Effect Of Covid 19 Disease Severity On Incidence Of Adhesive Capsulitis Of The Shoulder

Adhesive Capsulitis is a chronic fibrosing condition of the of the shoulder capsule involving fibroblasts and myofibroblasts which lay down a dense matrix of type-I and type-III collagen within the capsule. Systemic manifestations of COVID-19 evolve from an increased inflammatory response that results from both the effects of SARS-CoV-2 on infected target cells and the host’s immune response. Adhesive capsulitis and COVID 19 infection share a common pathophysiology of an overexpression of inflammatory cytokines, yet there are minimal studies addressing the relationship between the two conditions. PURPOSE: To determine if there is a higher prevalence of adhesive capsulitis of the shoulder in patients with increased severity of COVID-19 disease requiring hospitalization compared to non-hospitalized cases. METHODS: This is a retrospective cohort study of members of the Kaiser Foundation Health Plan in Southern California. Data was obtained during the pre-COVID vaccination period from January 2020 to December 2020 for comparison between hospitalized vs non hospitalized COVID 19 patients and the development of adhesive capsulitis of the shoulder. The patients diagnosed with adhesive capsulitis of the shoulder, was obtained 2 months to 1 year after the diagnosis of COVID 19. The study variables were reported as categorical variables and compared using chi-square test of Fisher’s exact test. Logistic regression was then used to explore the relationship between the main study variables. RESULTS: The odds ratio for the risk of adhesive capsulitis in patients hospitalized for COVID or pneumonia (hospitalization with COVID or pneumonia diagnosis codes as principal diagnosis for inpatient encounters within 30 days on or after COVID index date) was OR (95% CI) 0.97 (0.69-1.37, p = 0.87). There was no statistically significant difference between patients with increased severity of COVID-19 disease requiring hospitalization compared to non-hospitalized cases. CONCLUSION: Increased severity of COVID 19 disease requiring hospitalization is not a risk factor for development of adhesive capsulitis of the shoulder.