Ultrasound helps localize ankle inflammation in juvenile arthritis
Ultrasound can assist clinical examinations in precisely identifying inflamed sites in ankles among patients with juvenile idiopathic arthritis, according to findings published in Arthritis Care & Research.
“Clinical evaluation (CE) of the ankle is often challenging even for expert pediatric rheumatologists, especially in young patients, owing to the presence of numerous joints and tendons, and the physiological abundant fat,” Stefano Lanni, MD, PhD, of the Policlinico of Milan, in Italy, and colleagues wrote. “These issues explain, at least in part, why signs and symptoms of disease including pain, swelling and impaired joint mobility may be related with difficulty to the involvement of a specific joint of the ankle region with CE.”
“Over the last few years, there has been an expanding application of ultrasound (US) in the management of JIA,” they added. “The high acceptability by patients, the lack of exposure to ionizing radiation, the noninvasiveness and the ability to allow real-time and multiplane imaging of joints and tendons make this imaging technique particularly suitable for the assessment of children with chronic inflammatory arthritis.”
To compare the frequency of joint and tendon disease identified using ultrasound with those identified using clinical examinations, and to analyze the agreement between the two methods regarding ankles with active JIA, Lanni and colleagues studied juvenile patients recruited from the IRCCS Ospedale Maggiore Policlinico of Milan, Italy. Ultrasound and clinical examinations were independently performed in the joint and tendon compartments in 105 ankles.
Data recorded at each patient’s clinical examination included sex, age at disease onset and at study entry, disease duration, ILAR category, antinuclear antibody status and ongoing medications. The researchers defined clinical active JIA as the presence of swelling, or tenderness or pain on motion, and restricted motion in at least one of the ankle joints. Clinical exams also assessed concomitant inflammation in tendons of the anterior, medial and lateral compartments.
Further, investigators scored grayscale and power Doppler ultrasound joint abnormalities on a 4point semiquantitative scale. A joint with a gray-scale score of at least 2 and/or a power Doppler score of at least 1 was classified as active. The researchers used kappa statistics to test agreement.
According to the researchers, ultrasound revealed active synovitis in 163 joints across 89 ankles. The most commonly affected joint on both ultrasound and clinical examination was the tibiotalar joint, followed by the intertarsaljoint, on ultrasound, and the subtalar joint, in clinical examination. Investigators found tenosynovitis in 70.5% of ultrasound assessments, compared with 32.4% in clinical examinations, and was more frequent in the medial and lateral than in the anterior tendon compartments. Ultrasound detected isolated tenosynovitis 12 ankles.
Agreement between the two methods for detecting active synovitis and tenosynovitis was “less than acceptable,” (k < 0.4), the researchers wrote. There was no correlation between any feature of active disease recorded on clinical examinations and active synovitis on ultrasound in the tibiotalar, subtalar or intertarsal joints.
“Despite the application of a score aimed to identify with greater accuracy the presence of active joint synovitis on [ultrasound], we did not find satisfactory agreement between clinical and [ultrasound] assessment of the ankle region in our patients with JIA,” Lanni and colleagues wrote. “Our observation suggests that [clinical evaluation] does not allow a proper evaluation of ankle disease activity, as it is not able to establish precisely the location of joint and tendon inflammation.”
“Coupling [clinical examination] with [ultrasound] aids to identify correctly the inflamed sites in the ankle region, which enhances significantly the quality of the clinical assessment and may increase the effectiveness of local injection therapy,” they added. “Training on [ultrasound] of practitioners who are involved in the care of children with JIA is recommended to increase the skills in the evaluation of ankle disease.” – by Jason Laday
Disclosures: The researchers report no relevant financial disclosures.