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Unusual Anatomic Split with Reunification of the Mid-Thigh Sciatic Nerve Utilizing Sonography

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Abstract

Variant sciatic nerve anatomy in the thigh occurs in about 4% of cadaveric specimens. Its significance is relevant in both clinical and surgical settings. This case describes a rare asymptomatic split with reunification of the sciatic nerve in the thigh utilizing sonography. A 27-year old male presented as a participant in a sonography research study (in preparation for publication). He was a healthy control subject without low back pain or radicular symptoms. A bilateral sonographic examination was performed to assess the sciatic nerve in the long (sagittal) and short (axial) planes. Incidentally demonstrated was a split of the sciatic nerve occurring approximately 8 cm distal to the ischial tuberosity. The finding was symmetric and bilateral. The split was maintained for 12 cm with a perpendicular epineural bridge connecting the two branches, reuniting proximal to the sciatic nerve bifurcation. Sciatic nerve variants are often described at the level of the piriformis. In contrast, there are few studies that describe variant anatomy of the sciatic nerve in the mid-thigh. Sonography provides a safe, easy, and available resource for depicting anatomic morphology of the sciatic nerve.

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References

  1. Woodley SJ, Mercer SR. Hamstring muscles: architecture and innervation. Cells Tissues Organs. 2005;179(3):125–41. https://doi.org/10.1159/000085004.

    Article  PubMed  Google Scholar 

  2. Takizawa M, Suzuki D, Ito H, Fujimiya M, Uchiyama E. The adductor part of the adductor magnus is innervated by both obturator and sciatic nerves. Clin Anat. 2014;27(5):778–82. https://doi.org/10.1002/ca.22274.

    Article  PubMed  Google Scholar 

  3. Beaton LEAB. The relation of the sciatic nerve and its subdivisions to the piriformis muscle. Anat Rec. 1937;70:1–5.

    Article  Google Scholar 

  4. Berihu BA, Debeb YG. Anatomical variation in bifurcation and trifurcations of sciatic nerve and its clinical implications: in selected university in Ethiopia. BMC Res Notes. 2015;8:633. https://doi.org/10.1186/s13104-015-1626-6.

    Article  PubMed  PubMed Central  Google Scholar 

  5. Anbumani TLTSA, Anthony Ammal S. Sciatic nerve and its variations: an anatomical study. Int J Anat Res. 2015;3(2):1121–7. https://doi.org/10.16965/ijar.2015.175.

    Article  Google Scholar 

  6. Dupont G, Unno F, Iwanaga J, Oskouian RJ, Tubbs RS. A variant of the sciatic nerve and its clinical implications. Cureus. 2018;10(6):e2874. https://doi.org/10.7759/cureus.2874.

    Article  PubMed  PubMed Central  Google Scholar 

  7. Karmakar M, Li X, Li J, Sala-Blanch X, Hadzic A, Gin T. Three-dimensional/four-dimensional volumetric ultrasound imaging of the sciatic nerve. Reg Anesth Pain Med. 2012;37(1):60–6. https://doi.org/10.1097/AAP.0b013e318232eb92.

    Article  PubMed  Google Scholar 

  8. Coppieters MW, Alshami AM, Babri AS, Souvlis T, Kippers V, Hodges PW. Strain and excursion of the sciatic, tibial, and plantar nerves during a modified straight leg raising test. J Orthop Res. 2006;24(9):1883–9. https://doi.org/10.1002/jor.20210.

    Article  PubMed  Google Scholar 

  9. Coppieters MW, Andersen LS, Johansen R, Giskegjerde PK, Hoivik M, Vestre S, et al. Excursion of the sciatic nerve during nerve mobilization exercises: an in vivo cross-sectional study using dynamic ultrasound imaging. The Journal of Orthopaedic and Sports Physical Therapy. 2015;45(10):731–7. https://doi.org/10.2519/jospt.2015.5743.

    Article  PubMed  Google Scholar 

  10. Ridehalgh C, Moore A, Hough A. Sciatic nerve excursion during a modified passive straight leg raise test in asymptomatic participants and participants with spinally referred leg pain. Man Ther. 2015;20(4):564–9. https://doi.org/10.1016/j.math.2015.01.003.

    Article  PubMed  Google Scholar 

  11. Chen J, Liu J, Zeng J, Wu S, Ren J. Ultrasonographic reference values for assessing normal sciatic nerve ultrasonography in the normal population. J Med Ultrasound. 2018;26(2):85–9. https://doi.org/10.4103/JMU.JMU_6_17.

