Morphometric Study of Supratrochlear Foramen of the Humerus Related with Clinical Implications in a Thai Population

Abstract

Supratrochlear foramen (STF) is a perforation of bony wall that separates the olecranon fossa and the coronoid fossa. Its incidence varies among different races. The aim of this study was to investigate the prevalence and morphometry of supratrochlear foramen among Thai population. A total of 640 dry humeri from 320 skeletons, 160 paired humeri of each sex, and known age were collected to study the prevalence of STF. The prevalence is reported categorized by sex and the side of humerus to identify whether there is a correlation. STF is categorized by shape and their metrics measured with digital vernier calipers. The ratio of transverse diameter (TD) and distance from the medial epicondyle to the lateral epicondyle (DMLE) were calculated to represent the size of STF. From 640 humeri, 404 cases were translucent septum, 133 cases were opaque septum, and 103 cases were recorded as foramen. In this study, the majority of supratrochlear foramen were oval-shaped, followed by irregular-shaped and round-shaped foramen. The ratio between TD and DMLE was 0.09±0.44 mm on the right and 0.08±0.41 mm on the left which was not significantly different. The findings can be used to understand the variation and location of supratrochlear foramen to help radiologists and orthopedic surgeons to avoid misdiagnosis of cystic lesion at the distal humerus.