Prevalence and associated risk factors of frozen shoulder in patients with shoulder musculoskeletal disorders: a cross-sectional analysis

Abstract Introduction Frozen shoulder (FS) is a disabling musculoskeletal condition characterised by persistent pain and progressive restriction of shoulder mobility. It is frequently associated with underlying shoulder disorders such as rotator cuff injuries and impingement syndrome. Material and methods This cross-sectional study included 76 patients, who were categorised into two groups: those diagnosed with rotator cuff injury ( n = 44) and those with shoulder impingement syndrome ( n = 32). Differences in FS prevalence between these groups were assessed using the chi-square test (Hypothesis 1). Binary logistic regression was applied to evaluate the influence of age, gender, diabetes mellitus and history of shoulder trauma on FS development (Hypothesis 2). Pearson correlation analysis was used to examine the relationship between pain severity and movement limitations (Hypothesis 3). Results The prevalence of FS was present in 71 of 76 patients (93.4%); prevalence was 95.5% among patients with rotator cuff injury and 90.6% among those with impingement syndrome, with no significant difference between the groups ( p = 0.402). Logistic regression analysis identified age ( p < 0.001), gender ( p = 0.024), and history of shoulder trauma ( p < 0.001) as significant factors associated with frozen shoulder, whereas diabetes mellitus was not significant based on the Firth penalized logistic regression model ( p = 0.412); the standard maximum-likelihood estimate for this predictor ( p = 0.998) was unstable due to sparse-data bias and was not used for interpretation (table 4).. A strong positive correlation was observed between pain severity and movement limitations ( r = 0.685, p < 0.001). Conclusions FS demonstrates a consistently high prevalence among patients with different shoulder musculoskeletal disorders, and may reflect shared pathophysiological pathways, though this cannot be confirmed by a cross-sectional design. Key determinants include age, gender and prior shoulder trauma, while diabetes was not a significant predictor in this cohort.