Learning objectives
The aim of this poster is to highlight through relevant diagrams and selected x-rays the incidence,
topography and morphology of the most frequent accessory bones of the limbs found in everyday practice.
Supernumerary bones of both the upper and lower limb are reviewed,
with special focus on the Os Trigonum Syndrome,
a clinical entity caused by the presence of an accessory bone in the ankle.
Accessory ossicles must be differentiated from small fracture fragments thus knowing the morphology and topography of these bones is important...
Background
Supernumerary bones are a relative frequent finding in plain x-rays .
They are of forensic importance in that,
when seen in radiograms,
they may be mistaken for fractures.
Knowing the topography and morphology of these bones is important both for the trauma radiologist and for students and radiology residents since most of these bones come as incidental findings.
Many bones develop from several centers of ossification,
eventually the separate parts normally merge.
At times,
one of these centers fails to fuse with the main bone...
Findings and procedure details
UPPER LIMB
Wrist and Hand: Carpals,
Metacarpals and Phalanges
The number of carpal bones is frequently and variably increased.
Over 20 accessory ossicles have been described.
These usually occur because of failure of fusion of ossification centers.
The os centrale (1) is an additional bone located on the dorsal aspect between the scaphoid,
capitate,
and trapezoid.
It is formed when a small cartilagenous nodule fails to fuse with the scaphoid,
and may be doubled.
The os vesalianum carpi (2) is a small bone at the...
Conclusion
Accessory ossicles must be differentiated from small fracture fragments thus knowing the morphology and topography of these bones is important in interpreting trauma x-rays.
References
1.
Accessory Ossicles and Sesamoid Bones: Spectrum of Pathology and Imaging Evaluation Dr.
Kalantari,
Dr.
Seeger,
Dr.
Chow,
Dr.
Motamedi Appl Radiol.2007;36(10):28-37.
2.
The Accessory Ossicles of the Foot and Ankle; a diagnostic Pitfall in Emergency Department in Context of Foot and Ankle Trauma,
Özkan Köse,
JAEM,
2012,
vol 11,
issue 2: 116-114.
3.
Koehler/Zimmer's Borderlands of Normal and Early Pathological Findings in Skeletal Radiography,
Thieme 2002.
4.
Illustrated Encyclopedia of Human Anatomic Variation,
Anatomy Atlases 2006.
5.
Morrey's the elbow and its disorders,
Saunders,...