Posterior Interosseous Nerve

Lateral (wrist extensor) and supinator Supplied by the radial and the posterior interosseous nerve, this group consists of the supinator, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum communis, and the extensor carpi ulnaris. 

Chien AJ, Jamadar DA, Jacobson JA et al (2003) Sonography and MR imaging of posterior interosseous nerve syndrome with surgical correlation. AJR Am J Roentgenol 181 219-221... 

Peer S, Bodner G, Meirer R et al (2001) Examination of postoperative peripheral nerve lesions with high-resolution sonography. AJR Am J Roentgenol 177 415-419 Sener E, Takka S, Cila E (1998) Supracondylar process syndrome. Arch Orthop Trauma Surg 117 418-419 Shergill G, Bonney G, Munshi P et al (2001) The radial and posterior interosseous nerves. J Bone Joint Surg Br 83 646-649... 

The elbow is traversed by the ulnar, median and radial nerves that cross through its posteromedial, anterior and lateral aspects respectively. In the elbow area, the median nerve is accompanied by the brachial artery, the radial nerve gives off a main motor branch, the posterior interosseous nerve, and the ulnar nerve travels across an osteofibrous tunnel, the cubital tunnel. 

Radial Nerve and Posterior Interosseous Nerve Bursae... 

The lateral aspect of the elbow is best examined with both elbows in extension, thumbs up, palms of the hands together (Barr and Babcock 1991). When examining the radial collateral ligament and the capsule, the elbow should be extended, keeping the hand pronated. Along the lateral elbow, high-resolution US can demonstrate the common extensor tendon, the lateral ulnar collateral ligament, the radial nerve with its superficial and deep (posterior interosseous nerve) branches, and the radio-capitellar joint. 

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. 

High-resolution US is able to identify the impingement of the posterior interosseous nerve in the supinator area. The compressed nerve typically appears swollen and hypoechoic proximal to or inside the supinator muscle (Bodner et al. 2002). In post-traumatic settings, the nerve may appear displaced by a malaligned radial head and may exhibit alternate... 

Decompressive surgery of the posterior interosseous nerve is indicated if there is continuous worsening or no recovery of function with a few months. 

Fig. 8.46a,b. Posterior interosseous nerve syndrome, a Transverse 12-5 MHz US image obtained over the supinator area in patient with a previous radial head fracture and radial nerve deficit demonstrates the posterior interosseous nerve (arrowheads) entrapped within a hypoechoic scar (arrows) in the area of the supinator muscle (s). b Gross operative view shows the main trunk of the radial nerve (asterisks) as it splits into the superficial cutaneous sensory branch (arrowheads) and the deep posterior interosseous nerve (narrow arrows). This latter nerve is irregularly swollen as it passes over the bone (large arrows) as a result of the scar encasement visible in a... 

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... 

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