2. Classification
Defects of Segmentaion
Defects of Formation
Complex Spine Deformities
• Proposed by Moe et al
– Early concept
• Van Schrick
• Mac Ewen
• Accepted by SRS and AAOS
• Simplistic
– Ignores current understanding of embryogenesis
– Does not explain all deformities
3. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
4.
5.
6. Embryonic Period Anomalies
1st 56 Days
• Germinal layer adhesion
• Notochord substance sequestration
• Asynchronous hemimetameric pair
development
• Hemimetamer hypoplasia and aplasia
• Ventral and lateral process coalition
7.
8. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
9. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, 2004
10. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
11. Fetal Period Anomalies
57th day to Birth
• Vertebral joint failure of segmentation
• Centrum hypoplasia and aplasia
12. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
13. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
14. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
15. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
16. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
17. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
18. Tsou et al, Clinical Ortho and Related Research, No. 152, 1980
20. Genetics
• Wynne-Davies 1975
– 337 pts with congenital anomalies
– Most were sporadic with no risk to subsequent siblings of
offspring
– Multiple anomalies carried a 5~10% risk to sibs
• Winter 1983
– 1200 pts
– 1% with a known relative with a problem
• Most twin studies show one with a defect and one without
• McMaster et al JBJS, 1999,
– Positive family hx with multiple levels of bilateral failure of
segmentation, fused ribs, missing segments
– Spondylothoracic dysplasia or Jarcho-Levin syndrome
21. Associated Anomlies
• Renal 30% - Renal imaging is most important
image in pre-schoolers
• Cardiac 15% - Evaluate murmurs, they are never
due to the scoliosis
• Dysraphism 20+%
– Beware of skin anomalies
– Leg length discrepancy
– Neurological asymmetry
• Skeletal anomalies
Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, Vol 12, No. 4, 2004
22.
23.
24. Nomenclature
• Segmented – has disc space
• Incarcerated – adjacent level accommodates
hemi
Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, Vol 12, No. 4, 2004
25.
26. Midline Ectodermal Anomalies Correlate with
Neural Anomalies
• Skin tag
• Dimples
• Pigmentation
• Hair patch
Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, Vol 12, No. 4, 2004
34. Tethered Cord Not Just a Problem for Children
• Adults can present with tethered cord symptoms
– Increasing pain or neurologic loss of function
– Lower limb asymmetry or spasticity
• Do not be satisfied with images of only lumbar spine
37. Progression of Congenital Scoliosis
• Highly variable
• “Most progress” (10~20% nonprogressive)
– Unilateral bar with contralateral hemi – worst
– Unilateral unsegmented bar
– Double hemivertebra
– Single hemivertebra
– Wedge vertebra
– Block vertebra – best prognosis
McMaster and Ohtsuka,JBJS, vol 64, 1982
38. Location
• Thoracic curves with poorest prognosis
• Hemivertebra at lumbosacral and
cervicothoracic junction cause
decompensation
Lonstein, Congenital Spine Deformities, Ortho Clinics of NA, Vol 30, No.3, 1999
39. Non-operative Treatment
• Observation
– Not for high risk
– Hemivertebra and mixed deformity
• Bracing – limited role
– Contraindicated for short stiff curves
– ? Help for flexible curves
40. Lonstein, Congenital Spine Deformities, Ortho Clinics of NA, Vol 30, No.3, 1999
Treated with Observation
52. Rx with ant discectomies post instr with pedicle
screws at bifid vertebra and Galveston fixation
53. Kyphosis
• Kyphosis with centrum aplasia
– Sharp angular
– Risk of paraplegia
– Rx with circum-fusion +/- corpectomy
• Kyphosis with anterior bar
– Less neuro risk id not operated
– Surgical options customized
57. Lonstein, Congenital Spine Deformities, Ortho Clinics of NA, Vol 30, No.3, 1999
Progressive lordosis treated with ant discectomies, post fusion, and post-op cast
59. Conclusion
• Embryogenesis can be analyzed
• Progression is unpredictable with exceptions
– Bar with contralateral hemivertebra
– Kyphosis due to centrum aplasia
• Treatment
– Remove deforming growth elements
– Fusion-in-situ is no better than placebo