Congenital Abnormalities ✅ Flashcards Preview

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Flashcards in Congenital Abnormalities ✅ Deck (65)
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1
Q

What are the categories of congenital limb defects?

A
  • Reduction defects
  • Duplication defects
  • Dysplasia (malformation)
2
Q

What are the types of reduction defects?

A
  • Entire limb (amelia)

- Part of limb (meromelia)

3
Q

What happens in duplication defects?

A

There are extra limb elements

4
Q

What is the most common duplication defects?

A

Extra digits (polydactyly)

5
Q

Give 2 examples of limb dysplasia?

A
  • Fusion of digits (syndactyly)

- Excessive growth of parts of the limb (gigantism)

6
Q

What processes can limb defects be broadly attributed to?

A
  • Developmental arrest (failure to form)
  • Failure of differentiation
  • Duplication
  • Overgrowth (hyperplasia)
  • Undergrowth (hypoplasia)
  • Focal defects
  • General skeletal abnormalities
7
Q

Give an example of a focal defect causing limb defects

A

Amniotic fluid band syndrome

8
Q

Give an example of a general skeletal abnormality causing limb defects

A

Osteogenesis imperfecta

9
Q

What is true of most limb defects?

A

They have multifactorial aetiologies with a combination of genetic and environmental factors (but either may predominate)

10
Q

Give an example of a limb malformation where genetic causes predominante?

A

Polydactyly or ectrodactyly (absence of fingers or toes)

11
Q

How does postaxial hand polydactyly differ between black and white children?

A

In black children it is commonly an isolated disorder, and is autosomal dominant.
In white children it is usually syndromic, and is autosomal recessive

12
Q

What causes DDH?

A

Not clear, but usually multifactorial

13
Q

What are the risk factors for DDH?

A
  • Female gender
  • Family history
  • Oligohydramnios
  • Breech position
  • Presence of other congenital abnormalities, e.g. neuromuscular disorders
14
Q

Describe the hip joint in normal development

A

The head of the femur is smooth and rounded, and the acetabulum is cup-shaped

15
Q

Describe the hip joint in DDH

A

There may be abnormalities of the shape of the head of the femur, acetabulum, or surrounding structures, meaning the acetabulum and femur may not be in close contact

16
Q

What might happen to the hip in DDH?

A

Depending on degree of abnormality, may be subluxed or dislocated

17
Q

What is talipes equinovarus?

A

A complex abnormality where;

  • The entire foot is inverted and supinated
  • The forefoot adducted
  • The heel is rotated inwards and in plantar flexion
  • The affected foot is shorter, and the calf muscles thinner than normal
18
Q

Can the position of the foot be corrected with passive manipulation in talipes equinovarus?

A

No, it is fixed and cannot be corrected completely

19
Q

Is talipes equinovarus unilateral or bilateral?

A

Often bilateral

20
Q

What gender is talipes equinovarus more common in?

A

Males (2:1)

21
Q

Its talipes equinovarus familial?

A

Can be, but usually idiopathic

22
Q

What might talipes equinovarus be secondary to?

A
  • Oligohydraminos
  • Malformation syndrome
  • Neuromuscular disorder such as spina bifida
23
Q

What is used to treat talipes equinovarus?

A

The Ponseti method

24
Q

What is the Ponstei method?

A

Manipulative technique involving serial casting

25
Q

What is the advantage of the Ponseti method?

A

It usually avoids the need for invasive surgery

26
Q

What does talipes equinovarus need to be differentiated from?

A
  • Positional talipes

- Vertical talus

27
Q

How is talipes equinovarus differentiated from positional talipes?

A

In positional talipes:

  • The foot is of normal size
  • Deformity is mild and can be corrected with passive manipulation
28
Q

What are the features of vertical talus?

A

Foot is stiff and rocker-bottom in shape

29
Q

What is talipes equinovarus often associated with?

A

Other malformations

30
Q

What are the environmental causes of limb defects?

A
  • Drug teratogens

- Amniotic tissue/constricted uterus

31
Q

At what time are developing foetuses particularly vulnerable to drugs causing limb defects?

A

4-8 weeks gestation

32
Q

What drug teratogens may lead to limb defects?

