Supratrochlear Foramen-anatomical Variations And Its Clinical Implications

Background: The Supratrochlear foramen (STF) is an important anatomical variation resulting from perforationof olecranon-coronoid septum present between two epicondyles of humerus.Material and methods: The study was conducted in 78 (41 left side and 37 right side) human dried humeri ofunknown sex and age. The topographical anatomy of the STF was studied in detail, morphometric measurementswere taken and specimens were photographed. Radiographs of humerus were taken to observe the translucencyof septum and the diameter of intramedullary canal was measured at three levels 1) below the surgical neck 2)junction between upper 2/3rd and lower 1/3rd of shaft 3) above the olecranon fossa.Results: Out of 78 bones studied,15 bones showed the presence of STF. The STF was oval, round and triangular inshape in 7, 5 and 3 bones respectively. The mean transverse and vertical diameters of supratrochlear foramenwere 5.46 mm,5.82 mm and 3.94mm, 3.82mm on the left and right sides respectively. The mean diameter of theintramedullary canal was 4.51mm for the humeri with STF and in the normal humeri it was 5.77mm.Conclusion: The knowledge of STF is essential in diagnostic orthopaedics, in intramedullary nailing of humerusin supracondylar fracture. STF is a radiolucent area in radiographs and this may be misinterpreted as osteolyticor cystic lesion