McBurney's Point: Anatomical Location and Clinical Significance
McBurney's point is located at the junction of the lateral and middle thirds of a line drawn from the umbilicus to the right anterior superior iliac spine (ASIS). This specific anatomical landmark was first described by Charles McBurney in 1889 as the location of maximal tenderness in acute appendicitis 1.
Anatomical Precision and Variations
Despite its historical significance in clinical practice, research has demonstrated that the actual location of the appendix base shows considerable variation:
- Only about 35% of appendix bases are found within 5 cm of McBurney's point 2
- Approximately 15% of appendices are located more than 10 cm away from this point 2
- 75% of appendix bases are actually positioned below and medial to the line joining the umbilicus with the right ASIS 2
- 70% of appendices lie inferior to the interspinous line (the line joining the left and right anterior superior iliac spines) 3
Distribution of Appendix Location
Research has mapped the appendix location into four quadrants with the following distribution 3:
- Iliac region: 15%
- Umbilical region: 15%
- Inguinal region: 11%
- Pelvic region: 59%
Clinical Relevance
Despite the anatomical variations, McBurney's point remains clinically significant:
- It continues to be a key reference point during physical examination for suspected appendicitis 4
- It serves as an important landmark for surgical approaches, including hybrid appendectomy techniques 5
- The World Organisation of Gastroenterology has noted that less than half of all patients with appendicitis have maximal tenderness over McBurney's point, confirming the anatomical variations 2
Surgical Applications
McBurney's point is not only important for diagnosis but also for surgical approaches:
- It serves as a reference point for incision in open appendectomy
- Modern hybrid appendectomy techniques may utilize this landmark for trocar placement 5
- Understanding the potential variations from this point is crucial for surgeons to locate the appendix effectively
The discrepancy between the classical description of McBurney's point and the actual location of the appendix in many patients highlights the importance of considering anatomical variations when evaluating patients with suspected appendicitis.