Feb 16, 2026

Public workspaceA complete insight on obturator nerve anatomy and its clinical implications

DOI
https://dx.doi.org/10.17504/protocols.io.14egn1jmyv5d/v1
  • Ashwin R Rai1,
  • Latha V Prabhu1,
  • Rajangandha Vadgaonkar1,
  • Mangala M. Pai1
  • 1Department of Anatomy, Kasturba Medical College, Mangalore-575001, A Constituent Unit of Manipal Academy of Higher Education, Manipal, Karnataka, India
  • Anatomy
ashwin.rai
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DOI: https://dx.doi.org/10.17504/protocols.io.14egn1jmyv5d/v1
Protocol Citation: Ashwin R Rai, Latha V Prabhu, Rajangandha Vadgaonkar, Mangala M. Pai 2026. A complete insight on obturator nerve anatomy and its clinical implications. protocols.io https://dx.doi.org/10.17504/protocols.io.14egn1jmyv5d/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License,  which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: February 16, 2026
Last Modified: February 16, 2026
Protocol Integer ID: 243351
Keywords: obturator nerve anatomy, complete insight on obturator nerve anatomy, pubic tubercle, patient during on block, medial compartment, anaesthetist, causing pain
Abstract
The study will report more information about the distribution pattern of ON in the medial compartment which is of academic interest. The study of various parameter in approaching the ON with the help of pubic tubercle is of utmost importance in guiding the anaesthetist without causing pain and discomfort to the patient during ON block. 
Guidelines
The anatomy of ON will be studied:

1. In the pelvis
2. At the Obturator nerve exit
3. In the thigh
4. Its branching pattern
5. Areas of distribution

When considering the various approach for ON block the following measurements (cm) will be noted on same side.

1. The depth of the needle when inserted 0.5cm below the pubic tubercle to the Obturator nerve exit in the thigh
2. Distance from midpoint of femoral artery traced just 0.5cm below the inguinal ligament to the depth of the needle
3. Distance of Anterior superior iliac spine to pubic tubercle
4. Distance from Anterior superior iliac spine to the medial condyle of the femur.
Materials
The present study will include 50 lower limb (right 26 left) dissected from cadavers of known sex available in the Anatomy department of our institution. The specimen of lower limb without the pelvis will not be considered for this study. The materials which will be used for the study will be needle, measuring tape and marker.
Troubleshooting
Materials and Methods
The present study will include 50 lower limb (right 26 left) dissected from cadavers of known sex available in the Anatomy department of our institution. The specimen of lower limb without the pelvis will not be considered for this study. The materials which will be used for the study will be needle, measuring tape and marker.
The anatomy of ON will be studied:
In the pelvis
At the Obturator nerve exit
In the thigh
Its branching pattern
Areas of distribution
When considering the various approach for ON block the following measurements (cm) will be noted on same side.
The depth of the needle when inserted 0.5cm below the pubic tubercle to the Obturator nerve exit in the thigh
Distance from midpoint of femoral artery traced just 0.5cm below the inguinal ligament to the depth of the needle
Distance of Anterior superior iliac spine to pubic tubercle
Distance from Anterior superior iliac spine to the medial condyle of the femur.
Protocol references
1. John Sison Tipton. Obturator neuropathy. Curr Rev Musculoskelet Med. 2008;1(3-4): 234–237.
2. Hadley G. Essential clinical anatomy. J Anat. 2007;211:413.
3. Bradshaw C, McCrory P, Bell S, Brukner P. Obturator nerve entrapment. A cause of groin pain in athletes. Am J Sports Med. 1997;25(3):402-408.
4. Kumka M. Critical sites of entrapment of the posterior division of the obturator nerve: anatomical considerations. J Can Chiropr Assoc. 2010;54(1):33-42.
5. Macaire P, Joubert C, Jochum D, Gaertner E, Choquet O. Should an obturator nerve block be combined to femoral and sciatic nerve blocks for knee surgery purposes? Anesthesiology 2003; 99:A1041.
6. Hızlı F, Argun G, Güney I, Güven O, Arık AI, Başay S, Günaydın H, Başar H, Köşüş A. Obturator nerve block transurethral surgery for bladder cancer: comparison of inguinal and intravesical approaches: prospective randomized trial. Ir J Med Sci. 2016;185(3):555-560.
7. Tatlısen A, Sofikerim M. Obturator nerve block and transurethral surgery for bladder cancer. Minerva Urol Nefrol. 2007;59(2):137-141.