Cortex - Paediatric orthopaedics 1 Flashcards
Define what osteogenesis imperfecta is
It is a defect of the maturation and organization of type 1 collagen (collagen accounts for the majority of the oganic composition of bone)
Describe the typical presentation of osteogenesis imperfecta
- 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
What is the genetic inheritance for the majority of osteogenesis imperfecta cases ?
Autosomal dominant
What is the treatment of osteogenesis imperfecta?
Fractures tend to heal with poor quality callus so are treated with splintage, traction or surgical stabilization
Define what is meant by the term skeletal dysplasia
- 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
Describe the two main ways in which skeletal dysplasia can present
The short stature can be proportionate or disproportionate
What is the most common type of skeletal dysplasia and describe its inheritance ?
Achondroplasia - can be inherited through an autosomal dominant mutation or 80% of the time due to sporadic mutation
Describe the presentation of achondroplasia
- Results in disproportionately short limbs (compared to spine) with a prominent forehead and widened nose.
- Joints are lax and mental development is normal.
Describe in general terms what connective tissue disorders
They are due to genetic disorders of collagen synthesis (mainly type 1 which is found in bone, tendon and ligaments)
What are the different connective tissue disorders ?
- Generalised (Familial) Joint Laxity
- Marfan’s syndrome
- Ehlers‐Danlos syndrome
- Down syndrome
What is the difference between osteogenesis imperfecta and connective tissue disorders ?
- Both are disorders of type 1 collagen but ostoegenesis imperfecta predominatley affects bones
- Whereas the connective tissue disorders affect soft tissues more than bone.
What is generalised (familial) joint laxity ?
- 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
What is marfans syndrome and what causes it ?
A connective tissue disorder due to mutation of the fillibrin gene (FBN1)
Describe the typical presentation of marfans syndrome
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.
What is often a cause of death in patients with marfans syndrome ?
Cardiac abnoramilities e.g. aortic aneurysm and cardiac valve incompetence
What is Ehlers‐Danlos syndrome?
Condition inherited by autosomal dominant mutation which results in abnormal elastin and collagen formation. This causes profound joint hypermobility
What are the features of Ehlers‐Danlos syndrome?
- Profound joint hypermobility and instability,
- Elastic fragile skin with ease of bruising
- Scoliosis.
What are the MSK manifestations of downs syndrome ?
Short stature and joint laxity with possible recurrent dislocation (especially patella)
In general terms what are muscular dystrophies ?
Usually X‐linked recessive hereditary disorders (only affects boys) resulting in progressive muscle weakness and wasting.
What are the 2 main muscular dystrophies ?
Duchennes and Beckers
What causes duchennes muscular dystrophy ?
A defect in the dystrophin gene
Describe the presentation of duchennes muscular dystrophy
- 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
How is duchennes muscular dystrophy diagnosed ?
By raised serum CK and abnormalities on muscle biopsy
What is the management of duchennes muscular dystrophy ?
Physiotherapy, splintage and deformity correction to try to prolong mobility for as long as possible
What is beckers muscular dystrophy ?
Basically justa mild form of duchennes muscular dystrophy where boys are able to walk for longer and may survive up until 30s or 40s
What is the characteristic sign seen when kids are starting to walk who have duchennes muscular dystrophy?
Gowers sign
