Background
The supratrochlear foramen of the humerus is located at the septum separating the coronoid from the olecranon fossa. Beyond its anthropologic interest, that trait seems to have clinical significance as well.
Material and Method
The supratrochlear foramen was studied in 240 macerated adult humeri. The foramen was recorded in each sex and each side. We attempted to enlighten the likely relation of the foramen with the inferior edge of the medullary canal, as well as that of the dimensions of that canal of humerus and compare it to contralateral humeri without foramen.
Results
The medullary canal width at the entry point of a retrograde intramedullary nail was statistically smaller in humeri with foramen than in humeri without it. Furthermore, the medullary canal of the humeri with foramen ends more proximally than the canal of nonforamen humeri.
Conclusions
In cases of humeral fractures of the supratrochlear foramen, the surgeon must keep in mind that it is better to perform an antegrade medullary nailing than a retrograde one; as there is higher chance of a secondary fracture, due to the extreme narrowness of the canal at the distal portion of humeri with the supratrochlear foramen.

Keywords: Humerus - surgery, Humeral Fractures - surgery, Fracture Fixation, Intramedullary - methods, Bone and Bones - surgery, Bone Nails, Anatomy - methods, Models, Anatomic, Sex Factors