Extremities Flashcards
What are the abnormalities associated with the Extremities in pregnancies?
9 Limb Deficiency or Amputation Amniotic Band Syndrome Arthrogryposis Clinodactyly Clubfoot Clubhands Ectrodactyly Polydactyly Syndactyly
Limb Deficiency or Amputation
Prevalence: 1 in 20,000 births.
General Principles: In 50% of cases there are transverse reduction deficiencies of one forearm or hand without associated anomalies.
In 50% of cases there are multiple reduction deficiencies and in 25% of these there are additional anomalies of the internal organs or craniofacial structures.
Amputation of the upper extremity is usually an isolated anomaly, whereas amputation of the leg or bilateral amputations of all limbs are usually part of a genetic syndrome.
Isolated amputation of an extremity can be due to amniotic band syndrome, exposure to a teratogen or a vascular accident.
If the defect is unilateral, it may correspond to the femur–fibula–ulna or femur–tibia–radius complex. The former is non-familial, while the second has a strong genetic component.
Phocomelia: Hands and feet are present (may be normal or abnormal), but the intervening arms and legs are absent.
Three syndromes must be considered in the differential diagnosis of phocomelia:
Roberts syndrome: autosomal recessive; tetraphocomelia, bilateral facial cleft, micrognathia, hypertelorism, ear and nose malformations.
Thrombocytopenia with absent radius (TAR) syndrome: autosomal recessive; absence of radius bilaterally associated with thrombocythopenia,
Grebe syndrome: autosomal recessive disorder described in the inbred Indian tribes of Brazil. Characterized by marked hypomelia of upper and lower limbs, increasing in severity from proximal to distal segments. In contrast to Roberts syndrome, the lower limbs are more affected than the upper extremities.
Congenital Short Femur: Classified into five groups:
Simple hypoplasia of the femur
Short femur with angulated shaft
Short femur with coxa vara: this is the most common and is due to deformity of the hip, whereby the angle between the head and the shaft of the femur is reduced to less than 120 degrees.
Absent or defective proximal femur.
Absent or rudimentary femur.
One or both femurs can be affected but the right one is more frequently involved.
Femoral hypoplasia–unusual facies syndrome, which is sporadic, consists of bilateral femoral hypoplasia and facial defects, including short nose with broad tip, long philtrum, micrognathia and cleft palate.
Amniotic Band Syndrome
Prevalence: 1 in 1,200 births.
Ultrasound: Spectrum of features involving extremities, craniofacial region and trunk, which may be isolated or appear in combination. Demonstration of bands in not necessary for the diagnosis of amniotic band syndrome.
Extremities: absent digits or portions of limbs, swollen distal arm or leg resulting from constrictive amniotic bands.
Craniofacial region: facial cleft, asymmetric microphthalmia, severe nasal deformity, encephalocele.
Trunk: severe spinal deformities, large abdominal wall defects with herniated intestine. The most extreme manifestation is body stalk anomaly.
Assoc abnorm: The incidence of chromosomal abnormalities or genetic syndromes is not increased.
Follow up: Ultrasound scans every 2-3 weeks to assess the evolving consequences of the bands.
Prognosis: Prognosis and treatment depends on the nature of amniotic band syndrome and the severity of deformation. Facial deformities often require extensive reconstructive procedures.
Body stalk anomaly is lethal.
Recurrence: No increased risk of recurrence.
Arthrogryposis
Prevalence: 1 in 3,000 births.
Ultrasound: Malposition of the limbs and limited fetal movements, resulting from contractures in ≥2 joints.
Onset of arthrogryposis varies: from 12 to 30 weeks’ gestation.
The condition is commonly associated with polyhydramnios (>25 weeks’ gestation), narrow chest, micrognathia and nuchal edema (or increased nuchal translucency at 11-13 weeks).
Fixed abnormal contractures of muscles can be:
Regional: only the lower or upper limbs are affected. If the lower region is affected, the legs are hyperextended and crossed. If the upper region is affected, the arms are flexed lying on each side of the thorax.
