What is frozen shoulder (adhesive capsulitis)?

Frozen Shoulder (Adhesive Capsulitis)

Frozen shoulder, or adhesive capsulitis, is a condition characterized by stiffness and pain in the shoulder joint with significant limitation in both active and passive range of motion, particularly in external rotation and abduction.

Definition and Clinical Presentation

• Frozen shoulder is characterized by painful and limited active and passive range of motion in the shoulder joint 1
• The condition typically presents with stiffness and pain that significantly restricts shoulder movement and strength 2
• Adhesive capsulitis progresses through three distinct phases: freezing (painful), frozen (adhesive), and thawing 3

Pathophysiology

• While the exact etiology remains unclear, frozen shoulder involves inflammation of the joint capsule followed by fibrosis and contracture 1
• The condition leads to thickening of the coracohumeral ligament, which can be detected on MRI with high specificity 4
• Adhesive capsulitis results in decreased joint volume and restricted glenohumeral movement 2

Classification

• Primary frozen shoulder (idiopathic adhesive capsulitis) is not associated with systemic conditions or history of injury 1
• Secondary frozen shoulder can be categorized into three types 1:
  • Systemic (associated with conditions like diabetes mellitus or hypothyroidism)
  • Extrinsic (resulting from factors outside the shoulder)
  • Intrinsic (resulting from rotator cuff pathology)
• Another useful classification is based on irritability levels (low, moderate, high), which helps guide treatment decisions 1

Diagnosis

• Diagnosis is primarily clinical, based on patient history and physical examination findings 5
• Key diagnostic features include pain and tenderness of the shoulder joint with limited range of motion, especially in external rotation 4
• Imaging is not necessary for diagnosis but can help rule out other conditions 4
• MRI finding of coracohumeral ligament thickening is highly specific for adhesive capsulitis 4

Treatment Options

Non-pharmacological Management

• Physical therapy with stretching exercises and joint mobilization is a cornerstone of treatment 1, 3
• Treatment should progress as the patient's pain and irritability decrease 1
• Active, active-assisted, or passive range of motion exercises should be used to prevent progression 5
• Local application of heat before exercise can provide symptomatic relief 5
• Exercises should focus on increasing external rotation and abduction to restore shoulder mobility 5, 6

Pharmacological Management

• First-line medications include acetaminophen or NSAIDs for pain relief 5, 4
• Topical NSAIDs should be considered as first pharmacological treatment for mild to moderate pain 5
• Oral corticosteroids (short-term) may be used to reduce inflammation and pain 4
• Intra-articular corticosteroid injections have strong evidence for significant short-term benefit (4-6 weeks) compared to other treatments 1
• For shoulder pain related to spasticity, botulinum toxin injections into specific muscles may be beneficial 5

Advanced Interventions

• Glenohumeral hydrodistension (joint distension with fluid) combined with physical therapy has shown success in improving range of motion and reducing pain, especially when performed in early stages 7
• Patients with persistent symptoms despite conservative treatment for 6-12 weeks may be candidates for surgical interventions 4:
  • Manipulation under anesthesia
  • Arthroscopic capsular release

Prognosis

• Traditionally, frozen shoulder was thought to be self-limiting with full resolution within 1-2 years 4
• However, recent evidence suggests that without treatment, patients may experience persistent functional limitations 4
• Early diagnosis and treatment lead to better outcomes, with earlier recovery of range of motion 7
• Shoulder pain can significantly delay rehabilitation and functional recovery, affecting quality of life 6, 5

Special Considerations

• Frozen shoulder has increased prevalence in patients with diabetes mellitus and hypothyroidism 4
• Avoid using overhead pulleys in treatment as they encourage uncontrolled abduction and may worsen symptoms 6, 5
• Protecting the affected limb from trauma is important to prevent complications 5
• The condition can contribute to depression, sleeplessness, and reduced quality of life if not properly managed 5