What is Sprengel's deformity?

Sprengel's Deformity

Sprengel's deformity is a rare congenital shoulder anomaly characterized by an abnormally high-riding, malpositioned, and dysplastic scapula resulting from failure of normal scapular descent during embryonic development. 1, 2

Pathophysiology and Clinical Features

The scapula fails to descend properly from its embryonic position at the cervical spine level (C4-C5) to its normal thoracic position (T2-T7) during weeks 9-12 of fetal development. 2 This results in:

• A small, high-riding scapula that is typically elevated, rotated, and dysplastic 1, 3
• Cosmetic deformity with visible shoulder asymmetry and potential neck webbing 3
• Functional limitation with restricted shoulder abduction (often <70°) and flexion (often <80°) 3
• Periscapular muscle atrophy and abnormal muscle attachments 1

Associated Anomalies

Sprengel's deformity commonly occurs with other congenital abnormalities, making screening essential. 2 Associated conditions include:

• Klippel-Feil syndrome (fused cervical vertebrae) in up to 40% of cases 3, 2
• Omovertebral bone or fibrous connection between the scapula and cervical spine (present in 30-50% of cases) 1, 3
• Scoliosis and rib anomalies 2
• Urogenital anomalies, suggesting renal tract screening should be performed 1

Diagnostic Evaluation

Plain radiographs combined with CT or MRI are necessary for complete assessment. 1 Evaluation should include:

• Clinical grading using the Cavendish classification system (grades 1-4 based on cosmetic severity) 1, 4
• Radiographic assessment using the Rigault classification (grades 1-3 based on scapular position) 1, 4
• Advanced imaging (CT/MRI) to identify omovertebral connections and associated spinal anomalies 1, 3
• Scapular ratio measurements to quantify elevation 1

Treatment Approach

Surgical management is warranted for moderate to severe cases (Cavendish grades 3-4), ideally performed before age 8 years to achieve optimal cosmetic and functional outcomes. 5

Surgical Techniques

The two most commonly employed procedures are:

• Green's procedure: Involves distal muscle reattachment, scapular lowering and rotation, with resection of the superomedial scapular portion fixed into a latissimus dorsi pocket 4
• Woodward procedure: Centers on scapular relocation through muscle detachment and reattachment at a lower level 4, 5

Both techniques achieve similar functional and cosmetic results, with success rates exceeding 80% and major complication rates under 3%. 5 The surgical goals include:

• Resection of omovertebral connections (bony or fibrous) 3, 5
• Inferior translation and derotation of the scapula 3, 5
• Resection of the protruding superomedial scapular portion 4, 2

Timing Considerations

Surgery performed before age 8 years yields superior cosmetic and functional outcomes compared to later intervention. 5 This timing allows:

• Better remodeling potential of the shoulder girdle
• Improved muscle adaptation to the new scapular position
• Enhanced cosmetic results during critical developmental years 5

Complications

Major complications occur in approximately 2-3% of cases, with brachial plexus palsy being the most concerning. 4, 5 Reported complications include:

• Transient brachial plexus palsy (typically resolves within 7 months) 4
• Recurrence of deformity (rare with proper technique) 5
• Wound complications and infection 5

Unique Anatomical Finding

Recent research has identified partial endomuscular ossification of medial scapular suspension muscles in severe cases, analogous to the cleithrum found in ancestral bony fish, suggesting this represents incomplete scapular descent rather than true "deformity." 1 This finding has led to the proposed terminology "congenital undescended scapula syndrome" to more accurately reflect the pathophysiology. 1