A comprehensive MRI-based study on adhesive capsulitis and its correlations with tendinosis and systemic diseases

The association between adhesive capsulitis and hypothyroidism is well-known. However, its relationship with hypertension and diabetes remains debated. While, rotator cuff (RC) tendinosis is frequently observed, to our knowledge, there is no study indicating its link to adhesive capsulitis. This study aimed to assess the prevalence RC tendinosis in adhesive capsulitis and examine associations between adhesive capsulitis and hypertension, diabetes, thyroid dysfunction, and inferior glenohumeral ligament (IGHL) thickness.

This retrospective study included 503 patients with adhesive capsulitis who underwent magnetic resonance imaging (MRI) of the shoulder. Patients with previous shoulder trauma, surgery, or rheumatologic disease were excluded. Clinical data on hypertension, diabetes, and thyroid dysfunction were collected. The IGHL thickness was measured, and RC tendinosis was classified according to tendon involvement. Statistical analyses included t tests, chi-square tests, logistic regression, and receiver operating characteristic analysis.

Rotator cuff tendinosis was observed in 76.94% of patients, with supraspinatus tendinosis being the most common (74.95%). Thyroid dysfunction was significantly more prevalent in patients with adhesive capsulitis (15.90%, p < 0.001), while hypertension was lower (21.87%, p < 0.001) compared to the general population. The prevalence of diabetes (12.52%) was not significantly different from the general population (p = 0.426). Diabetes was associated with increased IGHL thickness (p = 0.005), whereas thyroid dysfunction was linked to lower IGHL thickness (p = 0.023). The IGHL thickness did not predict tendinosis (AUC = 0.47).

Supraspinatus tendinosis is overrepresented in patients with adhesive capsulitis, with a prevalence of 75%. Thyroid dysfunction may contribute to its pathogenesis as indicated in previous research. Additionally, IGHL thickness alone is not a reliable predictor of tendinosis. Further studies are needed to explore these associations.