Anterior Interosseous Syndrome



Anterior Interosseous Syndrome


Jarrod Yamanaka, MD



BASICS



  • The anterior interosseous nerve (AIN) is a motor branch of the median nerve that innervates the pronator quadratus, flexor pollicis longus, and flexor digitorum profundus serving the index finger.


  • Anterior interosseous syndrome (AIS) is a “catch-all” term for neuropathies that result in paralysis of these muscles secondary to several causes.


  • Overall AIS is a rare condition with a paucity of research (1).


ETIOLOGY AND PATHOPHYSIOLOGY

The most frequent causes of AIS are direct traumatic nerve damage and external compression. Insidious onset of the condition thought to be a transient neuritis (1):



  • Traumatic causes:



    • Penetrating trauma


    • Blunt injury


    • Traction injury


    • Chronic vibration (cyclists)


    • Fracture


    • Surgery


    • Venipuncture


    • Injection


    • Cast pressure


  • External compression:



    • Bulky, tendinous origin of the deep head of the pronator teres


    • Soft tissue mass such as lipoma, ganglion, or tumor


    • Accessory muscle


    • Fibrous band originating from the superficial flexor


    • Vascular abnormality


Mar 14, 2020 | Posted by in SPORT MEDICINE | Comments Off on Anterior Interosseous Syndrome

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