Introduction

Adhesive shoulder capsulitis, or arthrofibrosis aka, frozen shoulder, is a pathological process in which the body forms excessive scar tissue or adhesions across the glenohumeral joint, leading to pain, stiffness and dysfunction.

American Academy of Orthopedic Surgeons definition: Condition of varying severity characterized by the gradual development of global limitation of active and passive shoulder motion where radiographic findings other than osteopenia are absent.

• 2-5% prevalence in general population
• Self-limiting disease that resolves in approximately 1 years to 3 years

History

Simon-Emmanuel Duplay is widely recognized as the first physician to describe this pathology, which he called ‘scapulohumeral periarthritis’. ‘Periarthritis’ describes a painful shoulder syndrome that is distinct from arthritis with general radiographic preservation of the joint. 

Earnest Codman later coined the term ‘frozen shoulder’ in 1934 to emphasize the debilitating loss of shoulder motion in patients afflicted with this condition. He described this condition as ‘difficult to define, difficult to treat and difficult to explain from the point of view of pathology’.

In a pioneering histological study published in 1945, Julius Neviaser redefined this condition as adhesive capsulitis, underlying the inflammatory and fibrotic changes observed in the capsule or adjacent bursa.

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Classification

Primary or idiopathic adhesive capsulitis:

• Often associated with other diseases:
  • Diabetes mellitus
  • Thyroid disease
  • Drugs
  • Hypertriglyceridemia
  • Cervical spondylosis

Secondary adhesive capsulitis:

 

• Periarticular fracture dislocation of the glenohumeral joint
• Severe articular trauma:
  • Rotator cuff tears
  • Fractures
  • Immobilization
• Surgery:
  • Open or arthroscopic shoulder surgery (including rotator cuff repair and shoulder arthroplasty)

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Aetiology

Risk factors:

• Female sex (70% cases)
• Age > 40 years
• Preceding trauma
• HLA-B27 positivity
• Prolonged immobilization of the glenohumeral joint

Disease association:

• Diabetes (type I & II) (10-20% cases)
• Thyroid disease
• Cerebrovascular disease
• Coronary artery disease
• Autoimmune disease
• Dupuytren’s disease (52% cases)

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Pathoanatomy

Contracture of the glenohumeral capsule is the hallmark of adhesive capsulitis.

• Loss of the synovial layer of capsule
• Adhesions of axillary to itself and to anatomical neck of humerus
• Overall decreased capsular volume

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Clinical features

Shoulder pain followed by gradual loss of both active and passive range of motion (ROM) due to fibrosis of the glenohumeral joint capsule.

3 clinical phases:

• Phase 1 (painful/freezing phase):
  • Diffuse and disabling shoulder pain
    • Initially worse at night but then progresses to pain at rest
    • Associated with increasing stiffness
    • Last for 2-9 months
• Phase 2 (frozen/adhesive phase):
  • Progressive limitation in ROM in all shoulder planes but with the pain gradually becoming less pronounced
  • Last for 4-12 months
• Phase 3 (thawing/regression phase):
  • Gradual return of the range of motion
  • Takes 12-24 months for the complete return of ROM

Neviaser’s 4 classical stages of adhesie capsulitis:

• Stage I:
  • Shoulder pain (esp at night)
  • Preserved motion
  • Arthroscopy: Synovitis without adhesions/contractures
• Stage II:
  • Development of stiffness
  • Arthroscopy: Synovitis + some loss of the axillary fold, suggestive of early adhesion formation and capsular contracture
• Stage III (maturation stage):
  • Profound global loss of ROM and pain at extremes of motion
  • Arthroscopy: Synovitis is resolved but the axillary fold is obliterated as a result of significant adhesions
• Stage IV (chronic stage):
  • Persistent stiffness but minimal pain (as synovitis has resolved)
    • With pain controlled, patients may begin to exhibit slow improvement in shoulder mobility.
  • Arthroscopy: Advanced adhesions and restriction of the glenohumeral joint space

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Complications

• Residual shoulder pain and/or stiffness
• Humeral fracture
• Rupture of the biceps and subscapularis tendons

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Diagnosis

Imaging

Imaging studies are not necessary for the diagnosis of adhesive shoulder capsulitis but may be helpful to rule out other causes of a painful and stiff shoulder.

X-ray shoulder:

• Osteopenia (in patients with prolonged adhesive capsulitis secondary to disuse (i.e. disuse osteopenia))

Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA):

• Thickening of capsular and pericapsular tissues
• Contracted glenohumeral joint space

Histopathology

• Stage I: Inflammatory cell infiltration of synovium
• Stage II: Synovial proliferation
• Stage III: Dense collagenous tissue within the capsule

Differential diagnosis

• Septic arthritis
• Mal-position of orthopaedic hardware
• Fracture malunion
• Rotator cuff pathology
• Glenohumeral arthrosis
• Cervical radiculopathy

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Management

Goal of treatment is to restore the shoulder to a painless and functional joint.

Physical therapy (1st line management in early-stage disease):

• Range of motion exercises, stretching and graded resistance training
• Can be combined with:
  • Ultrasonic therapy
  • Transcutaneous electrical nerve stimulation
  • Short-wave therapy
  • Low-level laser therapy
  • Hydrotherapy

Pharmacotherapy:

• Non-steroidal anti-inflammatory drugs (NSAIDs):
  • Analgesia, esp. in initial, painful phase
• Oral (systemic) corticosteroids:
  • Short-term analgesia for improved ROM and function.
• Intra-articular corticosteroids
  • Improve function, decrease pain, and increase ROM
  • Sodium hyaluronate intra-articular injection
    • Has metabolic effects on articular cartilage, synovial tissue and synovial fluid

Suprascapular nerve block (SSNB):

• Provide temporary pain relief to facilitate mobilization

Hydrodilation aka distention arthrography or brisement:

• Capsular distention achieved by injection of air/fluid under fluoroscopy and local anesthetic to stretch the contracted capsule and thereby increasing the intracapsular volume

Whole-body cryotherapy (WBC):

• Exposure of the unclothed body in a chamber that circulates very cold air maintained between –110 ℃ to –140 ℃ for 2 minutes to 3 minutes to provide anti-inflammatory and analgesic effects

Surgical management:

• Manipulation under anesthesia (MUA)
  • Aggressive mobilization of the shoulder joint in a controlled setting beyond the normal pain thresholds to tear apart the adhesions and stretch the contracted capsule.

• Arthroscopic capsulotomy (arthroscopic capsular release)

• Open capsulotomy
  • When arthroscopic capsular release has failed in improving pain and ROM for adhesive capsulitis.

ACS Treatment	Goal	Treatment Modality
Painful phase	pain reduction and preservation of function	NSAIDs – i.a. steroid injections i.a. hyaluronate injections physiotherapy / hydrotherapy
Freezing phase	prevention of adhesion formation	NSAIDs – i.a. steroid injections capsular distension treatment physiotherapy
Frozen phase	ROM improvement	NSAIDs – i.a. steroid injections capsular distension treatment MUA arthroscopic release physiotherapy
Thawing phase	restoration of joint normal function	arthroscopic release open release physiotherapy