Epiphyseal Dysplasias

Multiple epiphyseal dysplasia

Characterised by late appearance of epiphysis, knobbly joints, stubby digits and minimal shortness of stature.

Inheritance

• Autosomal Dominant
• Prevalence 10-15 / million
• Age at diagnosis 1-2 years (later in milder cases)

Clinical Features

• First suspected due to delayed walking
• Normal intelligence

X-Rays

• Delayed development 
• Irregular epiphyses
• Epiphyses are flattened (in the hips looks like Perthes)

Pathology

• Disordered development of epiphseal ossification centres
• Articular cartilage becomes irregular and may lead to early OA
• Number of epiphyses involved varies
• Femur and Humerus common sites
• Skull facial bones and pelvis are normal

Differential Diagnosis

Bilateral Perthes (other epiphyses affected)

Treatment

• Symptomatic
• CPM may help joint congruity
• Total joint replacements once OA has progressed 

Prognosis

Normal life expectancy

Dysplasia epiphysealis hemimelica

Inheritance

Unknown

Incidence

• Extremely rare, less than 1 / million
• Age at diagnosis early childhood
• Male : Female 3:1

Clinical Features

• Becomes evident in early childhood with bony lump or stiffness
• Usually unilateral involvement with one limb and only half of the epiphysis
• Common sites are tarsus, distal femur and proximal tibia
• Irregular bony masses protrude form the epiphysis
• 70% present with deformity

X-Rays

• Irregular often multi-centric bony protrusion develops from the affected epiphysis
• Similar to an exostosis, but originates from the epiphysis not the metaphysis

Pathology

• Similar to an osteo-cartilaginous exostosis
• Either a cartilage capped pedunculated mass or irregular expansion of the articular surface

Treatment

Excision, if interferes with function

Prognosis

• Usually stops growing at skeletal maturity
• Malignant change has not been reported
• Normal life expectancy

Spondyloepiphseal dysplasia

Classification

• Congenita (severe form)
• Tarda (mild form)

Inheritance

• Congenita
  • Autosomal dominant
  • Most are sporadic
  • Prevalence 1-2 / million
  • Age at diagnosis 3-4 years
• Tarda
  • X linked recessive
  • Prevalence 3-4 / million
  • Age at diagnosis 5-10 years 
  • Males only

Clinical Features

• Congenita
  • Associated with severe coxa vara and disproportionate short stature, abnormal epiphyses and vertebra plana
  • Femoral head ossification not until 5 years
  • Vertebrae are flattened throughout and pear shaped
  • Associated  with CDH
  • Odontoid malformation causes atlanto-axial instability
  • Scoliosis and kyphosis develops in late childhood or early adolescence
  • Other abnormalities associate (TEV, hernia, myopia cleft palate)
• Tarda
  • Flattened vertebrae and intervertebral discs
  • Posterior spinal hump
  • Back pain at age 5-10 years
  • Proximal femur and humerus minimally involved

X-Rays

• Posterior wedging of vertebrae
• Platyspondyly
• Unossified femoral heads until adolescence
• Hypoplasia of odontoid

Pathology

Disorder of Type II collagen

Treatment

• Congenita
  • Atlanto-axial instability most serious problem
  • Coxa vara may require osteotomy
• Tarda
  • Conservative
  • Most deformities usually not severe