Anatomical description of a variant abductor digiti minimi accessorious muscle and its clinical correlation with ulnar neurovascular entrapment syndrome

Variations of the abductor digiti minimi muscle are a rare occurrence as compared to anomalous thenar musculature. Surgico-anatomical basis of such accessory muscular slips should be discussed in detail. This case report presents a rare bilateral existence of accessory slips of abductor digiti minimi originating from the antebrachial fascia and flexor retinaculum in a male cadaver. Hypertrophy of these muscular heads can be occult etiologies in causation of ulnar entrapment neuropathies. Such anomalous muscles can prove to be a boon or bane for an operating surgeon. On one hand, they can be the guiding factor in planning myofascial flaps and on the otherthey can cause unwanted iatrogenic complications during antero-medial approach through the wrist tendons. Nevertheless, the presence of accessory bellies in the hypothenar eminence deserve a special mention especially if present bilaterally. The authors have attempted to assign an embryological explanation for the above anomaly and have discussed its possible link with various clinical syndromes