PHYSICAL CONSTRAINT FROM MOVEMENT
Arthrogryposis
multiplex congenita due to physical constraint occurs when the capacity
of the uterine cavity is small and asymmetric or when the fetus is affected
by cutaneous bands that restrict limb movements. The
capacity of the uterus may be restricted by oligohydramnios, anatomic
malformations, amniotic bands, or uterine tumors. Thick cutaneous bands
that restrict fetal joint movements occur in Escobar syndrome.
Oligohydramnios
sequence
Oligohydramnios
is the most frequent cause of arthrogryposis multiplex due to physical
constraint. A reduced uterine capacity may produces arthogryposis (click
in figure) but in addition places the fetus at risk for multiple
anomalies.
The
constellation of findings that occur as the result of decreased amniotic
fluid is called oligohydramnios sequence. The characteristic features
of oligohydramnios sequence are wrinkled skin; skin folds that extend
from the inner canthus to the upper cheek; squashed nose; large, low-set
and posteriorly rotated ears; short neck; and large wrinkled hands. Neonates
may also show scars at skin areas of maximal pressure (Figure 156.1 A).
Arthrogryposis usually involves the knees, feet, wrist and elbow (Figure
156.1 B). The most frequent causes of oligohydramnios are placental insufficiency
and premature rupture of membranes. Bilateral renal agenesis is a rare
but severe cause of oligohydramnios often associated with arthrogryposis.
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B |
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Figure 156.1.— Arthrogryposis due to
physical constrain. [A] scar; [B] arthrogryposis of the wrist.
Escobar
syndrome
Escobar
syndrome or multiple pterygia syndrome is characterized by thick skin
folds that produce an unusual appearance and keep the joints in a fixed
position. The skin folds are usually in the neck, axilla, antecubital,
popliteal, and digital areas. The thick skin folds reduce joint motility
in utero and lead to arthrogryposis multiplex congenita. Arthrogryposis
is especially marked in the hands. Intelligence is normal. Scoliosis often
develops by five years of age. Escobar syndrome is an autosomal recessive
condition. Surgical treatment of the pterygium may be necessary.
NEUROLOGICAL
ABNORMALITIES
Neurological
disorders should be suspected in any neonate without signs that suggest
a cartilaginous abnormality, oligohydramnios sequence, or Escobar syndrome.
Neurological abnormalities can be classified based on the region of the
nervous system most affected.
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