What is the diagnosis and treatment approach for a patient over 40 with shoulder pain and stiffness, possibly with a history of trauma, diabetes, or other inflammatory conditions?

Diagnosis of Adhesive Capsulitis

Adhesive capsulitis is diagnosed clinically based on the characteristic finding of equal restriction of both active and passive shoulder range of motion in all planes, particularly external rotation, which is the most significantly affected motion. 1, 2

Clinical Diagnostic Criteria

The diagnosis is primarily clinical and does not require imaging for confirmation 3, 2:

• Key diagnostic feature: Equal restriction of both active AND passive range of motion in all planes, especially external (lateral) rotation 1, 2
• External rotation is the most significantly affected motion and relates strongly to the onset of shoulder pain 1
• Abduction is severely restricted, particularly in the frozen stage 1
• Gradual onset of shoulder pain with progressive limitation of movements 4

Essential Differential Diagnoses to Exclude

The American College of Rheumatology emphasizes that several conditions can mimic adhesive capsulitis and must be ruled out 1:

• Degenerative joint disease/osteoarthritis
• Soft tissue rheumatic disorders
• Crystal arthropathies
• Septic arthritis
• Rotator cuff tendinopathy or tear
• Biceps tendinopathy
• Subacromial/subdeltoid bursitis
• Acromioclavicular arthropathy
• Autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis)
• Neoplasm 3, 5

The distinguishing feature is that adhesive capsulitis shows equal restriction of active and passive motion, whereas rotator cuff pathology typically shows preserved passive motion with limited active motion. 1

Role of Imaging

Plain Radiographs

Plain X-rays are usually normal in adhesive capsulitis because the pathology involves capsular fibrosis and inflammation, not bony changes. 6

• Radiographs are primarily useful to exclude other causes such as fractures, dislocations, glenohumeral arthritis, or rotator cuff arthropathy 6
• Standard shoulder series will demonstrate normal bony anatomy and alignment 6

Advanced Imaging (When Needed)

Advanced imaging is not necessary to make the diagnosis but may be considered when the diagnosis is uncertain 2:

• MRI without contrast: Coracohumeral ligament thickening yields high specificity for adhesive capsulitis 2
• Bone scintigraphy: Shows increased periarticular activity in adhesive capsulitis, but this finding is nonspecific and can also occur with fractures and rotator cuff tears 7, 1, 8, 6
• Bone scintigraphy is rarely used clinically due to poor specificity 6

Risk Factors to Identify

Primary Risk Factors

• Diabetes mellitus: Adhesive capsulitis affects approximately 14-20% of diabetic patients, with poor outcomes despite treatment in long-standing diabetes 2, 9, 4
• Hypothyroidism: Increased prevalence 2, 9
• Age 40-65 years: Most common age range 9
• Female gender: Higher prevalence 4

Secondary Risk Factors

• Stroke patients: Up to 67% incidence when combined motor, sensory, and visuoperceptual deficits are present 1
• Shoulder tissue injury (effusion, tendinopathy, rotator cuff tears) 1
• Prolonged immobilization 4
• Cervical spondylosis 4
• Autoimmune rheumatic diseases 4

Clinical Pitfalls to Avoid

• Do not rely on imaging alone: The diagnosis is clinical, and normal radiographs do not exclude adhesive capsulitis 6, 2
• Do not confuse with rotator cuff pathology: In rotator cuff disease, passive range of motion is typically preserved while active motion is limited, whereas adhesive capsulitis shows equal restriction of both 1
• Do not assume self-resolution: While traditionally thought to be self-limited over 1-2 years, recent evidence shows persistent functional limitations if left untreated 2
• Screen diabetic patients proactively: Given the 14-20% prevalence in diabetics, routine screening can enable timely intervention 4