Skeletal Dysplasia (Osteochondrodysplasias)
Intro
heterogeneous group of heritable disorders characterised by abnormalities of cart + bone growth, resulting in abnormal shape + size of the skeleton + disproportion of long bones, spine + head
Achondroplasia
Osteogenesis Imperfecta (Brittle Bone Disease)
Thanatophoric Dysplasia
AD inheritance, but 50% sporadic
short stature
short limbs
large head
frontal bossing
depression of nasal bridge
short broad hands
marked lumbar lordosis develops
hydrocephalus sometimes occurs
often no family hx
Group of disorders of collagen metabolism
Bone fragility, bowing, #s
Type 1
most common
AD
fractures during childhood
blue sclerae
some develop hearing loss
tx = bisphosphonates to reduce # incidence, splinting after #s to minimise joint deformity
Type 2
prognosis variable
severe, lethal
multiple #s present before birth
often stillborn
inheritance mostly AD or sporadic, paternal mosaicism has been noted too
in other types scleral discolouration may be minimal
may be wormian bones in skull (extra bones within skull sutures)
results in stillborn
large head, extremely short limbs, small chest
sporadic
may be identified on antenatal US
Cleidocranial dysostosis
AD
absence of part of/all of clavs
delay in ant fontanelle closure + ossification of skull
child can bring shoulders together in front of chest to touch each other
short stature usually present
intelligence normal
Arthrogryposis
heterogeneous group of congenital disorders
stiffness + contracture of joints
cause usually unknown
a/w oligohydramnios, widespread congenital abnormalities + chromo disorders
usually sporadic
flexion contractures in knees, elbows, wrists
dislocation of hips + other joints
talipes equinovarus
scoliosis
thin skin
reduced subcut tissue
marked muscle atrophy atrophy affected joints
intelligence unaffected
management
physio
splints
plaster casts
surgery
walking impaired in severe forms
Osteopetrosis (marble bone disease)
rare, severe
bones are dense but brittle
AR
FTT
recurrent infection
hypocalcaemia
anaemia
thrombocytopenia
poor prognosis
BM transplant can be curative
less severe AD form can present in childhood with #s
Marfan syndrome
AD
tall stature
long thin digits (arachnodactyly)
hyperextensible joints
high arched palate
upward dislocation of lenses
severe myopia
great distance between pubis + sole than pubis + crown
arm span > height
chest wall deformities
scoliosis
Degeneration of media of blood vessel walls
dilated incompetent aortic root
valvular incompetence (mitral valve prolapse + regurg)
aortic aneurysms may dissect/rupture
ECHO monitoring needed