Print this page Email this page
Users Online: 459
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Contacts Login 


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2015  |  Volume : 29  |  Issue : 3  |  Page : 169-171

Level of division of sciatic nerve in fetuses


Department of Anatomy, Regional Institute of Medical Sciences, Imphal, Manipur, India

Date of Web Publication1-Dec-2015

Correspondence Address:
P S Leishiwon
Department of Anatomy, Regional Institute of Medical Sciences, Imphal, Manipur
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0972-4958.170800

Rights and Permissions
  Abstract 

Objective: The sciatic nerve is the largest branch of the sacral plexus (L 4 -S 3 ) that is formed within the pelvis before its entry into the greater sciatic foramen. It leaves the pelvic cavity by passing through the greater sciatic foramen below the piriformis and descends along the back of the thigh, and usually divides into the common peroneal nerve and the tibial nerve just proximal to the knee. The present study aimed to study the level of division of the sciatic nerve. Materials and Methods: This study was carried out in 25 fetuses of 27-40 weeks of gestation obtained from the Department of Obstetrics and Gynecology, Regional Institute of Medical Sciences (RIMS), Imphal. The lower limbs of 25 fetuses were dissected and the sciatic nerve traced up to the level of the popliteal fossa. Results: In the present study, the lowest incidence of sciatic nerve division was found in the gluteal region (2%). In 12% of the fetuses the sciatic nerve was found to divide in the pelvic cavity before it entered into the gluteal region. The highest incidence of sciatic nerve division was found in the popliteal fossa (86%). Conclusion: Various possible variations of the sciatic nerve should be kept in mind during a surgical procedure or at the time of giving anesthesia to avoid any unwanted events. The high level of division of the sciatic nerve into the common peroneal nerve and the tibial nerve results in the involvement of only one out of the two divisions from sciatic neuropathy.

Keywords: Gluteal region, Piriformis, Popliteal fossa, Sciatic nerve


How to cite this article:
Leishiwon P S, Matum M, Devi AJ, Deven I, Devi HR, Debbarma P. Level of division of sciatic nerve in fetuses. J Med Soc 2015;29:169-71

How to cite this URL:
Leishiwon P S, Matum M, Devi AJ, Deven I, Devi HR, Debbarma P. Level of division of sciatic nerve in fetuses. J Med Soc [serial online] 2015 [cited 2022 Jan 25];29:169-71. Available from: https://www.jmedsoc.org/text.asp?2015/29/3/169/170800


  Introduction Top


The sciatic (L: 4, 5; S: 1, 2, 3) or ischiadic nerve, the largest in the body, is actually two nerves, the common peroneal and the tibial, which are usually bound together by a common sheath of connective tissue from their origin to the upper end of the popliteal space. In spite of their common connective tissue sheath, these two nerves do not interchange fibers. [1],[2] It is typically 2 cm wide at its origin, leaves the pelvis and enters the lower limb via the greater sciatic foramen below the piriformis, and descends between the greater trochanter and the ischial tuberosity along the back of the thigh, dividing into the tibial and common fibular nerves at a varying level proximal to the knee. The common site of division is usually the junction of the middle and the lower thirds of the thigh near the apex of the popliteal fossa, but the division may occur at any level above this point, and rarely may occur below it. It supplies the knee flexors and all the muscle below the knee. Therefore complete palsy of the sciatic nerve results in a flail foot and severe difficulty in walking. It also gives out articular branches to the hip joints and the knee joints. [3] The presence of variations in the relationship between the sciatic nerve and the piriformis may contribute to the occurrence of pirifomis syndrome. [4] The anatomical variations in division may also cause nerve compression resulting in sciatica, and coccygodynia. [5] The nerve is also sometimes injured by penetrating wounds, fractures of the pelvis, or dislocation of the hip joints also most frequently injured by badly placed intramuscular injections in the gluteal region. [6] The present study aimed to observe the level of division of the sciatic nerve in fetuses.


  Materials and Methods Top


This study was carried out in 25 fetuses of 27-40 weeks of gestation obtained from the Department of Obstetrics and Gynecology, Regional Institute of Medical Sciences (RIMS), Imphal. The lower limbs of the 25 fetuses were dissected bilaterally and the sciatic nerve was traced up to the level of the popliteal fossa.


  Results Top


In the present study, the lowest incidence of sciatic nerve division was found in the gluteal region (2%). In 12% of the fetuses the sciatic nerve was found to divide in the pelvic cavity before it entered into the gluteal region.



