Frozen shoulder

• first introduced by Codman in 1934, the term "frozen shoulder" describes a glenohumeral disorder characterized by shoulder pain, limitations in active and passive elevation, and restricted external rotation (1)
• the condition is also known as adhesive capsulitis
• commonly affects people in their 50s (typically aged 40 to 60 years) and is more prevalent in women (5)

Pathophysiology and Presentation

• thought to result from progressive fibrosis and thickening of the joint capsule and adherence to the humeral head
• can occur in one shoulder or both shoulders simultaneously, with the non-dominant shoulder being slightly more likely to be affected (2)
• course is typically self-limiting, with recovery taking between 12 and 42 months (3); nearly all patients improve, but normal range of movement may not fully return, and 15% experience long-term disability (2, 3)

Aetiology and Risk Factors

• primary (idiopathic) or secondary to another underlying clinical condition
• diabetes mellitus is the most common association, carrying a lifetime risk of 10% to 20% for developing frozen shoulder (1)
• diabetic patients face a higher risk of bilateral symptoms and prolonged recovery, often with residual functional impairment (4)

Management and Comparative Efficacy

• primary care and conservative management: physiotherapy is widely used and often combined with intra-articular corticosteroid injections (4)
• secondary care interventions: includes hydrodilatation, arthroscopic capsular release, and manipulation under anaesthesia (MUA) (4)
• UK FROST trial findings: pragmatic comparison of MUA, arthroscopic capsular release, and early structured physiotherapy with intra-articular corticosteroid injections showed no clinical superiority among options (4)
• 2026 network meta-analysis evidence: moderate-certainty evidence indicates extracorporeal shockwave therapy (ESWT) reduces short-term pain compared to usual care, while MUA (with or without intra-articular steroids) improves short-term shoulder flexion (5)
• long-term and safety uncertainties: comparative evidence for interventions past 3 months, functional improvement, and relative adverse event profiles remains of low or very low certainty across published trials (5)
• mid-term efficacy (3 to 6 months): evidence past 3 months is sparse and imprecise; low-certainty evidence suggests potential mid-term functional gains with ESWT and flexion gains with passive mobilisation, but long-term sustained recovery remains unproven (5)

Reference:

1. Uppal HS, Evans JP, Smith C. Frozen shoulder: A systematic review of therapeutic options. World J Orthop. 2015;6(2):263-268.
2. Dias R et al. Frozen shoulder. BMJ. 2005;331(7530):1453-1456.
3. van de Laar SM, van der Zwaal P. Management of frozen shoulder. Orthop Res Rev. 2014;6:81-90.
4. Karbowiak M, Holme T, Mirza M, Siddiqui N. Frozen shoulder. BMJ. 2022;377:e068547.
5. Meng J et al. Interventions for adhesive capsulitis: systematic review and network meta-analysis of randomised controlled trials. BMJ. 2026;395:e101057.