Congenital Abnormalities (Anatomy)

Question 1

How are long bones formed?

Answer 1

• Long bones are formed through the process of endochondral ossification.
• This is the formation of bone from a cartilaginous template.
• The formation of separate ossification centres ensures an epiphyseal growth plate remains.
• This plate allows long bone growth (as the name suggests).

Question 2

How do the bones of the skull ossify?

Answer 2

Intramembranous ossification

Question 3

What is radiological ageing?

Answer 3

• This is a process by which skeletal maturity is assessed. It is most commonly performed from radiographs.
• A radiologist can determine bone age from:

1. The degree of fusion of epiphyses and diaphyses.
2. The presence or absence of calcified material in specific bones.

• Usually requested by paediatricians and endocrinologists as, by comparing bone age and chronological age, disease can be diagnosed

Question 4

What is a useful site for determining age in children?

Answer 4

• The carpal bones ossify at different times throughout childhood, meaning that the wrist is a useful site for determining bone age in children.
• The timing of this process is fairly constant, but the bones of females do ossify faster than those of males.

Question 5

What are the carpal bones and locate them?

Answer 5

Question 6

What can failures of developmental signalling pathways and processes involved in osteogenesis result in?

Answer 6

This results in congenital abnormalities such as:

• Spina bifida
• Polydactyly
• Syndactyly
• Amelia
• Meromelia

Question 7

What is spina bifida?

Answer 7

This is a condition where in some of the vertebral lamina (usually of the lumbar region) do not develop properly and so do not protect the spinal cord posteriorly.

This can manifest in a number of way.

Question 8

What are the types of spina bifida?

Answer 8

There are multiple types of spina bifida, of varying degrees of severity.

• Spina bifida occulta is the most common and most mild form.
• Meningomyelocele is the most severe form.

Question 9

What are the consequences of spina bifida?

Answer 9

• This lack of protection of the spinal cord will increase the likelihood and severity of damage.
• If the spinal cord is exposed to the open air, there is also an increased risk of infection.
• Symptoms can also include:
  
  • Seizures
  • Hydrocephalus
  • Loss of sensation
  • Paralysis

Question 10

What is polydactyly?

Answer 10

Polydactyly is the presence of more than five digits on the hands or feet.

Question 11

What is syndactyly?

Answer 11

Syndactyly is the fusion*** or ***webbing of the digits of the hands or feet.

Question 12

What is bidactyly?

Answer 12

Bidactly is the presence of only radial and ulnar or tibial and fibular digits.

Question 13

What is amelia?

Question 14

What is meromelia?

Answer 14

This is the absence of a part of a limb.