Congenital scoliosis

Congenital Scoliosis

Richard C Rooney, MD, FACSrrooney@seattlespinegroup.com

ClassificationDefects of Segmentaion

Defects of FormationComplex 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

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Embryonic Period Anomalies1st 56 Days

• Germinal layer adhesion• Notochord substance sequestration• Asynchronous hemimetameric pair

development• Hemimetamer hypoplasia and aplasia• Ventral and lateral process coalition

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, 2004

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Fetal Period Anomalies57th day to Birth

• Vertebral joint failure of segmentation• Centrum hypoplasia and aplasia

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Tsou et al, Clinical Ortho and Related Research, No. 152, 1980

Lonstein, Congenital Spine Deformities, Ortho Clinics of NA, Vol 30, No.3, 1999

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

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

Nomenclature• Segmented – has disc space• Incarcerated – adjacent level accommodates

hemi

Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, Vol 12, No. 4, 2004

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

Midline skin anomalies may mean neural anomalies

Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, Vol 12, No. 4, 2004

Evaluation of Entire Spinal Canal• Search for anomalies

– Chiari malformation– Syringomyelia– Diatematomyelis– Filum terminale– Lipoma– Tumor

• Indication– Pre-op– Neurologic deficit or asymmetry– Lower limb asymmetry– Every pt with a congenital defect?

Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, Vol 12, No. 4, 2004

Diastematomyelia

Diastematomyelia Radiographic Signs

• Widened interpedicular distance• Narrowed disc• Midline calcification

Winter Sign Asymmetrical forward bend is consistent with

a tethered cord

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

Lonstein, Congenital Spine Deformities, Ortho Clinics of NA, Vol 30, No.3, 1999

Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, Vol 12, No. 4, 2004

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

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

Non-operative Treatment• Observation

– Not for high risk– Hemivertebra and mixed deformity

• Bracing – limited role– Contraindicated for short stiff curves– ? Help for flexible curves

Lonstein, Congenital Spine Deformities, Ortho Clinics of NA, Vol 30, No.3, 1999

Treated with Observation

Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, Vol 12, No. 4, 2004

Surgical Rx

• Fusion-in-situ– Simple– Ineffective

• Anterior epiphysiodesis & posterior hemiarthrodesis– Progressive deformity– Growing patient

• Combined anterior posterior fusion• Hemivertebra excision

Lonstein, Congenital Spine Deformities, Ortho Clinics of NA, Vol 30, No.3, 1999

Convex Growth Arrest at 2+8

Hedequist and Emans, Congenital Scoliosis, Journal of AAOS, Vol 12, No. 4, 2004

Lonstein, Congenital Spine Deformities, Ortho Clinics of NA, Vol 30, No.3, 1999

Ant excision of hemivert and post instrumentation and fusion

Congenital Scoliosis with Myelodysplasia

Rx with ant discectomies post instr with pedicle screws at bifid vertebra and Galveston fixation

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

Lordosis • Anterior fusion – small curve• Anterior / posterior procedure – large

curves

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

Lonstein, Congenital Spine Deformities, Ortho Clinics of NA, Vol 30, No.3, 1999

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