Communication of the musculocutaneous nerve with the median nerve.

Objective: To study the frequency of occurrence as well as the course and variations in the communicating branch of the musculocutaneous nerve and the relationship of the communicating branch to other structures in the upper arms of Zimbabwean subjects.

Design: Cross sectional anatomical dissections.

Setting: Department of Anatomy,University of Zimbabwe Medical School, Harare, Zimbabwe.

Subjects: Twenty four upper limbs from twelve preserved cadavers of both sexes.

Results: Eight instances of communication from musculocutaneous nerve to the median nerve were observed. Bilateral communication was observed in two cadavers. The communicating branch arose either before or after it pierced the coracobrachialis muscle. In one instance the whole musculocutaneous nerve joined the median nerve. In two instances, the musculocutaneous nerve did not pierce the coracobrachialis muscle. In two instances the communicating branch arose after the origin of the muscular branch to the biceps brachii.

Conclusions: The communicating branch was present in 33% of the cases. The communicating branch when present varied considerably in respect of its origin and its union with the median nerve. In one extreme case, the whole musculocutaneous nerve joined the median nerve and the muscular branches to the biceps brachii and brachilis arose from the median nerve. The clinician or surgeon should be aware of the presence of communicating branch and its variations in origin, course and relationships in the upper arm.