McBurney’s Point · What Is It, Location, and More

McBurney’s point refers to the point on the lower right quadrant of the abdomen at which tenderness is maximal in cases of acute appendicitis. Acute appendicitis is characterized by the inflammation, infection, or swelling of the appendix. The sign is seen in a vast majority (approximately 91%) of individuals with appendicitis. 

The appendix is a narrow, finger-shaped pouch that projects out from the cecum, or the beginning of the large intestine. Infection likely occurs when there is a blockage in the appendix allowing the subsequent overgrowth of bacteria. As the bacteria multiply, the appendix becomes inflamed, swollen, and filled with pus. This often requires emergency surgical intervention in both children and adults—if left untreated, the appendix can rupture in as soon as 48 to 72 hours after symptoms begin. A ruptured appendix can lead to peritonitis, which is the infection and inflammation of the peritoneum, or the membrane that lines the abdominal cavity and organs. If left untreated, peritonitis can lead to widespread infection and become potentially life-threatening.

Individuals with appendicitis will typically experience a sudden onset of pain, beginning in the area behind the navel. It can then shift to the lower right abdomen, where the appendix is located. Associated symptoms include low-grade fever, nausea, vomiting, constipation, diarrhea, and abdominal bloating. 

A physical exam may reveal rebound tenderness over McBurney’s point. Rebound tenderness is a clinical sign in which there is pain upon removal of pressure rather than application of pressure to the abdomen. Other clinical signs indicative of acute appendicitis include Rovsing’s sign, Psoas sign, and a positive obturator sign. Rovsing's sign is said to be positive if pressure over the person’s left lower abdominal quadrant causes pain in the right lower abdominal quadrant. The Psoas sign is elicited in an individual lying on their left side while their right thigh is flexed backward. While in this position, the inflamed appendix may press against the right Psoas muscle, which connects the lumbar vertebrae to the femur. This can cause pain, triggering the individual to shorten the muscle by drawing up the right knee. Additionally, the appendix may also lie against the right obturator internus muscle, a deep muscle of the hip joint. The obturator sign can be elicited in an individual by flexing their right knee to a 90 degree angle while a clinician internally rotates the hip by moving the ankle away from the body. Pain associated with this maneuver can be indicative of an inflamed appendix. 

To aid in the diagnosis of acute appendicitis, laboratory studies to assess for inflammation may be used. This can include looking at the white blood cell count (WBC) and C-reactive protein (CRP). Both WBC and CRP are elevated during times of inflammation and infection, and can be strongly suggestive of acute appendicitis. Imaging techniques such as computed tomography (CT) and ultrasound are commonly used to visualize the appendix. Common imaging findings include dilated or enlarged appendix, wall thickening, or detection of abscess or inflammatory masses.