Can Secondary Adhesive Capsulitis Complicate Calcific Tendinitis of the Rotator Cuff? An Ultrasound Imaging Analysis

Background: Adhesive capsulitis (AC) of the glenohumeral joint is a recognized cause of pain associated with both active and passive restricted ranges of movement. AC can be subdivided into primary and secondary forms. Trauma, surgery, immobilization, and diabetes mellitus are the leading well-recognized causes of secondary AC. Calcific tendinitis/tendinitis (CT) of the rotator cuff is considered a possible trigger for AC, as reported in a few previous articles. However, there are no original investigations that assess the frequency and characteristics of this association. The aim of our research was to evaluate the presence of AC in a cohort of patients with a known CT condition of the rotator cuff by an ultrasound (US) examination.

Materials and methods: We prospectively enrolled all the patients admitted at our single institution (October 2022-June 2023) for the preoperative US evaluation of a known CT condition. In these patients, we searched for parameters related to secondary AC. An axillary pouch (AP) thickness equal to or greater than 4 mm (or greater than 60% of the contralateral AP) was considered diagnostic of AC. Moreover, rotator interval (RI) thickness and the presence of effusion within the long-head biceps tendon (LHBT) sheath was also assessed in all patients.

Results: A total of 78 patients (54F, 24M-mean age = 50.0 and range = 31-71 y.o.) were enrolled in the study. In 26 of those patients (26/78-33.3%), US signs of AC were detected. Notably, the mean AP thickness in patients with AC and CT was 3.96 ± 1.37 mm (Group 1) and 2.08 ± 0.40 mm in patients with CT only (Group 2). RI thickness was significantly greater in patients with superimposed AC: 2.54 ± 0.38 mm in Group 1 and 1.81 ± 0.41 mm in Group 2 (p < 0.00001). Moreover, effusion within the LHBT was significantly more frequently detected in patients with AC: 84.61% in Group 1 versus 15.79% in Group 2-p < 0.00001.

Conclusion: US signs of AC are found in one-third of patients with CT of the rotator cuff, demonstrating that AC represents a frequent complication that should be routinely evaluated during US investigation to provide more personalized treatment strategies.