Bone and Soft-Tissue Disorders
Spondyloepiphyseal Dysplasia Congenita 
Autosomal dominant / sporadic (most)
- disproportionate dwarfism with spine + hips more involved than extremities
- waddling gait + muscular weakness
- flat facies; short neck; deafness
- cleft palate
- Axial skeleton
- ovoid vertebral bodies + severe platyspondyly (incomplete fusion of ossification centers + flattening of vertebral bodies)
- hypoplasia of odontoid process (Cx: cervical myelopathy)
- progressive kyphoscoliosis (short trunk) involving thoracic + lumbar spine
- narrowing of disk spaces → short trunk
- broad iliac bases + deficient ossification of pubis
- flat acetabular roof
- Chest
- bell-shaped thorax
- pectus carinatum
- Extremities
- normal / slightly shortened limbs
- severe coxa vara + genu valgum
- multiple accessory epiphyses in hands + feet
- talipes equinovarus
Cx:
- Retinal detachment, myopia (50%)
- Secondary arthritis in weight-bearing joints
Spondyloepiphyseal Dysplasia Tarda
= sex-linked recessive form with milder manifestation + later clinical onset
Age: apparent by 10 years; exclusive to males
- hyperostotic new bone along posterior ⅔ of vertebral end plate (PATHOGNOMONIC)
- platyspondyly with depression of anterior ⅓ of vertebral body
- narrowing with calcification of disk spaces + spondylitic bridging
- short trunk
- dysplastic joints (eg, flattened femoral heads)
- premature osteoarthritis
DDx: Ochronosis