Frohse's arcade is not the exclusive compression site of the radial nerve in its tunnel

Abstract

Anatomic studies have revealed a variable rate of occurrence of a tendinous AF, which range from 30 to 80% (87% in our study) according to authors. It is reported to be a predisposing factor to the development of chronic entrapment neuropathy of the DBRN, especially if it is thick and provides a narrow opening for passage of the DBRN. The tendinous consistency of the supinator arch is believed to develop in adults, in response to repeated rotary movements of the forearm. Repetitive pronation and supination of the forearm induces compression of the radial nerve and its branches between two inextensible structures. The fibrous AF and the proximal end of the radius (radial head and radial tubercle). This condition is aggravated by the supinator muscle repeated activity. Repetitive compression might then promote histological changes in radial tunnel content and progressive development of a local fibrous zone. We also observed that the radial nerve supply to ECRB could be entrapped between the superolateral aspect of the ECRB and the superior edge of the supinator muscle.

Radial tunnel syndrome: results of surgical decompression by a postero-lateral approach

“…It is important to consider the variability of the pattern of radial nerve innervation at the distal level, as we have been able to observe in our study [1,11,12]. This explains the three pareses of the common finger extensors seen in our patients caused by excessive distal dissections.…”

“…There are no alterations in the normal static neurophysiological state with a normal nerve conduction velocity [3,5,6,9,10,[13][14][15]. This is all due to the fact that the PIN is compressed intermittently by the muscles that form the radial tunnel, causing pain [6,11,12,14].…”

“…It is characterised by a dynamic compression of the PIN brought about by repetitive pronation-supination forearm movements [11,12]. The most frequent causes [3,4,6,7,[13][14][15][16] are: fibrous bands located above the radial head; recurrent radial vessels jumping over the nerve in the area most proximal to the lateral epicondyle, which increase blood flow to the extensor, supinator and brachialis muscles during exercise, compressing the PIN; proximal aponeurotic insertion of the second radial; and the arcade of Frohse, formed by the two muscle bellies of the supinator, which surround the nerve and can also produce compression inside the supinator or at its distal border (Fig.…”

Specific Mechanical Pain Hypersensitivity Over Peripheral Nerve Trunks in Women With Either Unilateral Epicondylalgia or Carpal Tunnel Syndrome

“…Previous studies have supported the involvement of the extensor muscles of the wrist, particularly the extensor carpi radialis brevis muscle, in LE. 21,22,53,54 Clavert et al 15 observed in an anatomical study that the radial nerve may get entrapped in the superolateral aspect of the extensor carpi radialis brevis muscle. Therefore, it is possible that impairments in this muscle can lead to mechanical irritation of the radial nerve.…”

Magnetic resonance imaging of the elbow

“…The most common cause of radial tunnel syndrome is entrapment by the arcade of Frohse, a fibrous arch within the superficial head of the supinator (76,92). Other sites of entrapment include fibrous bands arising between the joint capsule and brachioradialis, vascular arcades of the recurrent radial artery known as the leash of Henry, or under the leading edge of the extensor carpi radialis brevis (76,92,93).…”