The highest incidence (86%) of sciatic nerve division was found in the popliteal fossa (Gr. F) [Figure 1]. In 12% of the cases the sciatic nerve was found to divide in the pelvis (Gr. A) proximal to the sciatic foramen before it emerged in the gluteal region [Figure 2], [Figure 4] and [Figure 5]. The tibial part passes below the piriformis, whereas the common peroneal part pierces the piriformis before emerging in the gluteal region. The lowest incidence of division was observed in the gluteal region (Gr. B), in 2% of the cases [Figure 3]. In this group, the sciatic nerve was observed passing through the greater sciatic foramen under the piriformis and then dividing into the tibial and common peroneal nerves. No cases were observed with division in the upper and middle thirds of the back of the thigh.
Figure 1: Division of sciatic nerve in the popliteal fossa

Click here to view
Figure 2: Bilateral high division of sciatic nerve in the pelvis

Click here to view
Figure 3: Sciatic nerve division in the left gluteal region

Click here to view
Figure 4: High division of sciatic nerve in the left pelvis

Click here to view
Figure 5: High division of sciatic nerve in the right pelvis

Click here to view



  Discussion Top


The commonest site of division of the sciatic nerve is at the junction of the middle and lower thirds of the back of the thigh near the apex of the popliteal fossa, but the division may occur at any level above this point and rarely below this point. [3] The sciatic nerve was found to be closer to the ischial tuberosity than the greater trochanter. During the course of the sciatic, its proximity to the ischial tuberosity causes nerve entrapment if the ischial tuberosity fractures. [7] The present study observed the bifurcation of the sciatic nerve in the gluteal region (Gr. B) in 2% of the cases, which was comparable with the studies of Ogeng'o et al. (2.4%) in the black Kenyan population [8] and Prakash et al. (2.3%) in the Indian population, [9] but was less than in the studies of Muthukumar et al. [10] (8%) in the Indian population. [10] In the present study, bifurcation of the sciatic nerve in the pelvis (Gr. A) was found in 12%, which was lower than the findings of Ogeng'o et al. (20%) [8] and Prakash et al. (16.3%). [9] Bifurcation of the sciatic nerve in the popliteal fossa (Group F) was observed in 86% in the present study, which was slightly lower than the observation made by Sulak et al. (88.5%) [7] but higher than the observation made by Ogeng'o et al. (67.1%) [8] The division of the sciatic nerve in the popliteal fossa was observed by Prakash et al. [9] in 34.9% of the cases, while it was observed in 32% by Muthukumar et al. [10]



There were no cases of division in the upper and middle thirds of the back of the thigh (between the gluteal region and the popliteal fossa).


  Conclusion Top


Various possible variations in the division of the sciatic nerve should be kept in mind during a surgical procedure or at the time of giving anesthesia or intramuscular injection in the gluteal region to avoid any unwanted events. The high level of division of the sciatic nerve into the common peroneal nerve and the tibial nerve may result in neuropathy. The high division of sciatic nerve may lead to:

  • Failure of nerve block in the popliteal fossa.
  • Nondiscogenic sciatica such as piriformis syndrome.
  • Inadvertent injury to the nerve during surgery in the gluteal region.


Knowledge regarding the different level of division of sciatic nerve is of great importance in treating fracture neck of femur, hip dislocation, and nerve block Surgeons, anesthetists, and radiologists should be aware of the possible variations in the level of division of the sciatic nerve.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

1.
Romanes GJ. Cunningham's Manual of Practical Anatomy. Vol 1. 15 th ed. Oxford: Oxford University Press; 1986. p. 123-242.  Back to cited text no. 1
    
2.
Hollinshead WH. Anatomy for surgeons. In: Hollinshead WH, editor. The Back and Limbs. Vol 3. 2 nd ed. New York: Harper and Row; 1969.  Back to cited text no. 2
    
3.
Mahadevan V. Pelvic girdle and lower limb. In: Standring S, Borley NR, Crossman AR, Gatzoulis MA, Healy JC, John D, et al. editors. Gray's Anatomy 40 th ed. Philadelphia: Churchill Livingstone; 2008. p. 1329-465.  Back to cited text no. 3
    
4.
Güvençer M, Iyem C, Akyer P, Tetik S, Naderi S. Variation in the high division of the sciatic nerve and relationship between the sciatic nerve and the piriformis. Turk Neurosurg 2009;19:139-44.  Back to cited text no. 4
    
5.
Shewale AD, Karambelkar RR, Umarji BM. Study of variation in the divisions, course and termination of the sciatic nerve. J Krishna Instt Med Sci Univ 2013;2:62-8.  Back to cited text no. 5
    
6.
Snell RS. Clinical Anatomy by Regions. 8 th ed. New Delhi: Lippincott, William & Wilkins; 2008.  Back to cited text no. 6
    
7.
Sulak O, Sakalli B, Ozguner G, Kastamoni Y. Anatomical relation between sciatic nerve and piriformis muscle and its bifurcation level during fetal period in human. Surg Radiol Anat 2014;36:265-72.  Back to cited text no. 7
    
8.
Ogeng'o JA, El-Busaidy H, Mwika PM, Khanbhai MM, Munguti J. Variant anatomy of sciatic nerve in a black Kenyan population. Folio Morphol (Warsz) 2011;70:175-9.  Back to cited text no. 8
    
9.
Prakash, Bhardwaj AK, Devi MN, Sridevi NS, Rao PK, Singh G. Sciatic nerve division: A cadaver study in the Indian population and review of the literature. Singapore Med J 2010;51:721-3.  Back to cited text no. 9
    
10.
Kumar TM, Srimathi, Rani A, Latha S. Cadaveric study of sciatic nerve and its level of bifurcation. J Clin Diagn Res 2011;5:1502-4.  Back to cited text no. 10
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Materials and Me...
Results
Discussion
Conclusion
References
Article Figures

 Article Access Statistics
    Viewed2812    
    Printed50    
    Emailed0    
    PDF Downloaded136    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]