent 48 h. Although skin temperature had declined to normal (referenced to the contralateral epicondyle) by the third day after injection, it took until the eleventh day after injection for perfusion to normalize.

CONCLUSIONS

LDI using an NIR laser source appears to be an effective non-invasive method for the examination of inflammatory responses in soft tissue, with greater sensitivity than thermally based methods. In addition, LDI was found to correlate with power Doppler ultrasonography.