Adhesive Capsulitis

Adhesive capsulitis affects an estimated 2% to 5% of the population, with incidence rising due to ageing and sedentary lifestyles. Adhesive capsulitis most commonly affects middle-aged women, particularly those aged 50 to 70 years. Chronic low-grade inflammation is considered important in the progression of adhesive capsulitis. Hyperglycaemia alters the collagen matrix of the shoulder joint capsule, contributing to fibrosis and inflammatory changes typical of adhesive capsulitis. Metabolic disorders, especially diabetes and thyroid disease, increase the risk of developing adhesive capsulitis. Some patients with adhesive capsulitis experience recurrent pain as long as six years after onset, and a subset develops permanent symptoms. Diagnosis requires range-of-motion restriction greater than 25% in at least two planes, with passive external rotation loss greater than 50% compared with the unaffected shoulder, or external rotation less than 30 degrees.