Ultrasound Imaging of the Sciatic Nerve Division in the Popliteal Fossa: A Volunteer Study


The Background and Objectives: A sciatic nerve block at the level of the popliteal fossa is frequently administered for post-operative analgesia for surgery below the knee. While ultrasound continues to gain popularity as the technique of choice for guiding needle positioning during peripheral nerve blocks, practitioners can begin to utilize ultrasound to look for patterns of anatomical significance. Recognizing anatomical variations among different demographic populations can help practitioners improve in performing nerve blocks. We aim to determine if predictable variability exists in sciatic nerve bifurcation location and depth at the level of the popliteal fossa. Methods: After IRB approval, eligible subjects were screened for ASA I or II status and demographic data was collected. Fifty subjects were enrolled. The SonoSite MicroMaxx? with 38-mm broadband linear array, 13-6 MHz probe with color Doppler and image capturing capabilities was used for ultrasound measurements. With subject lying prone, the location of the sciatic nerve in relation to the popliteal crease and skin-to-nerve distance were assessed via ultrasound. Two independent investigators confirmed nerve location for measurements. Analyses were performed with SAS version 9.1 using Pearson Correlation Coefficients and regression analysis. Results: Gender stratification revealed that, while males were both taller and heavier, skin-nerve measurements for depth were consistently deeper in females (p-value 0.02). Independent of the right or left leg, male gender and increased height decreases the skin-nerve distance, while increased weight increases the distance. There was no correlation between patient characteristics and crease-nerve distance. In some subjects, variability of crease-nerve distance even existed between their right and left leg. Conclusion: We show that significant variability exists for actual sciatic nerve bifurcation location, or target injection site, with consistently deeper skin depth values for female patients when compared to male patients, accounting for height and weight. These findings suggest visualization techniques such as ultrasound may lead to better localization of ideal injection sites.

Share and Cite:

E. Chiang, P. Dangerfield, D. Asay, A. Cucchiaro and J. Berger, "Ultrasound Imaging of the Sciatic Nerve Division in the Popliteal Fossa: A Volunteer Study," Open Journal of Anesthesiology, Vol. 3 No. 5, 2013, pp. 288-292. doi: 10.4236/ojanes.2013.35063.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] J. D. Vloka, A. Hadzic, E. April and D. M. Thys, “The Division of the Sciatic Nerve in the Popliteal Fossa: Anatomical Implications for Popliteal Nerve Blockade,” Anesthesia & Analgesia, Vol. 92, No. 1, 2001, pp. 215-217. doi:10.1097/00000539-200101000-00041
[2] J. D. Vloka, A. Hadzic, J. B. Lesser, E. Kitain, H. Geatz, E. W. April and D. M. Thys, “A Common Epineural Sheath for the Nerves in the Popliteal Fossa and Its Possible Implications for Sciatic Nerve Block,” Anesthesia & Analgesia, Vol. 84, No. 2, 1997, pp. 387-390.
[3] A. Nader, M. C. Kendall, K. D. Candido, H. Benzon and R. J. McCarthy, “A Randomized Comparison of a Modified Intertendinous and Classic Posterior Approach to Popliteal Sciatic Nerve Block,” Anesthesia & Analgesia, Vol. 108, No. 1, 2009, pp. 359-363. doi:10.1213/ane.0b013e31818c9452
[4] U. Schwemmer, C. K. Markus, C. A. Greim, J. Brederlau, M. Kredel and N. Roewer, “Sonographic Imaging of the Sciatic Nerve Division in the Popliteal Fossa,” Ultraschall in der Medizin, Vol. 26, No. 6, 2005, pp. 496-500. doi:10.1055/s-2005-858531
[5] S. Choi and R. Brull, “Is Ultrasound Guidance Advantageous for Interventional Pain Management? A Review of Acute Pain Outcomes,” Anesthesia & Analgesia, Vol. 113, No. 3, 2011, pp. 596-604.
[6] J. Antonakakis and B. Sites, “Equivalence is Victory,” Anesthesia & Analgesia, Vol. 113, No. 3, 2011, pp. 439-440. doi:10.1213/ANE.0b013e3182285e16
[7] A. T. Gray, “Ultrasound-Guided Regional Anesthesia: Current State of the Art,” Anesthesiology, Vol. 104, No. 2, 2006, pp. 368-373. doi:10.1097/00000542-200602000-00024
[8] G. Retzl, S. Kapral, M. Greher and W. Mauritz, “Ultrasonographic Findings of the Axillary Part of the Brachial Plexus,” Anesthesia & Analgesia, Vol. 92, No. 5, 2001, pp. 1271-1275. doi:10.1097/00000539-200105000-00037
[9] C. D. Franco, N. Choksi, A. Rahman, G. Voronov and M. H. Almachnouk, “A Subgluteal Approach to the Sciatic Nerive in Adults at 10 cm From the Midline,” Regional Anesthesia and Pain Medicine, Vol. 31, No. 3, 2006, pp. 215-220.
[10] S. B. Votruba and M. D. Jensen, “Sex-Specific Differences in Leg Fat Uptake are Revealed with a High-Fat Meal,” Endocrinology and Metabolism: American Journal of Physiology, Vol. 291, No. 5, 2006, pp. E1115-E1123. doi:10.1152/ajpendo.00196.2006
[11] C. M. Williams, “Lipid Metabolism in Women,” Proceedings of the Nutrition Society, Vol. 63, No. 1, 2004, pp. 13-160. doi:10.1079/PNS2003314
[12] E. Dufour, P. Quennesson, A. L. Van Robais, F. Ledon, P. A. Laloe, N. Liu and M. Fischler, “Combined Ultrasound an Neurostimulation Guidance for Popliteal Sciatic Nerve Block: A Prospective, Randomized Comparison with Neurostimulation Alone,” Anesthesia & Analgesia, Vol. 106, No. 5, 2008, pp. 1553-1558. doi:10.1213/ane.0b013e3181684b42
[13] A. Perlas, R. Brull, V. W. Chan, C. J. McCartney, A. Nuica and S. Abbas, “Ultrasound Guidance Improves Success of Sciatic Nerve Block at the Popliteal Fossa,” Regional Anesthesia and Pain Medicine, Vol. 33, No. 3, 2008, pp. 259-265.
[14] G. J. van Geffen, E. van den Broek, G. J. Braak, et al., “A Prospective Randomised Controlled Trial of Ultrasound Guided Versus Nerve Stimulation Guided Distal Sciatic Nerve Block at the Popliteal Fossa,” Anaesthesia and Intensive Care, Vol. 37, No. 1, 2009, pp. 32-37.
[15] T. F. Bendtsen, T. D. Nielsen, C. V. Rohde, K. Kibak and F. Linde, “Ultrasound Guidance Improves a Continuous Popliteal Sciatic Nerve Block When Compared With Nerve Stimulation,” Regional Anesthesia and Pain Medicine, Vol. 36, No. 2, 2011, pp. 181-184. doi:10.1097/AAP.0b013e31820d421f
[16] H. J. Gelfand, J. P. Ouanes, M. R. Lesley, P. S. Ko, J. D. Murphy, et al., “Analgesic Efficacy of Ultrasound-Guided Regional Anesthesia: A Meta-Analysis,” Journal of Clinical Anesthesia, Vol. 23, No. 2, 2011, pp. 90-96. doi:10.1016/j.jclinane.2010.12.005

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.