A
  • Thalidomide
  • Any drug which influences general cell metabolism or cell proliferation
  • Warfarin
  • Phenytoin
  • Valproic acid
  • Acetazolamide
33
Q

How does thalidomide cause limb defects?

A

It disrupts cell adhesion receptors and inhibits angiogenesis

34
Q

What limb defects are associated with thalidomide exposure?

A
  • Amelia and phocomelia

- Minor deformities, e.g. thumb hypoplasia, syndactyly between index finger and thumb

35
Q

Give an example of a drug that influences cell metabolism/proliferation

A

Triethylene melamine (chemotherapy alkylating agent)

36
Q

What does limb growth in uterus require?

A

Physical space

37
Q

When might space in utero be restricted leading to limb deformities?

A
  • Constricted uterine environment, e.g. bicornuate uterus

- Intrauterine compression, e.g. multiple pregnancy

38
Q

What is an amniotic band?

A

When fibrous amniotic tissue detatches and wraps around the developing limb

39
Q

What can the consequence of an amniotic band be?

A

It can prevent growth or development of a limb or part of a limb

40
Q

What is the prevalence of amniotic band syndrome?

A

Affects up to 1 in 1200 live births

41
Q

What is amniotic band syndrome associated with?

A

Increased risk of other abnormalities, e.g. cleft lip and palate, talipes equinovarus

42
Q

What might cause congenital structural defects of the spine?

A

Failure of vertebrae formation, separation, or fusion

43
Q

What are the types of spinal abnormality?

A
  • Scoliosis
  • Kyphosis
  • Lordosis
44
Q

What is scoliosis?

A

Where the spine develops to the left or right

45
Q

What is kyphosis?

A

When the spine has a convex overcurvature

46
Q

What is lordosis?

A

When the spine sways backwards

47
Q

What does the involvement of the vertebra growth plate influence?

A

The growth potential

Differences in progression and deformity

48
Q

What is the most common developmental spine condition?

A

Congenital scoliosis

49
Q

What causes congenital scoliosis?

A

The aetiology is not fully known, but failure of sclerotome segmentation results in vertebrae that are abnormally connected on one side, causing asymmetrical growth rates.
There may also be disruption of the normal shape of the vertebra, causing a wedge shape, which can cause asymmetrical growth.

50
Q

Is congenital scoliosis the same thing as idiopathic scoliosis?

A

No

51
Q

What are the categories of presentation of idiopathic scoliosis?

A
  • Early onset (under 5 years)

- Late onset

52
Q

What is the most common presentation of idiopathic scoliosis?

A

Late-onset, mainly in girls 10-14 years of age during their pubertal growth spurt

53
Q

Is secondary scoliosis common?

A

Yes

54
Q

What can cause secondary scoliosis?

A
  • Disorders that result in neuromuscular imbalance
  • Disorders of bone or cartilage
  • Leg length discrepancy
55
Q

Give 3 examples of disorders that result in neuromuscular imbalance

A
  • Cerebral palsy
  • Muscular dystrophy
  • Polio
56
Q

Give 2 examples of disorders of bone or cartilage that may lead to scoliosis?

A
  • Neurofibromatosis

- Marfan’s syndrome

57
Q

What should be done if a child has a congenital vertebral abnormality?

A

Other systems should be investigated to exclude syndrome characteristics, e.g. VACTERL association

58
Q

What is arthrogyposis?

A

The collective term for a number of conditions associated with joint contractures at birth

59
Q

What can result in joint contractures at birth?

A

Factors that inhibit normal joint development or movement (intrinsic or extrinsic)

60
Q

Give 2 examples of extrinsic factors that may cause joint contractures?

A
  • Oligohydraminos

- Viral infections

61
Q

What intrinsic factors might cause joint contractures?

A

Underlying genetic/molecular abnormalities leading to connective tissue, muscle, or neurological abnormalities

62
Q

What categories can arthrogryposis be divided into?

A
  • Amyoplasia
  • Distal
  • Syndromic
63
Q

What is amyoplasia?

A

Muscle weakness and multiple severe joint contractures

64
Q

What is distal arthrogryposis?

A

Contractures affecting hands and feet

65
Q

What is syndromic arthrogryposis?

A

Associated with congenital neurological or muscle disease