The absence of piriformis muscle, combined muscular fusion, and neurovascular variation in the gluteal region

The gluteal region contains important neurovascular and muscular structures with diverse clinical and surgical implications. This paper aims to describe and discuss the clinical importance of a unique variation involving not only the piriformis, gluteus medius, gluteus minimus, obturator internus, and superior gemellus muscles, but also the superior gluteal neurovascular bundle, and sciatic nerve. A routine dissection of a right hemipelvis and its gluteal region of a male cadaver fixed in 10% formalin was performed. During dissection, it was observed a rare presentation of the absence of the piriformis muscle, associated with a tendon fusion between gluteus and obturator internus, and a fusion between gluteus minimus and superior gemellus muscles, along with an unusual topography with the sciatic nerve, which passed through these group of fused muscles. This rare variation stands out with clinical manifestations that are not fully established. Knowing this anatomy is essential to avoid surgical iatrogeny.

Persistent median artery inside the carpal tunnel: description and surgical implications

The median artery is usually a transient vessel during the embryonic period. However, this artery can persist in adult life as the persistent median artery. This paper aims to describe this relevant anatomical variation for surgeons, review the literature and discuss its clinical implications. A routine dissection was performed in the upper left limb of a male adult cadaver of approximately 50-60 years of age, embalmed in formalin 10%. The persistent median artery was identified emerging as a terminal branch of the common interosseous artery with a path along the ulnar side of the median nerve. In the wrist, the persistent median artery passed through the carpal tunnel, deep in the transverse carpal ligament. The dissection in the palmar region revealed no anastomosis with the ulnar artery forming the superficial palmar arch. The common digital arteries emerged from the ulnar artery and the persistent median artery. Such variation has clinical and surgical relevance in approaching carpal tunnel syndrome and other clinical disorders in the wrist.