Ultrasound imaging for the rheumatologist XLV. Ultrasound of the shoulder in psoriatic arthritis

OBJECTIVES: The aims of this study were to investigate the prevalence of ultrasound (US) pathologic abnormalities in the shoulders of psoriatic arthritis (PsA) patients and to compare them with the main clinical findings. METHODS: Ninety-seven PsA patients were enrolled in the study. The subacromial/subdeltoid bursa, the sheath of the long biceps tendon, the glenohumeral joint and the acromion-clavicular joint were examined for the presence of synovial effusions and synovial hypertrophy. Rotator cuff tendons (supraspinatus, subscapularis, infraspinatus) were imaged for tendinosis, calcifications and total or partial tears, while deltoid enthesis were evaluated for local enthesitis and the lesser and greater tuberosity of the humerus for the presence of enthesophytes. RESULTS: Tendinosis represented the most frequent abnormal finding. Supraspinatus tendinosis was detected more often than subscapularis and infraspinatus tendinosis. When considering tendon tear, supraspinatus was also the most frequently involved anatomical structure. Clinical examination frequently failed to detect abnormalities in patients in whom US examination showed pathological findings. This is particularly true for tendon involvement, i.e. effusion within the sheath of the biceps tendon was imaged in 43 shoulders but clinical assessment reported abnormalities only in 22 shoulders (p<0.0001). CONCLUSIONS: US examination appears to be a useful and sensitive imaging technique, specifically in identifying joint and tendon involvement of the shoulder.