Physical Address

304 North Cardinal St.
Dorchester Center, MA 02124

Kyphosis


KEY FACTS

Terminology

  • Spinal curvature secondary to vertebral anomalies

  • Hemivertebra: Unilateral or anterior vertebral hypoplasia

  • “Butterfly” vertebra: Central vertebral cleft due to failure of central vertebral body development

  • “Fused” vertebrae: Embryological failure of segmentation rather than fusion

  • Klippel-Feil syndrome: Multiple cervical segmentation anomalies

Imaging

  • Accentuated dorsal thoracic spine curvature on lateral image

  • Look for vertebral anomalies in patient with scoliosis or kyphosis

  • May have multiple kyphotic and scoliotic curves if multiple anomalies present

Top Differential Diagnoses

  • Scheuermann kyphosis

  • Idiopathic kyphosis

  • Kyphosis or scoliosis due to syndromes

  • Traumatic kyphosis

  • Osteomyelitis, granulomatous

Pathology

  • May be congenital or acquired

  • Fetal insult in 1st trimester causing abnormal development &/or segmentation of vertebrae

  • Congenital abnormalities due either to failure of development &/or failure of segmentation

Clinical Issues

  • May be isolated anomaly or associated with multisystem anomalies (VACTERL)

Diagnostic Checklist

  • Image entire spine (particularly in children) to exclude additional bone or cord abnormalities, Chiari 1 malformation

Lateral radiograph demonstrates smoothly curved thoracic kyphosis, with premature upper thoracic degenerative disc disease
, in this patient with degenerative kyphosis.

Lateral chest radiograph (idiopathic kyphosis) reveals diffuse upper thoracic kyphosis with a round-back deformity. There is no underlying cause of kyphosis (e.g., Scheuermann disease, prior trauma, congenital anomaly, or infection).

Lateral 3D reformation CT shows a posterior hemivertebra
fused to the vertebra below and causing kyphoscoliosis. Congenital scoliosis is often complex in morphology and most easily appreciated on 3D reformations.

Sagittal T2WI MR of a child with a repaired high myelomeningocele and congenital vertebral segmentation failure
shows severe focal lumbosacral kyphotic curvature
.

TERMINOLOGY

Definitions

  • Accentuated thoracic ± reduced normal cervical, lumbar lordotic spinal curvature

    • Spinal curvature secondary to vertebral anomalies, degenerative spine disease, or idiopathic causes

IMAGING

General Features

  • Best diagnostic clue

    • Accentuated dorsal thoracic spine curvature on lateral image

    • Vertebral anomaly in patient with scoliosis or kyphosis

  • Location

    • Most common in thoracic spine but can occur at any spinal level

  • Morphology

    • Butterfly vertebra: Central vertebral cleft due to failure of central vertebral body development

    • Hemivertebra: Unilateral or anterior vertebral hypoplasia

    • “Fused” vertebrae: Embryological failure of segmentation rather than fusion

      • –

        Also called block vertebrae; may affect vertebral body, posterior elements, or both

      • –

        Affected vertebrae narrow in mediolateral and anteroposterior dimensions

      • –

        Rudimentary disc may be present

    • Vertebral bar

      • –

        Bony or cartilaginous connection between adjacent vertebrae

      • –

        Often associated with rib fusions

Radiographic Findings

  • Accentuated dorsal curvature of thoracic spine &/or reduced lordotic curvature of cervical, lumbar spine

  • Abnormal vertebral bodies, hemivertebrae, fused ribs in congenital kyphosis

  • Nonsegmented vertebrae often have decreased AP dimension

    • Helps to distinguish from fusion occurring in adulthood

  • Single or multiple curves

  • Vertebral anomalies are often difficult to see; use coned-down radiographs, MR, or CT to clarify

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here

Related Posts