Background The rotator cuff consists of muscles and their tendons: subscapularis, supraspinatus, infraspinatus. The subscapularis tendon inserts in the lesser tuberosity of the humerus. The supraspinatus tendon inserts in the of the humerus. The infraspinatus tendon inserts in the posterior portion of the greater tuberosity, touching the posterior aspect of the supraspinatus tendon. Enthesitis is an inflammatory lesion of the tendon, ligament and capsular insertions into the bone. Sonography is the method of choice for studying periarticular soft tissues because it is capable of detecting both the early (oedema, thickening) and late alterations (erosions and enthesophytes).

Objectives To compare ultrasonography with clinical examination in the detection of abnormality of tendon insertion in patients with osteoarthritis.

Methods 60 patients with osteoarthritis underwent clinical and ultrasonographic examination of the following bilateral entheseal sites: anterior portion of the greater tuberosity, the posterior portion of the greater tuberosity and lesser tuberosity of the humerus. Clinical enthesitis was defined by the presence of at least one of the following findings: spontaneous pain, tenderness elicited by pressure, and local swelling of the enthesis. Ultrasound investigaton was performed to detect structure thickness, bony erosion, and enthesophyte (bony spur).

Results Insertion abnormality detected in 58% of total count of enteses, 12% not have clinical features and detected with ultrasound investigation only. Determined a significant correlation between tenderness of tuberosities of humerus and the presence of ultrasound features. There was no significant correlation between spontaneous pain and enthesitis. No significant correlation between local swelling of the enthesis and ultrasound features was noted.

Conclusions Enthesistis of rotator cuff is frequent manifestation in osteoarthritis. Ultrasound investigation exceeds clinical examination in the detection of enthesitis of the shoulder. Tenderness of tuberosities of humerus is accurate sign of enthesitis of the shoulder.

Disclosure of Interest None Declared