    Article  PubMed  PubMed Central  Google Scholar 

  12. Bianchi S, Martinoli C. Ultrasound of the musculoskeletal system. In: Medical radiology. Berlin: Springer; 2007.

    Google Scholar 

  13. Taljanovic MS, Gimber LH, Becker GW, Latt LD, Klauser AS, Melville DM, et al. Shear-wave elastography: basic physics and musculoskeletal applications. Radiographics : a review publication of the Radiological Society of North America, Inc. 2017;37(3):855–70. https://doi.org/10.1148/rg.2017160116.

    Article  Google Scholar 

  14. Cingoz M, Kandemirli SG, Alis DC, Samanci C, Kandemirli GC, Adatepe NU. Evaluation of median nerve by shear wave elastography and diffusion tensor imaging in carpal tunnel syndrome. Eur J Radiol. 2018;101:59–64. https://doi.org/10.1016/j.ejrad.2018.02.005.

    Article  PubMed  Google Scholar 

  15. Arslan H, Yavuz A, Ilgen F, Aycan A, Ozgokce M, Akdeniz H, et al. The efficiency of acoustic radiation force impulse (ARFI) elastography in the diagnosis and staging of carpal tunnel syndrome. J Med Ultrason (2001). 2018;45(3):453–9. https://doi.org/10.1007/s10396-017-0857-7.

    Article  Google Scholar 

  16. Dikici AS, Ustabasioglu FE, Delil S, Nalbantoglu M, Korkmaz B, Bakan S, et al. Evaluation of the tibial nerve with shear-wave elastography: a potential sonographic method for the diagnosis of diabetic peripheral neuropathy. Radiology. 2017;282(2):494–501. https://doi.org/10.1148/radiol.2016160135.

    Article  PubMed  Google Scholar 

  17. Smoll NR. Variations of the piriformis and sciatic nerve with clinical consequence: a review. Clin Anat. 2010;23(1):8–17. https://doi.org/10.1002/ca.20893.

    Article  PubMed  Google Scholar 

  18. Varenika V, Lutz AM, Beaulieu CF, Bucknor MD. Detection and prevalence of variant sciatic nerve anatomy in relation to the piriformis muscle on MRI. Skelet Radiol. 2017;46(6):751–7. https://doi.org/10.1007/s00256-017-2597-6.

    Article  Google Scholar 

  19. Bartret AL, Beaulieu CF, Lutz AM. Is it painful to be different? Sciatic nerve anatomical variants on MRI and their relationship to piriformis syndrome. Eur Radiol. 2018;28(11):4681–6. https://doi.org/10.1007/s00330-018-5447-6.

    Article  PubMed  Google Scholar 

  20. Ridehalgh C, Moore A, Hough A. Normative sciatic nerve excursion during a modified straight leg raise test. Man Ther. 2014;19(1):59–64. https://doi.org/10.1016/j.math.2013.07.012.

    Article  PubMed  Google Scholar 

  21. Ellis R, Rohan M, Fox J, Hitt J, Langevin H, Henry S. Ultrasound elastographic measurement of sciatic nerve displacement and shear strain during active and passive knee extension. J Ultrasound Med. 2018;37(8):2091–103. https://doi.org/10.1002/jum.14560.

    Article  PubMed  Google Scholar 

  22. Tomaszewski KA, Graves MJ, Henry BM, Popieluszko P, Roy J, Pekala PA, et al. Surgical anatomy of the sciatic nerve: a meta-analysis. J Orthop Res. 2016;34(10):1820–7. https://doi.org/10.1002/jor.23186.

    Article  PubMed  Google Scholar 

  23. Nwawka OK, Meyer R, Miller TT. Ultrasound-guided subgluteal sciatic nerve perineural injection: report on safety and efficacy at a single institution. J Ultrasound Med. 2017;36(11):2319–24. https://doi.org/10.1002/jum.14271.

    Article  PubMed  Google Scholar 

  24. Battaglia PJ, Mattox R, Haun DW, Welk AB, Kettner NW. Dynamic ultrasonography of the deep external rotator musculature of the hip: a descriptive study. PM R. 2016;8(7):640–50. https://doi.org/10.1016/j.pmrj.2015.11.001.

    Article  PubMed  Google Scholar 

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Correspondence to Stacey M. Cornelson.

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All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

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Cornelson, S.M., Kettner, N.W. Unusual Anatomic Split with Reunification of the Mid-Thigh Sciatic Nerve Utilizing Sonography. SN Compr. Clin. Med. 1, 737–741 (2019). https://doi.org/10.1007/s42399-019-00121-1

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