Background US scan was shown to be effective and useful for investigation of gleno-humeral joint (GHJ) synovitis by posterior and axilar (inferior) access (1,2). Synovial fluid in the subacromial bursa and biceps tendon is also associated with GHJ inflammation (3). Anterior access for GHJ assessment has not been investigated. Rotator interval (RI) is the intra-articular triangular space in the upper anterior part of the biceps bed between supraspinatus (SST) and subscapularis (SSC) tendons. The RI is covered with the GHJ capsule and reflects articular processes.
Objectives To measure GHJ parameters and rotator interval from anterior access and to compare to data from posterior and inferior access.
Methods Twenty healthy controls (M:F=15:5, age of 45.1±11.2) and 16 patients (M:F=5:11, age of 54.6±14.7) with active rheumatoid arthritis (RA) (DAS28 4.6±1.2) were investigated (Sonosite-Titan, linear 5-10 MHz probe 9L38). In order to make GHJ visible on anterior access we used the original GHJ opening maneuver: supine body position, the adducted to the body elbow and flexed 90 degree on the bed, maximal external shoulder rotation (forearm on the bed). Three structural points are essential for anterior GHJ visualization: 1.A round hyperecoic humeral head; 2. GHJ anecoic cartilage +/- fluid (synovitis); 3. subcscapular tendon situated forward to the GHJ cartilage. The GHJ width was measured for every transducer position at two points. The positions were as follow: posterior transversal, inferior longitudinal, anterior longitudinal along the articular line, anterior transfersal upper, middle and lower. The joint width included thickness of cartilage + synovial fluid/pannus. RI width (SST - SSC) and height (upper biceps channel) were measured.
Results See Table 1.
Our normal GHJ values by posterior and inferior access were within previously estimated range (posterior GHJ width <2.0mm, inferior <3.0mm) (1,2). We acquired the first values of GHJ width from anterior access. The last were within a range of <1.5-1.7mm for healthy controls. Patients with RA showed significantly enlarged joint cavity in posterior, inferior and anterior access. RI was not inflamed. Posterior and inferior data of GHJ width correlated significantly (p=0.01). The data did not correlate with anterior values (p=0.44, 0.56). Synovitis was much more prominent in posterior, upper anterior transversal and anterior longitudinal transducer positions.
Conclusions The GHJ may be visualized by anterior access using a special maneuver. Synovitis in the anterior region of GHJ may develop at an independent rate. Anterior GHJ sonography may be complimentary to the classic access.
Van Holsbeeck MT, et al. Musculoskeletal ultrasound. Mosby, St. Luis. 1991.
Koski JM. Scand J Rheumatol 1991;20:49-51.
Ptasznik R. Sonography of the shoulder. 2001.
Disclosure of Interest None declared