Supracondylar process of the humerus Supracondylar process of the humerus The supracondylar process of the humerus (also known as an "avian spur") is a bony projection on the anteromedial aspect of the upper arm bone (humerus), about 5 cm above the medial epicondyle. It is directed downward, forward and medially pointing to the medial epicondyle. It is an anatomical variation which occurs in about one percent of all people. A fibrous band, Struthers ligament, may connect this process to the medial epicondyle. Supracondylar processes are usually asymptomatic, but may be palpable as a mass on the upper arm. They are most commonly found as an
Body of sphenoid bone the crest is an irregular opening leading into the corresponding sphenoidal air sinus. These sinuses are two large, irregular cavities hollowed out of the interior of the body of the bone, and separated from one another by a bony septum, which is commonly bent to one or the other side. They vary considerably in form and size, are seldom symmetrical, and are often partially subdivided by irregular bony laminae. Occasionally, they extend into the basilar part of the occipital bone nearly as far as the foramen magnum. They begin to be developed before birth, and are of a considerable size