McBurney's point

Editor-in-Chief: Imtiaz Ahmed Wani, MBBS, MS, Registrar Surgery, S.M.H.S Hospital, Srinagar, Kashmir, India [mailto:imtazwani@yahoo.com]

Overview
McBurney's point is the name given to the point over the right side of the human abdomen that is one-third of the distance from the ASIS (anterior superior iliac spine) to the umbilicus. This point roughly corresponds to the most common location of the base of the appendix where it is attached to the cecum.

The anterior cutaneous branch of iliohypogastric nerve is found near McBurney's point.

Eponym
The sign is named for Charles McBurney, U.S. surgeon, 1845–1913.

Clinical relevance
Deep tenderness at McBurney's point, known as McBurney's sign, is a sign of acute appendicitis. The clinical sign of rebound pain when pressure is applied is also known as Aaron's sign.

Specific localization of tenderness to McBurney's point indicates that inflammation is no longer limited to the lumen of the bowel (which localizes pain poorly), and is irritating the lining of the peritoneum at the place where the peritoneum comes into contact with the appendix. Tenderness at McBurney's point suggests the evolution of acute appendicitis to a later stage, and thus, the increased likelihood of rupture. Because the location of the appendix is often different in different people, and can migrate within the abdomen, many cases of appendicitis do not cause point tenderness at McBurney's point. Other abdominal processes can also sometimes cause tenderness at McBurney's point. Thus, this sign is highly useful but neither necessary nor sufficient to make a diagnosis of acute appendicitis. Also, the anatomical position of the appendix is highly variable (for example in retrocaecal appendix, an appendix behind the caecum), which also limits the use of this sign.