Frozen shoulder after COVID-19 vaccination

BACKGROUND: The data on frozen shoulder and shoulder injury related to vaccine administration (SIRVA) after coronavirus disease 2019 (COVID-19) vaccination are absent from the literature. Hence, the purpose of this case series was to describe the clinical presentation and short-term follow-up of patients who developed frozen shoulder after COVID-19 vaccination. METHODS: In the present study, 10 patients (9 women and 1 man) with a mean age of 53 ± 8 years (range, 43-68 years) who presented to the shoulder surgeon’s practice center with painful stiffness of the shoulder after COVID-19 vaccination between June 1 and September 30, 2021, were retrospectively evaluated. RESULTS: All 10 patients had normal radiographs and were diagnosed as frozen shoulder. Eight patients (80%) had a comorbidity during presentation (4 patients with hypothyroidism, 3 patients with diabetes mellitus, and 1 patient with prediabetes/hyperglycemia). Symptoms developed immediately after the vaccination in 6 patients (60%), at 48 hours in 1 patient (10%), and at 10 days in 3 patients (30%). The mean pain visual analog scale score was 6.5 ± 1.9 (range, 2.5-8), and both active and passive range of motion were limited in all the patients at the time of presentation. CONCLUSION: The musculoskeletal specialists who will see such patients with painful shoulder stiffness should be aware of the frozen shoulder diagnosis, which can occur after COVID-19 vaccination, so that such patients can be identified and treated early.