CASE 10476 Published on 22.11.2012

Brachydactyly

Section

Musculoskeletal system

Case Type

Clinical Cases

Authors

Huyskens J 1, Vanhoenacker FM1,2,3 , Boutry N4 , Parizel PM1 , Van der Aa N 1

(1) University Hospital Antwerp, Department of Radiology, University Hospital Antwerp; Wilrijkstraat, 10 2650 Antwerp (Edegem), Belgium; Email:filip.vanhoenacker@telenet.be
(2)University of Ghent, Faculty of Medecine and Health-services, Belgium
(3)General Hospital Sint-Maarten, Duffel-Mechelen, Belgium
(4)Hôpital Jeanne de Flandre, Service de Radiopédiatrie, CHRU de Lille, France
Patient

3 years, female

Categories
Area of Interest Bones ; Imaging Technique Conventional radiography
Clinical History
A 3-year-old girl was referred for mental retardation with known consanguinity. She was treated for a ventricular septal defect. Clinical examination revealed crooked little fingers and short index fingers. For further evaluation of a skeletal dysplasia, conventional radiographs of the pelvis, thoracolumbar spine, hands, and feet were performed.
Imaging Findings
Anteroposterior radiographs of both hands showed an absence of the intermediary phalanx of the index finger on both sides (bold arrows Fig. 1, 2). There was also shortening and slanting of the distal articular surface of the intermediary phalanx of the fifth finger with a subsequent radial deflection, more pronounced on the left side (arrows Fig. 1, 2).
Dorsoplantar radiographs of both feet revealed absence of the intermediary phalanges of the second to fifth toe on both sides (bold arrows Fig. 3, 4).
Pelvic and thoracolumbar radiographs were normal.
Discussion
Brachydactyly is a descriptive term for ‘short digits’. It may affect the metacarpals, phalanges, metatarsals or all. Shortening may be due to an abnormal shape, absence or fusion of bones. Fusion of the phalanges is also known as symphalangism. If the deformity leads to a deflection of the finger, it is called clinodactyly.
It occurs either as an isolated form or as a part of a complex syndrome.
In the isolated form, it is generally inherited in an autosomal dominant way with a variable penetrance and severity. The deformity is classified according to Bell and has been further elaborated by Temtamy and McKusik.
The different types are listed in Table 1 and Figure 4. Most of the types are rare, with the exception of type A3 and type D, having a prevalence of about 2%.
Besides the more common clinodactyly, as in type A3, our patient presented also with an absence of the middle phalanges of both index fingers as well as in the second to fourth toe on both sides. This is in line with type A4, also known as brachymesophalangy II and V or Temtamy type. This type is a rare occurrence, only a few are reported in literature, mostly in family studies. The absence of the intermediary phalanges of the toes is not a constant feature of this type.
Sometimes, the fourth digit of the hand can also be affected, in which it has an abnormal shape with radial deviation, leading to a crooked ring finger. When a patient presents with a crooked finger, the radiologist should carefully scrutinize the shape, absence or fusion of all bones within the hand, in order to differentiate isolated (non-congenital) forms of clinodactyly from complex inherited forms which need further genetic counselling.
Differential Diagnosis List
Brachydactyly type A4 (Bell’s classification), brachymesophalangy II-V, Temtamy type brachydactyly.
Crooked fifth finger
Clinodactyly
Final Diagnosis
Brachydactyly type A4 (Bell’s classification), brachymesophalangy II-V, Temtamy type brachydactyly.
Case information
URL: https://www.eurorad.org/case/10476
DOI: 10.1594/EURORAD/CASE.10476
ISSN: 1563-4086