Bony projection from the olecranon process of ulna

Abstract

During examination of ulna in the osteology lab in the department of anatomy, CSMMU, Lucknow, UP, India,author found four ulnae showing new bony projections from the posterior part of olecranon processes. Incidence of this bony projection is 4%. The average length, breadth and thickness were 9 mm, 1.2 mm and 4 mm respectively. These bony projections may impinge on the triceps muscle and surrounding structures causing spasm of muscle and compression of structures leading to pain during biomechanical movements of the shoulder joint, elbow and hand. The bony projection may cause misinterpretation of radiographs. Thus knowledge of this bony projection is of paramount importance to clinicians, radiologists and anatomists. Key words: Ulna, olecranon process, bony projection, triceps brachi