Cortex - Paediatric orthopaedics 1

Question 1

Define what osteogenesis imperfecta is

Answer 1

It is a defect of the maturation and organization of type 1 collagen (collagen accounts for the majority of the oganic composition of bone)

Question 2

Describe the typical presentation of osteogenesis imperfecta

Answer 2

• Multiple fragility fractures of childhood (which can be mistaken for NAI - i.e. child abuse)
• Short stature with multiple deformities
• Blue sclerae
• Loss of hearing

Question 3

What is the genetic inheritance for the majority of osteogenesis imperfecta cases ?

Answer 3

Autosomal dominant

Question 4

What is the treatment of osteogenesis imperfecta?

Answer 4

Fractures tend to heal with poor quality callus so are treated with splintage, traction or surgical stabilization

Question 5

Define what is meant by the term skeletal dysplasia

Answer 5

• It is the term used to describe short stature (dwarfism no longer used)
• There is abnormal development of bone and connective tissue
• There is > 300 types of skeletal dysplasias

Question 6

Describe the two main ways in which skeletal dysplasia can present

Answer 6

The short stature can be proportionate or disproportionate

Question 7

What is the most common type of skeletal dysplasia and describe its inheritance ?

Answer 7

Achondroplasia - can be inherited through an autosomal dominant mutation or 80% of the time due to sporadic mutation

Question 8

Describe the presentation of achondroplasia

Answer 8

• Results in disproportionately short limbs (compared to spine) with a prominent forehead and widened nose.
• Joints are lax and mental development is normal.

Question 9

Describe in general terms what connective tissue disorders

Answer 9

They are due to genetic disorders of collagen synthesis (mainly type 1 which is found in bone, tendon and ligaments)

Question 10

What are the different connective tissue disorders ?

Answer 10

• Generalised (Familial) Joint Laxity
• Marfan’s syndrome
• Ehlers‐Danlos syndrome
• Down syndrome

Question 11

What is the difference between osteogenesis imperfecta and connective tissue disorders ?

Answer 11

• Both are disorders of type 1 collagen but ostoegenesis imperfecta predominatley affects bones
• Whereas the connective tissue disorders affect soft tissues more than bone.

Question 12

What is generalised (familial) joint laxity ?

Answer 12

• Essentially it is joint hypermobility usually runs in families and is inherited in a dominant manner ‘‘described as double jointed’’
• More prone to soft tissue injuries due to ligamentous laxity and dislocations esp shoulder and patellar

Question 13

What is marfans syndrome and what causes it ?

Answer 13

A connective tissue disorder due to mutation of the fillibrin gene (FBN1)

Question 14

Describe the typical presentation of marfans syndrome

Answer 14

Tall stature with disproportionately long limbs and ligamentous laxity.

Features:

• High arched palate
• Scoliosis
• Flattening of the chest (pectus excavatum)
• Eye problems (lens dislocation, retinal detachment)
• Aortic aneurysm and cardiac valve incompetence.

Question 15

What is often a cause of death in patients with marfans syndrome ?

Answer 15

Cardiac abnoramilities e.g. aortic aneurysm and cardiac valve incompetence

Question 16

What is Ehlers‐Danlos syndrome?

Answer 16

Condition inherited by autosomal dominant mutation which results in abnormal elastin and collagen formation. This causes profound joint hypermobility

Question 17

What are the features of Ehlers‐Danlos syndrome?

Answer 17

• Profound joint hypermobility and instability,
• Elastic fragile skin with ease of bruising
• Scoliosis.

Question 18

What are the MSK manifestations of downs syndrome ?

Answer 18

Short stature and joint laxity with possible recurrent dislocation (especially patella)

Question 19

In general terms what are muscular dystrophies ?

Answer 19

Usually X‐linked recessive hereditary disorders (only affects boys) resulting in progressive muscle weakness and wasting.

Question 20

What are the 2 main muscular dystrophies ?

Answer 20

Duchennes and Beckers

Question 21

What causes duchennes muscular dystrophy ?

Answer 21

A defect in the dystrophin gene

Question 22

Describe the presentation of duchennes muscular dystrophy

Answer 22

• Muscle weakness which is notcied when the kid starts to walk with difficulty standing and going up stairs
• Progressive muscle weakness occurs resulting in not being able to walk by about 10, they then develop cardiac and resp failure which typically leads to death roughly in there 20s

Question 23

How is duchennes muscular dystrophy diagnosed ?

Answer 23

By raised serum CK and abnormalities on muscle biopsy

Question 24

What is the management of duchennes muscular dystrophy ?

Answer 24

Physiotherapy, splintage and deformity correction to try to prolong mobility for as long as possible

Question 25

What is beckers muscular dystrophy ?

Answer 25

Basically justa mild form of duchennes muscular dystrophy where boys are able to walk for longer and may survive up until 30s or 40s

Question 26

What is the characteristic sign seen when kids are starting to walk who have duchennes muscular dystrophy?

Answer 26

Gowers sign