Ultrasound imaging for the rheumatologist XLIV. Ultrasound of the shoulder in healthy individuals

OBJECTIVES: To investigate the prevalence of shoulder ultrasound (US) detectable abnormalities in asymptomatic individuals of various ages and to correlate the US findings with clinical data. METHODS: 97 healthy subjects were enrolled in the present study. They were subgrouped according to their age, as follows: group I (20-29 years); group II (30-39 years); group III (40-49 years); group IV (50-59 years); group V (>60 years). A physical examination of both shoulders, based on a series of provocative maneuvers, was carried out. The US assessment was performed by using a Logiq9 machine equipped with a multi-frequency linear probe working at 12MHz and included the study of a number of structures for the evaluation of local abnormalities, as follows: the long head of biceps tendon (synovial effusion (SE), synovial hypertrophy (SH), power Doppler (PD) signal); the subacromion-subdeltoid and sub-scapularis bursae (SE, SH, PD signal); the rotator cuff tendons (tendinosis, calcifications, tears, impingement); the acromionclavicular (ACJ) and gleno-humeral joints (SE, SH, PD signal, osteophytes, erosions, fibrocartilage calcifications, cartilage abnormalities, tophaceous deposits). In addition, deltoid, throchite and throchine enthesopathy were searched for. RESULTS: 194 shoulders were studied in total. A low but variable percentage of joints of healthy individuals (3.1-13.4%) showed positive provocative maneuvers. 138 shoulders (71.1%) did not show any US abnormalities. The most frequent changes were SE of ACJ (25.5%), osteophytes of ACJ (23.3%), and supraspinatus tendinosis (20.6%). The prevalence of abnormalities progressively increased with age. Sub-clinical involvement was present in most cases, being provocative maneuvers positive only in a low percentage of joints. CONCLUSIONS: The present study demonstrated the presence of a wide set of US-detectable changes in healthy subjects, that were more frequently present in elderly individuals. The absence of any clinical sign of local pathology cannot exclude the presence of local abnormalities.