CT arthrography of adhesive capsulitis of the shoulder: Are MR signs applicable?

Abstract

Objective: To determine if diagnostic signs of adhesive capsulitis (AC) of the shoulder at Magnetic Resonance Imaging (MRI) and arthrography (MRA) are applicable to CT arthrography (CTA).

Methods: 22 shoulder CTAs with AC were retrospectively reviewed for features described in MR literature. The control group was composed of 83 shoulder CTA divided into four subgroups 1) normal (N = 20), 2) omarthrosis (N = 19), 3) labral injury (N = 23), and 4) rotator cuff tear (N = 21). Two musculoskeletal radiologists assessed the rotator interval (RI) for obliteration, increased width and thickening of coracohumeral ligament (CHL). The width and capsule thickness of the axillary recess were measured.

Results: The width of the axillary recess was significantly decreased in the AC group (4.6 ± 2.6 mm versus 9.9 ± 4.6 mm, p ≤ 0.0001; sensitivity and specificity of 84% and 80%). Thickness of the medial and lateral walls of the axillary capsule was significantly increased in the AC group (5.9 ± 1.3 mm versus 3.7 ± 1.1 mm, p ≤ 0.0001 and 5.7 ± 1 mm versus 3.5 ± 1.3 mm, p ≤ 0.0001, respectively). CHL thickness was significantly increased in the AC group (4.1 ± 1 mm (p ≤ 0.001)) in comparison to others groups. Obliteration of the RI was statistically significantly more frequent in patients with AC (72.7% (16/22) vs. 12% (10/83), p < 0.0001). Width of the RI did not differ significantly between patients and controls (p ≥ 0.428).

Conclusion: Decreased axillary width, and thickened axillary capsule are MR signs of AC applicable to CTA. Evaluation of rotator interval seems useful and reproducible only for obliteration.

Keywords: Adhesive capsulitis; Arthrography; CTA; Frozen shoulder; MRA; Rotator interval.

Fig. 1

a and b. Axial view of the glenohumeral joint with demonstration of the coronal oblique (a) and sagittal oblique (b) planes at the level of the coronoid process tip.

Fig. 2

55-year-old patient addressed for suspicion of cuff rupture, with a normal CT arthrography. Sagittal oblique reconstruction at the level of the coracoid tip (c). The rotator interval (*) is free with the coracohumeral ligament lying over (white arrow). * = rotator interval; c = coracoid tip; SSp = supraspinatus muscle; SSc = subscapularis muscle.

Fig. 3

CTA coronal oblique reconstruction of a 62-year-old patient with adhesive capsulitis reveals the subchondral bone resorption of the humeral head (long white arrow→), the thickened capsule (empty arrow〉) and synovium (short white arrow→), and the narrow axillary recess (double black arrows). ↔ axillary pouch width; white arrow = medial wall of the axillary pouch, black empty arrow = lateral wall of the axillary pouch.