1. Characterizing Escobar Syndrome: Frequent Congenital Anomalies, Helped by Growth-Friendly Surgery
Adam Margalit, BS
Paul D. Sponseller, MD
Richard McCarthy, MD
Jeff Pawelek
Lynn McCullough, RNP, MSNc, ONC
Richard Schwend, MD
Amer Samdani, MD
Behrooz A. Akbarnia, MD
Children’s Spine Study Group
Growing Spine Study Group
INTERNATIONAL CONGRESS ON EARLY ONSET SCOLIOSIS
November 17-18, 2016 / Utrecht, Holland

2. INTRODUCTION
Escobar Syndrome is an autosomal recessive disorder caused by a mutation in the fetal γ-subunit of the acetylcholine receptor leading to fetal akinesia
In addition to arthrogryposis, the predominant clinical characteristics are limb pterygia and spinal deformity
Treating children with early-onset scoliosis (EOS) secondary to Escobar Syndrome is not well described in the literature
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3. METHODS Hypothesis: Patients with EOS secondary to Escobar Syndrome:
Have unique spinal deformity characteristics
Growth friendly constructs will improve curve severity while allowing for spinal growth
Have less T1-S1 height gain and decreased curve control after surgical correction compared to an idiopathic EOS cohort secondary to congenital anomalies
Study Design:
Multicenter review of retrospective and prospective data
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4. METHODS Inclusion Criteria: Comparison Group:
EOS associated with Escobar Syndrome
Treated with growth-friendly surgical techniques [growing rods, Shilla technique, vertical expandable prosthetic titanium rib (VEPTR)]
Minimum post-operative follow-up of 2 years
Comparison Group:
An idiopathic EOS cohort was identified and matched (1:2) for:
Pre-op age (± 1 year)
Duration of follow-up (± 1 year)
Curve magnitude (± 20°)
Growth friendly device
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5. RESULTS
Out of 39 arthrogryposis patients, 8 patients with Escobar Syndrome were identified
Treatment types included:
Traditional Growing Rods (n=3)
Shilla (n=2)
VEPTR (n=3)
Mean age at surgery:
5.0 years old (range: )
Mean follow-up:
7.3 years (range: )
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Growing Rods
Shilla
VEPTR

6. RESULTS Spinal deformity involved 7-13 vertebrae
No congenital anomalies (n=3) vs multiple defects (n=5)
Congenital anomalies included:
1-3 blocks with 2-9 fused vertebrae per block
1-2 hemivertebrae
1-2 unilateral bars involving 2-4 vertebrae
Comorbidities included tethered cord (n=2), torticollis (n=2), and hip dislocations (n=1)
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7. RADIOGRAPHIC RESULTS Escobar Cohort: Mean major curve correction:
Pre-op = 76°
Post-op = 43° (p=0.001)
Latest follow up = 37° (p=0.001)
Mean gain in spinal height (T1-S1):
Pre-op = 223 mm
Latest follow up = 306 mm (p=0.002)
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8. RADIOGRAPHIC RESULTS
Escobar patient treated with traditional growing rods
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10 years old (Growing rods) T1-S1: 29 cm
14 years old (Final fusion) T1-S1: 36 cm
7 years old T1-S1: 24 cm

9. RESULTS: ESCOBAR VS. IDIOPAATHIC
16 matched patients with idiopathic EOS were identified
Escobar
Idiopathic
Sample size (n) 8 16
Age at first surgery (yr)
5.0
5.3
Mean follow-up (yr)
7.3
6.8
Major curve at presentation (°) 76 74
Major curve after first surgery (°) 43
Major curve at final follow-up (°) 37 54
T1 - S1 length at presentation (mm)
223
247
T1 - S1 length at final follow-up (mm)
306
348
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10. RESULTS: ESCOBAR VS. IDIOPAATHIC
No difference in curve correction between groups:
Initial procedure (42 vs. 42%, p=0.99)
Latest follow-up (39 vs. 59%, p=0.23)
Escobar patients grew on average 10 mm/yr in the T1-S1 segment compared to 11 mm/yr in idiopathic EOS patients (p=0.78)
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11. RESULTS: ESCOBAR VS. IDIOPAATHIC
Complications:
Of note, there were no neurological deficits observed in both groups
Escobar
Idiopathic
Rod fracture 11 4
Screw pullout 2
Proximal junctional kyphosis
Medical-related complications 3 5
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12. CONCLUSION
Multiple congenital fusions, trunk imbalance, and tethered cord are common in Escobar Syndrome
Despite large areas of fusion, growth friendly constructs improve trunk balance, facilitate spinal growth, and improve curve correction, which are comparable to the idiopathic EOS population
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