Transcript Limb Anomalies

Prof. mamoun Kremli
DR: Gehan Mohamed
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Recognize some Limb Anomalies
 Amelia, Meromelia, Hemimelia
 Polydactyly
 Syndactyly
 Amniotic band syndrome
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Discuss Etiology
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Melia: from Greek: ”Limb”
Amelia: GK, A: Lack of..
Meromelia: Gk, meros: “part”: lack of
part
 Phocomelia:Gk, Phoco: “Seal”: like limb
of Seal
 Hemimelia: GK, Hemi: “Half”: lack of half
of limb
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Limbs arise from small limb buds
 Upper limb bud appear after 26 days
 Lower limb bud appear after 28 days.
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Somatic lateral mesoderm →limb buds
 (mesodermal core + ectodermal cap) →
 elongated & fragmented → 3 portions
Wk 6
Terminal portions of limb buds form
hand & foot plates
 Digital rays in distal ends form fingers &
toes (wk 8) (apoptosis of tissues in
between)
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Limb anomalies Are
-prevented: Amelia
-Interrupted: Meromelia. Phocomelia,
Hemimelia
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Very early in the developing embryo:
 Between 24-36 days following fertilization
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Absence of one or more limbs
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Absence of one or more limbs
A.
Environmental Factors
1. Teratogenic drugs
▪ e.g. Thalidiomide (was introduced as analgesic
drug )
2. Maternal Factors - Diabetes mellitus
3. Vascular accidents in uterus
B.
Genetics – 20%
1. Mutations in genes
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Partial absence of a limb
or limbs
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Extremities resemble those of a seal.
Typically, hands and feet are present
(may be normal or abnormal), but the
intervening arms and legs are absent
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Poly: many, dactyl: digit (finger/toe)
Presence of more than normal number
of fingers or toes
 Rudimentary finger or toe, or
 Fully developed extra digit(s)
www.similima.com
18
Most common congenital malformation
of limbs
 Incidence: 1 in 2000-3000
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10-40 % are familial
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Non hereditary non syndromic
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Few reports association with maternal
smoking

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www.similima.com
This type of mild
syndactyly is found
occasionally on the
physical
examination.
This is usually an
isolated finding, and
in this location, has
no impact on
function.
23
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Hand with transverse deficiency at the
metacarpal level.
Watson S Arch Dis Child 2000;83:10-17
Copyright © BMJ Publishing Group Ltd & Royal College of Paediatrics and Child Health. All rights reserved.
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At a different plane
At 90o to other fingers
Opposition motion
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50% of hand function
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Pollicization of the index finger to make a thumb
Father
Child after surgery
Watson S Arch Dis Child 2000;83:10-17
Copyright © BMJ Publishing Group Ltd & Royal College of Paediatrics and Child Health. All rights reserved.

Hand with thumb and aplastic fingers.
Watson S Arch Dis Child 2000;83:10-17
Copyright © BMJ Publishing Group Ltd & Royal College of Paediatrics and Child Health. All rights reserved.

The constriction of appendages by amniotic
bands may result in:
 Restrictions of the growth around the digits, arms
and legs
 Constriction rings around the digits, arms and legs
 the bands will partially constrict the blood flow in the
affected appendage causing a deep groove in the baby's
skin
 Swelling of the extremities distal to the point of
constriction (congenital lymphedema)
 Amputation of digits, arms and legs (congenital
amputation)
Before surgery
After surgery
Partial fibular
hemimelia
 Short leg
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Which is worse?
Why?
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Which is worse?
Why?
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Which bone is more
important for knee and
ankle joint surfaces?
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Many congenital anomalies
Nomenclature:
 Amelia
 Phocomelia, meromelia
 Hemimelia
 Polydatyly, Syndactyly
 Amniotic band syndrome
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Importance of thumb
 50% of hand function
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Tibial hemimelia Vs. Fibular hemimelia
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Causes od anomalies:
 Teratogenic Drugs
 Uterine problems
▪ Blood supply (vascular accidents)
 Maternal factors
▪ Disease: Diabetes
▪ Smoking, Alcohol
 Hereditary