Guttering Interosseous Atrophy

In the hand there are four dorsal interossei which lie superficially inbetween the metacarpals on the dorsum of the hand.

Guttering interosseous atrophy.

Dorsal guttering due to wasted interossei muscles palpate the 1st finger web where the wasting is often obvious. Causes include compression of the ulnar nerve by an aponeurotic band that runs from the medial epicondyle of the humerus to the medial border of the olecranon direct trauma to the. Wasting of the interossei prominent guttering of the back of the hand of the web space between thumb and index finger and softening and flattening of the hypothenar eminence with sparing of abductor pollicis brevis indicates an ulnar nerve lesion. There are four dorsal interossei in each hand.

When assessed by needle emg the first dorsal interosseous is the muscle most likely to be affected followed by the abductor digit quinti and flexor carpi ulnaris. They are specified as dorsal to contrast them with the palmar interossei which are located on the anterior side of the metacarpals. Electrodiagnostic studies are able to differentiate une from radiculopathies and lower trunk plexopathy. The dorsal interosseous muscles are bipennate with each muscle arising by two heads from the adjacent sides of the metacarpal bones but more extensively from the metacarpal bone of the finger into.

The position of the insertion site is dependent on which digit is involved. Each muscle is bipennate in shape and extends from the proximal ends of adjacent metacarpals to the proximal phalanx and dorsal digital expansion of the appropriate finger. Interossei weakness atrophy and claw hands may be noted in severe cases. Waldman md jd in atlas of common pain syndromes fourth edition 2019.