Generalized: all muscles are affected as in fetal akinesia deformation sequence.
Assoc abnorm: Chromosomal abnormalities: a few cases have trisomy 8 or 18.
More than 150 genetic syndromes are associated with arthrogryposis. The most common are:
Fetal akinesia deformation sequence: group of abnormalities of different causes characterized by decreased fetal movements, multiple joint contractures, fetal growth restriction, facial anomalies, pulmonary hypoplasia and occasionally hydrops.
Cerebro-oculo-facio-skeletal syndrome: autosomal recessive; severely reduced muscle tone, distinctive facial features (low-set ears, microphthalmia, micrognathia) and abnormalities of the skull, limbs, heart, and kidneys.
Neu-Laxova syndrome: autosomal recessive; hypertelorism, microcephaly, agenesis of corpus calosum, contractures in the upper and lower limbs, fetal growth restriction.
Multiple pterygium syndrome: autosomal recessive; cystic hygromas, contractures in all joints, microcephaly and micrognathia.
Follow up: Ultrasound scans every 2-3 weeks to monitor growth, movements in all joints and amniotic fluid volume. Amniodrainage may be necessary if there is polyhydramnios and cervical shortening.
Prognosis: If multiple organs are affected there is high mortality within the first months of life.
If only limbs are affected, surgery and physiotherapy aim to achieve the maximum function for each involved joint.
Recurrence: Depends on the underlying condition.
Distal arthrogryposis: 50%.
Clinodactyly
Prevalence: 1 in 100 births.
Ultrasound: Medial deviation or radial curving of the finger at the distal interphalangeal joint usually affecting the fifth finger.
Assoc abnorm: Chromosomal abnormalities: bilateral clinodactyly is found in 60% of newborns with trisomy 21.
The condition is usually isolated.
Follow up: Follow-up should be standard.
Prognosis: Isolated cases: good prognosis. No need for postnatal surgery.
Recurrence: Isolated familial: 50%.
Part of trisomy 21: 1%
Clubfoot
Prevalence: 1 in 1,000 births.
Bilateral in 50% of cases.
Ultrasound: Demonstration that the sole of the foot is not perpendicular to the lower leg bones.
Assoc abnorm: In >50% of cases the condition is isolated.
Chromosomal abnormalities: common finding in trisomies 18 and 13.
Commonly associated with prolonged oligohydramnios, brain abnormalities, spina bifida, skeletal and neuromuscular disorders.
More than 250 genetic syndromes include clubfoot as one component.
Follow up: Isolated: standard follow-up.
Prognosis: Isolated: good prognosis.
In 90% of cases good long-term function is achieved by manipulation and serial application of casts, supported by limited operative intervention.
Surgery is necessary in about 10% of cases and in one third more than one operation is needed.
Recurrence: One sibling with clubfoot: 3%.
Parent and one child with clubfoot: 25%.
Clubhands
Prevalence: 1 in 30,000 births.
Bilateral in 50% of cases.
Ultrasound: Clubhand deformities are subdivided into radial and ulnar:
Radial clubhand: radial aplasia, acute radial deviation of the hand and absent or hypoplastic thumb.
Ulnar clubhand: ranges from mild deviation of the hand on the ulnar side of the forearm to complete absence of the ulna.
Assoc abnorm: Ulnar clubhand is usually an isolated anomaly, whereas, radial clubhand is frequently syndromatic:
Trisomy 18: radial clabhand is a common finding in this chromosomal abnormality.
Thrombocytopenia - absent radius (TAR) syndrome: radial aplasia, thumb present, heart defects, micrognathia.
Holt - Oram syndrome: radial aplasia, syndactyly, heart defects.
Roberts syndrome: radial aplasia, phocomelia, facial cleft, heart defects.
VACTER association: radial aplasia or hypoplasia, vertebral abnormalities, ventricular septal defect, tracheoesophageal fistula, anal atresia, renal defects, and single umbilical artery.
