|ECR 2011 / C-2085|
|Congenital upper limb malformations : pictorial review|
Imaging findings OR Procedure details
I- Failure of formation
Transverse deficiency (fig 1):
Transverse deficiency may be divided into amelia (absence of arm), hemimelia (absence of forearm), acheiria (absence of hand) and symbrachydactyly. They are commonly sporadic, due to a vascular accident during morphogenesis. They may occur in syndromes such as tetraamelie, Roberts syndrome (facial abnormalities), Hanhart syndrome (hypoglossia-hypodactylia) and toxic embryofoetopathies.
Amniotic band syndrome is a differential diagnosis of transverse deficiency. It represents a disruption or deformation sequence subsequent to annular bands of chorionic tissue encircling the limb. It has a low incidence of associated abnormalities, normal proximal anatomy, and a sporadic occurrence. Clubfoot is the most common associated abnormality. Distal fusion of amputated digits, as in acrosyndactyly, may be present. Radiological findings are characteristic and show amputation below an annular band.
Preaxial deficiency (figs 2 and 3)
It may vary from minor abnormalities of the thenar muscles to complete absence of the preaxial structures (radius, radial carpal bones, and thumb). The most common presentation is a short radius, absence of scaphoid and trapezium, and total absence or hypoplasia of the thumb (ie, radial club hand). Coalition of radial carpal bones, proximal radioulnar synostosis and radial head dislocation may be seen. Preaxial deficiency may occur bilaterally or unilaterally and is often part of a syndrom.
VACTERL (Vertebral abnormalities, Anorectal atresia, Cardiac defects, Tracheo-oesophageal fistula with or without Esophageal atresia, Renal abnormalities, Limb abnormalities)
Fanconi's anemia (aplastic anemia not present at birth)
TAR syndrome (thrombocytopenia- absence of radius)
Holt-Oram syndrome (heart defects, most commonly septal defects)
Nager syndrome (craniofacial malformations)
Baller Gérold syndrome (craniosynostosis)
Okihiro syndrome (eye abnormalities)Trisomy 13 or 18
Main syndromes associated with preaxial deficiency
Postaxial deficiency (fig 4)
It is characterized by ulnar or postaxial digit (IV/V) deficiencies. Humeroradial synostosis, radial head dislocation, carpal or metacarpal (IV-V) coalition and pre-axial digit (I/II) deficiencies may be seen. Most of them show autosomal dominant (AD) patterns of inheritance. Syndromic associations are rare. Postaxial deficiencies usually are unilateral compared to preaxial deficiencies.
Miller syndrome (craniofacial malformations)
Cornelia De Lange syndrome (distinctive facial features and multiple congenital malformations)
FFU syndrome (Femur Fibula Ulna syndrome)
Main syndromes associated with postaxial deficiency
Centroaxial deficiency (fig 5)
It manifests as absence of digits or metacarpals within the central portion of the hand. Carpal coalition, pre- or postaxial syndactyly, surnumerary metacarpal bone may be seen. The radius and ulna are normal. Centroaxial deficiency may be classified as being either typical or atypical. The typical cleft hand is generally bilateral and familial whereas the atypical one is unilateral and spontaneous.
SHFM syndrome (Split Hand Foot Malformation)
EEC syndrome (Ectrodactyly, Ectodermal dysplasia, Clesting syndrome)
EEM syndrome (Ectrodactyly, Ectodermal dysplasia, Macular dystrophy)
Main syndromes associated with typical central deficiency
Intercalary deficiency (fig 6)
In phocomelia, a functional terminal element is always present. Different types of phocomelia are as follows: those in which the hand attaches to the shoulder (forearm and arm deficient), those in which the forearm attaches to the shoulder (arm deficient) and those in which the hand attaches to the arm (forearm deficient). The arm deficient type is often spontaneous whereas the two others may occur in toxic embryofoetopathy or Roberts syndrome.
II- Failure of differenciation
Humeroradial synostosis (fig 4)
It is often encountered in postaxial deficiency.
Radioulnar synostosis (fig 7)
It is often bilateral and spontaneous. It may also occur in preaxial deficiency and Klinefelter syndrome.
Syndactyly (fig 8)
Syndactyly is classified according to completeness (complete, incomplete) and presence of bony union (simple, complex, complicated). Complicated syndactyly refers to any syndactyly in which more than a simple side-side bony fusion exists. They may be classified in preaxial, postaxial, centroaxial, complete and synpolydactyly.
|Preaxial (I-II)||Preaxial syndromes (Holt Oram, Townes Brocks syndromes...)|
|Centroaxial (III-IV), the most common form||Spontaneous|
|Postaxial (IV-V)||Familial (dominant) or ODD syndrome|
|Complete||Apert syndrome (fig 9)(craniostenosis) and other acrocephalosyndactylies|
|Synpolydactyly (mesoaxial syndactyly with duplication of the fourth digit)||Familial (HOXD13 gene)|
Classification and causes of syndactylies
Apert syndrome is an autosomal dominant disorder. It is the most severe form of acrocephalosyndactyly. The main radiographic sign is a symetrical complete syndactylie of hands and feet (mitten hands and sock feet). It is associated with craniosynostosis.
Preaxial polydactyly (duplicated thumb) is the most common form and the level of duplication is variable. It is commonly spontaneous but syndromes may be associated (fig 10).
Postaxial polydactyly is characterized by fifth digit duplication in hands and/or feet. Two phenotypic varieties have been described. In type A, the extra digit is well formed and articulates with the fifth or an extra metacarpal. A rudimentary extra fifth digit characterizes the type B. Postaxial polydactyly has a strong AD inheritance pattern and is commonly seen in individuals of African descent. It may also be seen in syndromes (fig 11).
Central polydactyly is rare. Complex duplication is also described. Polysyndactyly is an example (fig 12).
Ellis Van Creveld syndrome
Main syndromes associated with polydactyly
It is divided into 5 types (fig 13,14). Brachymesophalangy may be responsible for clinodactyly. Brachydactyly A3 is considered as an anatomic variant. Brachydactyly C (brachymesophalangy of the index, middle and little fingers with shortening of the first metacarpal) may be very heterogeneous:hyperphalangy of the index, anomalous configuration of the index (resulting in its ulnar deflection), short metacarpals, symphalangism and "angel-shaped" phalanges (fig 15) are occasionally present.
Brachydactylies are commonly isolated malformations but they may be part of a complex malformation. The exception is brachydactyly E in which Albright osteodystrophy and Turner syndrome are potential diagnoses (fig 16).
V- Sprengel deformity (fig 17)
It is a failure of the scapula descent from the level of the embryonic limb bud opposite the fifth cervical vertebra to its thoracic position. Hypoplasia of the scapula and associated abnormalities are commonly seen (of the clavicles, ribs, vertebrae and shoulder musculature). The most common associated finding is the omovertebral bone.
VI- Congenital pseudarthrosis of the clavicle (fig 18)
Congenital pseudarthrosis of the clavicle usually occurs on the right side. Radiologic evaluation shows lack of bone continuity in the middle third of the clavicle without evidence of reactive bone.It needs to be distinguish from birth fracture, neurofibromatosis and cleidocraniodysostosis.
VII- Clinodactyly (fig 19)
It denotes a deviation of a finger as a result of an abnormally shaped middle phalanx. It may occur because of a delta phalanx. The latter corresponds to a congenital triangular bone. The classic finding is seen as a bone with a continuous C-shaped physis extending along the length of the shortened side, like a staple.
It is a medical condition involving fixed flexion deformity of the interphalangeal joints.