osteogenesis imperfecta Flashcards
osteogenesis imperfecta is colloquially known as
brittle bone disease
osteogenesis imperfecta is a congenital disorder what does this mean
it is present at birth
what causes osteogenesis imperfecta
defect in the maturation and organisation of type 1 collagen which is the major organic component of bone
nearly all cases are inherited in what way
autosomal dominantly
presentation of autosomal dominant inheritance
- history of frequent childhood fragility fractures
- short stature and deformities
- blue sclerae
- loss of hearing
why is sclera blue
the sclera is thinner because of the lack of connective tissue so the blood vessels underneath are visible
why does it cause loss of hearing
due to involvement of the bones of the inner ear
what is the exception to the inheritance rule
rarely some cases are inherited autosomally recessively and they end in peri-natal death or spinal deformity
what is the bone like in OI
the bone is thin with thin cortices and osteopenia, the multiple fractures have abundant but poor calluses so bone never ever heals properly
why do you need to tread carefully in OI
it is usually diagnosed as child abuse which is traumatic for all involved
what should you think about in mild forms of disease
X-rays may be remarkably normal, but person will have a history of multiple low frequency fractures
treatment of OI
biphosphonates, fractures treated with splintage, traction or surgical stabilisation and deformities may need multiple osteotomies with intra-medullary fstabilisation