Follow up: Follow-up scans every 4 weeks.
In families with history of TAR syndrome: cordocentesis for diagnosis of hematologic abnormalities.
Prognosis: Depends on the associated condition.
Surgical treatment and physiotherapy aim to improve mobility, strength, and stability of the forearm and wrist.
Recurrence: Part of trisomy 18: 1%.
Part of genetic syndromes: 25% or 50%.
Ectrodactyly
Prevalence: 1 in 20,000 births.
Ultrasound: Spectrum of hand and foot defects with missing digits, median cleft and fusion of the remaining digits resulting in clawlike extremities.
Assoc abnorm: Chromosomal abnormalities: found in trisomy 18.
High incidence of genetic syndromes. The most common are:
Roberts syndrome: autosomal recessive; ectrodactyly, phocomelia, facial cleft.
Ectrodactyly - ectodermal dysplasia (EEC): autosomal dominant; deferomities of all four extremities but more severe in the hands, and ectodermal defects (dry skin, sparse hair, dental defects and defects of the tear ducts).
Nager syndrome: autosomal dominant but in most cases de novo mutations; ectrodactyly, micrognathia, external ear anomalies.
Split hand and foot malformation: ectrodactyly presenting as ‘lobster claw’ anomaly.
Follow up: Standard follow-up.
Consultation by a clinical geneticist.
Prognosis: Isolated: good prognosis.
Surgical treatment and physiotherapy reduce functional impairment of the hands.
Recurrence: Isolated familial: 50%.
Polydactyly
Prevalence: 1 in 100 births in Blacks and 1 in 700 births in Whites.
More common in males than in females: 2 to 1.
Ultrasound: More than 5 digits with or without bony phalanx in the hand or foot.
There are 2 types of polydactyly:
Postaxial (more common): sixth digit is on the ulnar or fibular side, after the fifth digit.
Preaxial (rare): sixth digit is on the radial or tibial side, before the thumb or toe.
Assoc abnorm: Chromosomal abnormalities: found in 75% of fetuses with trisomy 13.
In most cases it is an isolated finding, with an autosomal dominant mode of inheritance. In some cases there is an association with genetic syndromes:
Meckel - Gruber syndrome: autosomal recessive; polydactyly, polycystic kidneys, occipital cephalocele.
Bardet - Biedl syndrome: autosomal recessive; postaxial polydactyly, enlarged hyperechogenic kidneys. Postnatally: obesity, retinopathy, hypogonadism, neurological disorders.
Short - rib polydactyly syndrome: autosomal recessive; short limbs, hypoplastic thorax, polydactyly, heart and brain defects, polycystic kidneys.
Ellis – van Creveld syndrome: autosomal recessive; short limbs, postaxial polydactyly, narrow chest, heart defects.
Follow up: In isolated cases, follow-up should be standard.
Prognosis: Isolated cases: good prognosis.
Recurrence: Isolated familial: 50%.
Part of trisomy 13: 1%.
Part of autosomal recessive syndromes: 25%.
Syndactyly
Prevalence: 1 in 3,000 births.
Ultrasound: Two or more digits (bone or soft tissue) are fused together.
Assoc abnorm: Chromosomal abnormalities: common finding in triploidy.
In most cases it is an isolated finding, but there is a common association with genetic syndromes:
Apert syndrome: autosomal dominant; brachysyndactyly of hands and feet, craniosynostosis, hypertelorism, heart defects.
Carpenter syndrome: autosomal recessive; polysyndactyly, craniosynostosis.
Fraser syndrome: autosomal recessive; microphthalmia, facial cleft, tracheal atresia, bilateral renal agenesis, heart defects, syndactyly or polydactyly.
Follow up: Follow-up should be standard.
Prognosis: Isolated cases: good prognosis.
Recurrence: Isolated familial polysyndactyly: 50%.
Part of Apert syndrome: 50%.
Part of Carpenter and Fraser syndrome: 25%.
Part of triploidy: no increased risk.
