Arcade of Frohse

Supinator syndrome, also referred to as posterior interosseous syndrome or radial tunnel syndrome , is a rare compression neuropathy of the upper limb affecting the posterior interosseous nerve just near or behind the supinator muscle (Spinner 1968). This nerve is vulnerable to injury at the proximal edge of the superficial belly of the supinator muscle that forms a free, strong, fibrous arch, the arcade of Frohse . At this site, the posterior interosseous nerve may be tethered and entrapped by fibrous bands. 

Spence LD, Adams J, Gibbons D et al (1998) Rice body formation in bicipitoradial bursitis ultrasound, CT, and MRI findings. Skeletal Radiol 2730-32 Spinner M (1968) The arcade of Frohse and its relationship to posterior interosseous nerve paralysis. J Bone Joint Surg Br 50 809-812... 

Figure 107. Common sites of radial nerve entrapment. A, spiral groove B, arcade of Frohse.

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