ANATOMY OF THE NUTRIENT FORAMEN ON THE HUMERUS, RADIUS AND ULNA: A REVIEW

Objective: the nutrient foramina are reported as a cause for union defects in humerus, radius and ulna fractures. we aimed to review the relationship between the anatomy of the nutrient foramina and fractures of these bones.materials and methods: we performed an internet search via pubmed and google scholar. we obtained full-text articles of 27 papers. we included 23 articles in our study. eight studies investigated only humerus, 1 investigated radius, 1 investigated ulna, 1 investigated radius and ulna, and 12 investigated all three bones. we used additional 21 articles for a clinical viewpoint. therefore 44 references were included in our study.results: for humerus, foraminal index (the ratio of the distance between nutrient foramen and proximal end of the bone to total bone length) ranged between 32.7 and 59.1, and mostly the foramina located at the anteromedial surface. for radius, foraminal index ranged between 32.7 and 44.52, and mostly the foramina located at the anterior surface. for ulna, foraminal index ranged between 35.7 and 41.97, and mostly the foramina located at the anterior surface.conclusion: the number and location of the foramina are concordant among different ethical groups. the most common site of union defects for humerus is the proximal 1/3. this complication is attributed to the attachments of strong skeletal muscles to this region. in forearm, non-unions tend to occur at the distal 1/3. at this region, blood supply is diminished due to the decrease of number of branches from the nutrient artery