Updated: 10/26/2017

Sacral Agenesis

Topic
Review Topic
0
0
Questions
2
0
0
Evidence
2
0
0
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Introduction
  • Condition characterized by partial or complete absence of sacrum and lower lumbar spine
  • Epidemiology
    • incidence
      • 1 - 2.5 per 100,000 newborns
    • risk factors
      • highly associated with maternal diabetes
  • Pathophysiology
    • neurologic involvement
      • motor deficit corresponds to level
      • protective sensation is usually intact
        • important in that there is a lesser rate of decubiti ulcers
        • this differentiate from myelodysplasia
  • Associated conditions
    • caudal regression syndrome
      • gastrointestinal disorders (imperforate anus)
      • genitourinary disorders
      • cardiovascular disorders
      • lower extremity deformities
      • progressive kyphosis
Classification
 
Renshaw Classification
Type I Partial or total unilateral sacral agenesis
 
Type II Partial sacral agenesis with a bilaterally symmetrical defect
 
Type III Ilium articulating with the sides of the lowest vertebra present
 
Type IV Caudal endplate of vertebra resting above fused ilia or an iliac amphiarthrosis   
 
Presentation
  • Symptoms
    • clinical presentation is based on the severity of disease
  • Physical exam
    • inspection
      • prominence of the last vertebral segment
        • classic sign of buttock dimping 
      • postural abnormalities (e.g. sitting buddha) 
      • limb and joint contractures
        • extended knees, flexed hips, and equinovarus feet.
    • motion
      • flexion and extension may occur at the junction of the spine rather than hips
    • neurovascular examination
      • motor and sensory deficits are common in severe disease
Treatment
  • Nonoperative
    • physical therapy
      • indications
        • Renshaw type 1/2
      • outcomes
        • most become community ambulators
        • foot and knee deformities to be addressed
  • Operative
    • spinal stabilization procedures
      • indications
        • Renshaw type 3/4 with progressive kyphosis or scoliosis
      • outcomes
        • progressive kyphosis and/or scoliosis may develop between the spine and pelvis
        • child must use his or her hands to support the trunk, and therefore is unable to use his or her hands for other activities
    • limb amputation
      • indication
        • non-fuctional lower limb deformities
      • outcomes
        • better mobility 
Complications
 
 

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Questions (2)

(SAE07PE.59) A full-term newborn has webbing at the knees, rigid clubfeet, a Buddha-like posture of the lower extremities, and no voluntary or involuntary muscle action at and below the knees. Radiographs of the spine and pelvis reveal an absence of the lumbar spine and sacrum. What maternal condition is associated with this diagnosis? Review Topic

QID: 6119
1

Alcoholism

0%

(0/1)

2

Drug abuse

0%

(0/1)

3

Down syndrome

0%

(0/1)

4

Diabetes mellitus

100%

(1/1)

5

Idiopathic scoliosis

0%

(0/1)

N/A

Select Answer to see Preferred Response

PREFERRED RESPONSE 4

(SAE07PE.12) A 2-year-old boy has complete absence of the sacrum and lower lumbar spine. What is the most likely long-term outcome if no spinal pelvic stabilization is performed? Review Topic

QID: 6072
1

Progressive paralysis

17%

(7/42)

2

Neck extension contracture

0%

(0/42)

3

Inability to sit without using the hands for support

69%

(29/42)

4

Progressive hip dislocation

12%

(5/42)

5

Sexual dysfunction

2%

(1/42)

N/A

Select Answer to see Preferred Response

PREFERRED RESPONSE 3
ARTICLES (2)
Topic COMMENTS (0)
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