Covid-19 associated shoulder girdle calcific myositis: a novel entity

Objective: To investigate the prevalence, describe the radiological features, and consider the clinical sequelae of COVID-19-associated shoulder girdle calcific myositis. Methods: All patients who underwent a CT pulmonary angiogram study at our institution (Queen Alexandra Hospital, Portsmouth Hospitals University NHS Trust, Portsmouth, United Kingdom) in April and May 2020, January 2021, and July 2021 were included. A total of 1239 CT pulmonary angiogram studies for 1201 patients were reviewed. Patients with COVID-19 and associated shoulder girdle calcific myositis were identified. Their electronic patient records were reviewed. The patients' demographics, serum inflammatory markers, and proning history were recorded. Results: Of the 364 patients in Wave 1, 71 patients (19.5%) had COVID-19, and of those, 2 patients (2.8%) had shoulder girdle calcific myositis. Of the 521 patients in Wave 2, 354 patients (67.9%) had COVID-19, and of those, 3 patients (0.8%) had shoulder girdle calcific myositis. Of the 316 patients in Wave 3, 37 patients (11.7%) had COVID-19, and of those, 1 patient (2.7%) had shoulder girdle calcific myositis. The overall prevalence was 1.3%. The most common site of calcific myositis was within the subscapularis muscle. Conclusion: COVID-19-associated shoulder girdle calcific myositis is a rare extrapulmonary musculoskeletal manifestation of COVID-19. Early recognition and increased awareness of this disease entity, in our experience, aids in reducing patient morbidity and improving long-term functional outcome. Advances in knowledge: We have reported a novel disease entity associated with COVID-19, in the form of shoulder girdle calcific myositis. We have described the common imaging features and discussed our experience of management and clinical sequelae.