An Unusual Variety of the Extensor Digiti Muscles: Report with Notes on Repetition Strain Injuries

In over 500 human cadaveric dissections of arms and forearms, performed to the present date, we find frequent anatomical variations, corresponding to classic descriptions. Last year, we found a singular anatomic variation of the extensor muscles of the forearm, which seems previously undescribed. It is our strong belief that gross anatomy studies, and gross dissection should be updated and reintroduced in modern anatomical studies, for teaching, research, or surgical training purposes. We detected a peculiar anatomical variant of the Superficial Extensor Digiti Muscles in the forearm of a human 73 year old male Caucasian cadaver. We clearly identified a thick bundle of muscular fibres, connecting the main muscular shafts of the Extensor Digiti Minimi, and the Extensor Digitorum Communis Muscles, in a perfectly defined muscular expansion, bridging obliquely downwards and outwards, between the two main muscular shafts. In our series, this is the first occurrence of such anatomical disposition. Anatomical variations of the extensor tendons to the fingers are frequently detected in the wrist, hand and fingers compartments. The careful analysis of the variants of muscular shafts in the forearm compartment, as commonly reported in the earliest anatomical descriptions will bring renewed light to the functional assessment of the extensor mechanism of the human fingers. In this sense, we reviewed the oldest anatomical descriptions, from the 16th century to the present date.