What is a Sprengel deformity?

Sprengel Deformity: Definition and Clinical Features

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

Pathoanatomy and Embryology

• The deformity occurs due to arrested descent of the scapula during fetal development, typically between the 9th and 12th weeks of gestation, leaving the scapula in an abnormally high position 2
• The scapula is characteristically small, high-riding, dysplastic, and medially rotated with the inferior pole rotated medially 1, 3
• An omovertebral bar (bony, cartilaginous, or fibrous connection between the scapula and cervical spine) is present in approximately 30-50% of cases 2, 4
• Recent anatomical observations have identified partial endomuscular ossification of medial scapular suspension muscles, analogous to the cleithrum found in archaic bony fish, suggesting this represents incomplete scapular descent rather than true "deformity" 1

Clinical Presentation

Patients present with visible cosmetic deformity and functional shoulder limitations:

• Asymmetric shoulder height with one shoulder elevated and appearing smaller 2, 3
• Webbed neck appearance (lateral neck skin fold extending from mastoid to acromion) in more severe cases 4
• Limited shoulder abduction (typically <70-115°) and flexion (<80-115°) 3, 4
• Periscapular muscle atrophy and weakness 1, 2
• The deformity can be unilateral (most common) or bilateral 4

Associated Conditions

Sprengel deformity rarely occurs in isolation and requires systematic evaluation for associated anomalies:

• Klippel-Feil syndrome (fusion of cervical vertebrae) is the most common association, present in 30-60% of cases 2, 5, 4
• Congenital scoliosis occurs in 50-60% of patients 2, 5
• Rib anomalies including fused, absent, or supernumerary ribs 2
• Split cord malformations and other spinal dysraphism 6, 5
• Tethered cord syndrome with lumbar spina bifida occulta can present with progressive lower limb weakness and gait abnormalities 5
• Renal and urogenital anomalies warrant screening given the association between scapular and urogenital developmental pathways 1

Diagnostic Evaluation

Initial assessment should include:

• Plain radiographs of the shoulder and cervical spine to identify scapular position, omovertebral connections, and vertebral anomalies 2, 4
• MRI is the preferred imaging modality to evaluate soft tissue structures, omovertebral connections, and associated spinal cord abnormalities including tethered cord 6, 5
• CT scanning can provide detailed bony anatomy for surgical planning 4
• Comprehensive neurological examination focusing on signs of myelopathy, radiculopathy, or tethered cord syndrome is essential, as this is more than a cosmetic problem 5
• Renal ultrasound screening should be considered given the association with urogenital anomalies 1

Classification Systems

• Cavendish grading (grades 1-4) assesses cosmetic severity based on shoulder height asymmetry 1, 3
• Rigault classification (grades 1-3) evaluates radiographic severity based on scapular position relative to thoracic vertebrae 1

Important Clinical Pitfall

Diagnostic confusion with limited scoliosis can be dangerous because it may delay proper treatment of other serious abnormalities (such as tethered cord or Klippel-Feil syndrome) that may be present even in mild cases of Sprengel deformity 2