What is the diagnosis and treatment for scapular winging?

Diagnosis and Treatment of Scapular Winging

Scapular winging is a condition characterized by abnormal protrusion of the scapula from the thoracic wall that requires prompt diagnosis and targeted treatment to prevent substantial shoulder dysfunction and disability.

Diagnosis

Clinical Presentation

• Patients typically present with diffuse neck, shoulder girdle, and upper back pain that worsens with abduction and overhead activities 1
• Scapular winging often mimics more common shoulder conditions, leading to misdiagnosis as rotator cuff disorders, glenohumeral instability, cervical spine disease, or thoracic outlet syndrome 2
• Visual inspection reveals abnormal positioning of the scapula away from the thoracic wall 3

Types of Scapular Winging

• Medial winging: The medial border of the scapula protrudes from the thoracic wall, most commonly due to serratus anterior muscle paralysis (long thoracic nerve injury) 3
• Lateral winging: The lateral border protrudes, typically caused by trapezius muscle paralysis (spinal accessory nerve injury) 3
• Inferior angle winging with lateral rotation: Caused by rhomboid muscle paralysis (dorsal scapular nerve injury) 4

Physical Examination

• Examine for scapular dyskinesis during arm elevation - normally, the scapula should rotate upward and tilt posteriorly 5
• Assess for shoulder impingement signs and scapular winging or dyskinesia, particularly in patients with history of head and neck cancer treatments, as spinal accessory nerve injury may be present 5
• Evaluate rotator cuff strength, as weakness may coexist with scapular winging 5
• Test for specific muscle weakness:
  • Serratus anterior: Forward flexion against resistance
  • Trapezius: Shoulder shrugging against resistance
  • Rhomboids: Scapular retraction against resistance 4

Diagnostic Studies

• Electromyography (EMG) and nerve conduction studies are essential for confirming the diagnosis and identifying the specific nerve injury 2
• Radiographs should be obtained to rule out structural causes such as osteochondromas 6
• CT may be necessary if scapular fractures are suspected 5
• MRI may be indicated to evaluate for associated rotator cuff pathology or other soft tissue abnormalities 5

Treatment

Conservative Management

• A 6-24 month course of conservative treatment is recommended initially to allow for spontaneous recovery, particularly for serratus anterior paralysis which often resolves within 24 months 3
• Conservative treatment includes:
  • Physical therapy focusing on strengthening of the rotator cuff and scapular stabilizers 5
  • Restoration of proper shoulder mechanics and spine positioning 5
  • Range of motion exercises to prevent adhesive capsulitis 5

Specific Rehabilitation Protocols

• For serratus anterior weakness: Focus on strengthening exercises that target this muscle specifically, such as wall push-ups with emphasis on scapular protraction 5
• For trapezius weakness: Exercises that focus on scapular elevation, retraction, and upward rotation 3
• For rhomboid weakness: Targeted scapular retraction exercises, though outcomes may be less favorable than with other types 4

Surgical Management

• Surgical intervention is considered when:
  • Conservative treatment fails after 6-24 months
  • No signs of spontaneous recovery are observed
  • Functional disability persists 3
• Surgical options include:
  • Nerve transfers or grafting for neurogenic causes
  • Muscle transfers for permanent nerve damage
  • Scapulothoracic fusion in severe cases 1
• For structural causes such as osteochondromas, surgical resection may be required 6

Special Considerations

Underlying Etiologies

• Traumatic causes (most common): Direct injury to nerves from trauma or overuse 2
• Iatrogenic causes: Surgical procedures involving the neck or axilla 2
• Idiopathic causes: No identifiable cause 3
• Structural causes: Osteochondromas or other bony abnormalities 6
• Neuromuscular diseases: Such as limb-girdle muscular dystrophy may present with scapular winging 5

Common Pitfalls

• Misdiagnosis is common, leading to unnecessary or unsuccessful surgical procedures for presumed rotator cuff disorders, instability, or cervical spine disease 2
• Failure to obtain EMG/nerve conduction studies can lead to missed diagnosis of the specific nerve injury 2
• Overlooking structural causes such as osteochondromas, especially in pediatric or adolescent patients with relapsing and remitting symptoms 6
• Inadequate follow-up during conservative treatment may miss opportunities for intervention if no improvement occurs 3

Prognosis

• Serratus anterior paralysis: Most cases spontaneously resolve within 24 months with conservative treatment 3
• Trapezius paralysis: Conservative treatment is less effective, and surgical intervention may be required more frequently 3
• Rhomboid paralysis: Conservative treatment is typically recommended, but complete correction of winging may not be achieved 4

By understanding the specific cause of scapular winging and implementing appropriate treatment strategies, clinicians can help patients avoid substantial shoulder dysfunction and improve their quality of life.