Ultrasound learning curve in gout: a disease-oriented training program

To describe the learning curve of rheumatologists with limited experience using ultrasound (US) attending an intensive disease-oriented training program focusing on the skills required to obtain and interpret US signs of monosodium urate (MSU) crystal deposits in joint and periarticular tissues.

Three investigators participated in a 7-day training program involving 12 men with gout. The agreement between the expert and beginners was calculated in 4 sessions involving 8 patients with gout. The US assessment was performed at the second and third metacarpophalangeal joints, knee, tibiotalar and first metatarsophalangeal joints, second and third finger flexors, quadriceps and patellar posterior tibialis, peroneus longus and brevis, and Achilles tendons. The presence or absence of synovial fluid/synovial hypertrophy, double contour sign, intra- or periarticular and intratendinous tophi, bursitis, bone erosions, and tendon tears was recorded.

A total of 416 anatomic sites were studied. Kappa values and overall agreement percentages of qualitative assessments of US gout findings at the end of the exercise both showed moderate to excellent agreement, while in the first session they showed poor/fair agreement. At the end of the training session, sensitivity, specificity, and capability of the beginners were also improved.

After 1 week of the disease-oriented training program, rheumatologists with limited experience in US were satisfactorily able to detect and interpret the main US signs indicative of MSU crystal deposits at different tissues in patients with gout.