Obturator Sign
Introduction
The Obturator Sign, also known as Cope’s Obturator Test or the Thigh-Rotation Test, was first described in 1919 by Sir Vincent Zachary Cope (1881–1974), an English surgeon.[1][2]
Purpose
The Obturator Sign works on the same principle as the Psoas Sign, stretching a pelvic muscle that’s irritated by an inflamed appendix will cause pain.[3]
Technique
- Ask the patient to lie supine on the examination table.
- The examiner stands on the patient’s right side.
- Flex the patient’s right hip and knee to 90°.
- Internally rotate the hip by moving the ankle outward while keeping the knee stationary.
- Observe for pain in the lower abdomen or pelvis during this movement.
- Positive Obturator Sign: Pain indicates irritation of the obturator internus muscle, often due to appendicitis, pelvic abscess, or inflammatory fluid.[4]
The following video will show how to perform the test;
Evidence
The Obturator Sign shows low sensitivity (8%) but high specificity (94%) for diagnosing acute appendicitis meaning it is uncommon but quite reliable when present.[1]
References
- ↑ 1.0 1.1 Rastogi V, Singh D, Tekiner H, Ye F, Mazza JJ, Yale SH. Abdominal physical signs and medical eponyms: movements and compression. Clinical Medicine & Research. 2018 Dec 26;16(3-4):76-82.
- ↑ Cadogan, M. (2022) Appendicitis - the eponymous examination, Life in the Fast Lane • LITFL. Life in the Fast Lane. Available at: https://litfl.com/appendicitis-eponyms/ (Accessed: October 7, 2025).
- ↑ McGee S. Evidence-based physical diagnosis e-book. Elsevier Health Sciences; 2021 Jul 8.
- ↑ Macaluso CR, McNamara RM. Evaluation and management of acute abdominal pain in the emergency department. International journal of general medicine. 2012 Sep 26:789-97.
- ↑ Youtu.be. Available at: https://youtu.be/8aPz8UP9G58?si=D19xuEQ9j0hUIKJ7 (Accessed: October 7, 2025).