Incidence of adhesive capsulitis of the shoulder during the beginning of the COVID-19 pandemic

OBJECTIVE: Adhesive capsulitis is an inflammatory disease of the joint capsule, clinically manifested as pain, stiffness, and dysfunction of the shoulder. We subjectively observed an increased incidence of adhesive capsulitis, and raised the hypothesis that adhesive capsulitis was more frequent in magnetic resonance imaging examinations performed during the COVID-19 pandemic as compared with examinations prior to this period. METHODS: Data from medical records and magnetic resonance imaging of the shoulder presenting typical imaging findings of adhesive capsulitis, performed in our organization from March to June 2020, were evaluated and compared with data and imaging from the same period of the previous year. To this end, an organizational business intelligence tool called "search reports" was used, searching for the term "adhesive capsulitis" in the radiological report, results were tabulated, and corresponding magnetic resonance imaging exams were analyzed. RESULTS: Our search found a total of 240 and 1,373 cases of adhesive capsulitis in the 2020 and 2019 periods, respectively. The mean age of patients was 53.9 years in the 2020 group and 49.9 years in 2019 (p<0.001). Magnetic resonance imaging findings were positive for adhesive capsulitis in 40 out of 240 shoulders (16.7%) in the 2020 group versus 127 out of 1,373 shoulders (9.2%) in the 2019 group. This difference was statistically significant (p=0.001). CONCLUSION: Our study findings suggest a relative increase in the proportion of magnetic resonance imaging findings suggestive of adhesive capsulitis cases during COVID-19 pandemics based on data from our organization.