Frozen shoulder
Frozen shoulder is a painful condition that leads to increasing stiffness and restricted movement in the shoulder. It often develops after periods of immobility or due to underlying health conditions and can take a long time to improve. The condition occurs when the tissue inside the shoulder joint thickens and tightens, forming internal scar-like adhesions. This process triggers inflammation and the development of new blood vessels and nerves, which can contribute to pain and stiffness.
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Diagnosis primarily relies on physical examination but can be difficult depending on the stage of the condition or if other shoulder issues are present. Treatment includes physiotherapy, steroid injections, anti-inflammatory medications, hydro dilatation, and surgical options, though their effectiveness remains uncertain. Advancing research aims to develop new therapies to improve outcomes for individuals with this condition.
Symptoms and Stages of Frozen Shoulder
Frozen shoulder (FS) is a common condition that leads to progressive shoulder pain and a significant reduction in the range of motion of the glenohumeral joint. Although the exact cause remains unknown, FS is understood as a process involving initial synovial inflammation, followed by capsular fibrosis. The condition often resolves over time, but the duration and severity vary among individuals.
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FS is generally classified into three phases:
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Freezing Phase – A gradual onset of shoulder pain with increasing stiffness and loss of motion.
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Frozen Phase – Pain begins to subside, but stiffness remains, with both active and passive range of motion equally restricted.
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Thawing Phase – Gradual improvement in movement and reduction of symptoms.
FS can be classified as:
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Primary (Idiopathic) FS – Occurs without any known cause or underlying condition. It is commonly associated with systemic illnesses, such as diabetes (10%–36% of cases), thyroid disorders, adrenal disease, cardiopulmonary conditions, and hyperlipidemia.
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Secondary FS – Develops due to an identifiable cause, such as trauma (fractures, dislocations, soft tissue injuries) or non-traumatic shoulder conditions (osteoarthritis, rotator cuff tendinopathy, calcific tendinitis).
Risk Factors
Numerous studies have demonstrated the association between frozen shoulder (FS) and various medical conditions such as diabetes, hyperlipidemia, thyroid disease, Dupuytren contracture, cardiovascular disease, and cervical spondylosis. However, the practical applicability of these findings in clinical settings remains limited. A multivariate binary logistic regression analysis revealed that low BMI, cervical spondylosis, type 2 diabetes, and hyperlipidemia were identified as independent risk factors for FS. These factors were incorporated into a diagnostic prediction model, which led to the development of simplified equations. The findings suggest that the combined index of BMI, cervical spondylosis, type 2 diabetes, and hyperlipidemia exhibits favorable predictive capability for the occurrence of FS. Consequently, this combined index holds promise as a valuable tool for early clinical diagnosis of FS.
Menopause is a significant risk factor for frozen shoulder (FS) in women due to the drop in estrogen levels. Estrogen helps maintain joint and connective tissue health, and its reduction during menopause can increase the likelihood of inflammation and fibrosis in the shoulder joint. Women in peri-menopausal and post-menopausal stages are more prone to developing FS, partly due to the higher prevalence of associated conditions like diabetes and thyroid disorders, which also elevate FS risk. As such, menopause should be considered when assessing FS risk in women.
Conservative Treatment for Frozen Shoulder
Frozen shoulder (FS) can often be managed effectively with conservative treatments, which are successful in up to 90% of cases. The key to treatment is understanding the phase of FS, as symptoms and approaches differ across the freezing (10–36 weeks), frozen (4–12 months), and thawing (12–42 months) phases.
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Medication
Pain relief is the priority in the freezing stage. While NSAIDs are commonly used, they do not alter the course of FS. Oral corticosteroids can provide early pain relief and improved function, but their long-term benefits remain uncertain. Calcitonin, a polypeptide hormone, has shown promise in reducing pain and inflammation, but more research is needed.
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Hydrodilatation (HD)
Hydrodilatation (HD) involves injecting a mixture of saline, steroid, and anesthetic into the joint to stretch the capsule. This technique is effective in improving pain, range of motion (ROM), and function, particularly in the short term. In Australia, HD is considered a standard treatment option for frozen shoulder, typically offered to patients who do not respond to conservative measures such as physiotherapy or corticosteroid injections. Following HD, patients usually undergo physiotherapy to further improve shoulder mobility and function. Physiotherapy plays a crucial role in maximizing the benefits of the procedure by focusing on gentle stretching exercises and strengthening to enhance recovery. However, more research is needed to determine whether capsular rupture is necessary for maximum benefit.
Corticosteroid Injections
Steroid injections provide short-term pain relief, particularly in the early stages. Research suggests they are more effective than oral steroids in improving ROM and function. While the injection site (glenohumeral vs. subacromial) remains debated, most studies agree that injections combined with physiotherapy yield better results than either treatment alone.
Physiotherapy
Physiotherapy is a cornerstone of FS treatment, focusing on restoring range of motion (ROM) and reducing stiffness. An exercise program should include gentle stretching (e.g., forward elevation, internal/external rotation) performed multiple times daily. Studies show that physiotherapy, particularly when combined with other treatments, leads to better mobility, reduced anxiety, and overall improved recovery.
References
Liu, X., et al., 'Risk Factors for Frozen Shoulder: A Multivariate Binary Logistic Regression Analysis', PubMed Central, https://pmc.ncbi.nlm.nih.gov/articles/PMC11220144/, 2020.
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PubMed (2022). "Frozen Shoulder: Current Concepts and Treatment Approaches." Available at: https://pubmed.ncbi.nlm.nih.gov/36075904/
