Semin Musculoskelet Radiol 2018; 22(03): 275-285
DOI: 10.1055/s-0038-1641575
Review Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Accessory Muscles of the Extremities

Filip M. Vanhoenacker
1   Department of Radiology, Antwerp University Hospital and Antwerp University, Edegem, Belgium
2   Department of Radiology, AZ Sint-Maarten, Duffel-Mechelen, Belgium
3   Department of Radiology and Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
,
Julie Desimpel
1   Department of Radiology, Antwerp University Hospital and Antwerp University, Edegem, Belgium
2   Department of Radiology, AZ Sint-Maarten, Duffel-Mechelen, Belgium
,
Marc Mespreuve
2   Department of Radiology, AZ Sint-Maarten, Duffel-Mechelen, Belgium
3   Department of Radiology and Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
,
Alberto Tagliafico
4   Department of Health Sciences, Genoa University, Genoa, Italy
› Author Affiliations
Further Information

Publication History

Publication Date:
23 May 2018 (online)

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Abstract

Accessory muscles and variations are not uncommon at the upper and lower extremity. They are often overlooked because they are asymptomatic and present as incidental findings on imaging. However, they may present as a soft tissue swelling, thereby mimicking soft tissue tumors. Other symptoms are attributed to impingement on neurovascular structures and to exercise-related pain. Thorough knowledge of the anatomy, systematic imaging analysis, and the awareness of it are the clues to correct identification. On ultrasound, accessory muscles have a similar echotexture as other muscles, whereas the signal intensity on magnetic resonance imaging (MRI) is similar to muscle. Because of the intrinsic contrast with the adjacent intermuscular fat, accessory muscles are best depicted on MRI without fat suppression. This article provides a short overview of the anatomy of most prevalent accessory muscles of the upper and lower limb and its potential pathogenic nature.