Morphological Study of Supratrochlear Foramen of Humerus and its Clinical Implications

Background: The supratrochlear foramen (STF), alternatively termed septal aperture of humerus is a deficit of the bony septum in the distal end of humerus that separates the coronoid fossa from the olecranon fossa. The study is focused on the STF owing to its significance in the preoperative planning of supracondylar fractures of humerus. The humerus with STF has narrow medullary canal so ante grade route is advised for nailing supracondylar fractures in humerus with STF. Materials: This study was conducted on 355 dry human humeri belonging to south Indian race. Results: The supratrochlear foramen was present in 76 bones (21.4%). The incidence of STF was more on the left side (23.3%) than the right side (19.6%). The transverse and vertical diameters of STF were measured using digital Vernier caliper. The mean transverse diameter on right side was 5.67 ± 1.71 mm and 5.39 ± 1.57 mm on left side. The mean vertical diameter was 3.9 ± 1.32 mm on right side and 3.84 ± 1.20 mm on left side. Various shapes of STF were noted among which oval shape was maximum. The translucent septum was frequently found more on the right side (56.3%). Conclusions: The STF may be mistakenly interpreted as a cyst or tumors in X rays. Besides its anthropological interest, the knowledge of STF will be helpful for orthopedic surgeons and radiologists.