75 - Anatomical Relations of Median and Anterior Interosseous Nerve Branching to Muscles of the Anterior Forearm and the Palmar Cutaneous Branch of the Median Nerve

Poster Board Number: 75
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Abstract Body : The median nerve is dominantly responsible for innervating the muscles of the anterior compartment of the forearm and some muscles of the hand. Due to its location in the forearm and proximity to surrounding tissues, compression of the nerve and subsequent conditions are common. In an attempt to understand locations of entrapment, several studies have explored the branching patterns of the median nerve in the forearm. A thorough understanding of its branching in this area is crucial to the treatment of a collection of conditions, yet details of branching distribution in literature are variable. The aim of this study was to gain a detailed understanding of median nerve branching in the forearm, and to identify any associations between commonly variable median nerve distribution measures. Distance measurements between landmarks in the forearm and the nerve, and counts of the nerve insertions into muscles of the forearm were taken on 54 cadaveric limbs using standard dissection techniques. Various measures were compared to each other and values reported in literature. It was determined that the number of branches inserting into the pronator teres muscle is positively correlated to the distance between the medial epicondyle of the humerus and origin of the anterior interosseous nerve (R2 = 0.61; p = 0.02), and the number of branches inserting into the palmaris longus muscle is negatively correlated to the distance between the medial epicondyle of the humerus and origin of the anterior interosseous nerve (R2 = 0.61; p = 0.03). While several measures observed in this study agree widely with values reported in literature, many present further variation in branching distribution. Taken in concert, the results of this study asserted to the continued understanding that branching patterns of the median nerve are largely variable. Considering the clinical significance of the nerve, and its tendency to be compressed, it is evident that further dedication to exploration of median nerve distribution in the forearm is greatly necessary. Future works should aim to reduce variation in literature by replicating study conditions, dissection techniques, and the types of measurements being recorded.