Atlanta Case 15|
What are the major orthopaedic concerns with this condition?
This, of course, is Down's syndrome or Trisomy 21 ( 95% trisomy 21; 2%
mosaics and 3% translocations). Incidence about 1 in 600 live births falling
to 1 in 250 in mothers over 35 years.
There are several orthopaedic problems possible in these children.
1. Atlanto-axial instability. Some 10% show increased atlanta -dens interval
( ADI). They may have Occiput -C1 instability , odontoid hypoplasia, cervical
spondylolisthesis and hypermobility of their mid cervical spine.
2. Scoliosis. Occurs in about half the patients and is of an idiopathic nature
3. Hip joint laxity. The generalized ligamentous laxity in these patients
probably predisposes them to hip instability and to recurrent dislocation
even after open reduction and femoral/pelvic osteotomies. Acetabular dysplasia
is very common and can occur into adulthood.
4. Slipped upper femoral epiphyses. The slips are easily missed in this
population and therefore are diagnosed later and may be more severe with a
higher incidence of AVN. Some have concommitant hypothroidism which increases
the risk of slip.
5. Lax ligaments possibly contribute to their genu valgum and patella
dislocations. Again recurrences are common despite surgical correction.
6. Several other problems can occur including hallux valgus deformity in these
flexible flat feet, a polyarticular arthropathy resembling rheumatoid and
leukemia in about 1% which may first present to the orthopaedic clinic. They
also are infection prone.
It's little wonder that these gentle children can terrorise the most
hardened orthopaedic surgeons with their deguiling smile! This is Down's
syndrome or Trisomy 21 ( 95% trisomy 21; 2% mosaics and 3% translocations).
Incidence about 1 in 600 live births falling to 1 in 250 in mothers over 35