Type of Article : Original Research
Year: 2015 | Volume 3 | Issue 2 | Page No. 1121-1127
Date of Publication: 30-06-2015
SCIATIC NERVE AND ITS VARIATIONS: AN ANATOMICAL STUDY
Anbumani T.L *1, Thamarai Selvi .A 2, Anthony Ammal S 3.
*1 Professor & H.O.D of Anatomy, Karpaga Vinayaga institute of medical sciences, Maduranthagam.
2 Post graduate-MD anatomy, Karpaga Vinayaga institute of medical sciences, Maduranthagam.
3 Post graduate-MD anatomy, Karpaga Vinayaga institute of medical sciences, Maduranthagam.
Address: Dr. Anbumani T.L, Professor & H.O.D of Anatomy, Karpaga Vinayaga institute of medical sciences, Maduranthagam- 603 306, Tamil Nadu, India. Phone no.: +919884715073.
Background and aims: The Sciatic nerve is the widest nerve of the body, consists of two components namely tibial and common peroneal components, derived from the lumbosacral plexus from the ventral rami of L4 to S3 spinal nerves. The Sciatic nerve usually enters the gluteal region under the piriformis muscle. The purpose of this study is to identify the variations in the course and branching pattern of the sciatic nerve and its relation to the piriformis muscle which may lead to various clinical manifestations like non-discogenic sciatica.
Materials and methods: 50 gluteal regions and posterior compartment of thigh from 25 formalin fixed adult cadavers are used for this study, of which one is a female cadaver. Gluteal regions and the posterior aspect of thigh on both sides are dissected to expose the sciatic nerve. Variations in the sciatic nerve and their relationship to piriformis muscle are observed.
Results: 41 gluteal regions and posterior compartments of thigh (82%) showed normal anatomy of sciatic nerve and also piriformis muscle. 9 regions (18%) showed variations in the sciatic nerve, of which 5 regions (10%) showed variation of sciatic nerve in relation to piriformis muscle. Other details are explained further in the article.
Conclusion: A proper knowledge about the variations of sciatic nerve, its relation to piriformis muscle is must for medical professionals during posterior hip surgeries, sciatic nerve decompression, total hip replacement, sciatic nerve injury during deep intramuscular gluteal injections, failed sciatic nerve block during anaesthetic procedures etc.
KEY WORDS: Sciatic nerve, Piriformis muscle, Piriformis syndrome.
- Datta AK, Gluteal Region. In: Essentials of human anatomy, Superior and Inferior Extremities 2009; 4th ed Kolkata Current Books International: 188-89.
- Kirschner JS, Foye PM, Cole JL. Piriformis syndrome, diagnosis and treatment. Muscle Nerve 2009;40(1):10-8.
- Demiryurek D, Bayramoglu A, Erbil M,Aldur MM, Mustafa ES. Bilateral divided piriformis muscle together with the high division of the sciatic nerve. Gazi Med J 2002;13:41-4.
- Bergman RA, Afifi AK, Miyauchi R. 1988. Compendium of human anatomical variations.
- Shewale A.D., R.R. Karambalekar, B.N. Umarji. study of variations in the divisions, course and termination of the sciatic nerve. JKIMSU 2013;2(1):62-68.
- Pokorny D, Jahoda D, Veigl D, Pinskerova V, Sonsa A. Topographic variations of the relationship of the sciatic nerve and the piriformis muscle and its relevance to palsy after total hip arthroplasty. Surg Radiol Anat 2006;28:88–91.
- Beaton LE, Anson BJ. The relation of the sciatic nerve and its subdivisions to the piriformis muscle. Anat Rec 1937;70:1–5.
- Beaton LE. The sciatic nerve and piriform muscle: Their interrelationa possible cause of coccgodynia. J Bone Joint Surgery Am 1938;20:686–688.
- Pecina M. Contribution to the etiological explanation of thepiriformis syndrome. Acta Anat (Basel) 1979;105:181–187.
- Chiba S. Multiple positional relationships of nerves arising from the sacral plexus to the piriformis muscle in humans.Kaibogaku Zasshi 1992;67(6):691–724.
- Sayson SC, Ducey JP, Maybrey JB, Wesley RL, Vermilion D:Sciatic entrapment neuropathy associated with an anomalous piriformis muscle. Pain 1994;59:149–152.
- Uluutku MH, Kurtoğlu Z. Variations of nerves located in deep gluteal region. Okajimas Folia Anat Jpn 1999;76(5):273–276.
- Moore KL, Dalley AF. Clinical Oriented Anatomy, 4th edition, Baltimore Lippincott Williams&Wilkins, 1999, 558
- Ozaki S, Hamabe T, Muro T. Piriformis syndrome resulting from an anomalous relationship between the sciatic nerve and piriformis muscle. Orthopedics 1999;22(8):771–772.
- Machado FA, Babinski MA, Brasil FB, Favorito LA, Abidu-Figureiedo M, Costa MG. Anatomical variations between sciatic nerve and priform muscle during fetal period in human. Int J Morphol 2003;21(1):29–35.
- Ugrenovic S, Jovanovic I, Krstic V, Stojanovic V, Vasovic L,Antic S, Pavlovic S. The level of the sciatic nerve division and its relations to the piriform muscle. Vojnosanit Pregl. 2005; 62(1):45–49.
- Guvencer M, Iyem C, Akyer P, Tetik S, Naderi S. Variations in the High Division of the Sciatic Nerve and Relationship Between the Sciatic Nerve and the Piriformis. Turkish Neurosurgery 2009;19(2):139-144.
- Babinski MA, Machado FA, Costa WS. A rare variation in the high division of the sciatic nerve surrounding the superior gemellus muscle. Eur J of Morphol 2003;41(1):41–42.
- Mas N, Ozekşi P, Ozdemir B, Kapakin S, Sargon MF, Celik HH,Yener N. A case of bilateral high division of the sciatic nerves,together with a unilateral unusual course of the tibial nerve. Neuroanatomy 2003;2:13–15.
- Deopujari R, Kishore Satpathi D, Mangalgiri S. Clinical importance of anatomical variants of sciatic nerve in relation to the piriformis muscle. National journal of clinical anatomy 2012;1(4):160-64.
- Prakash, Bhardwaj AK, Devi MN, Sridevi NS, Rao PK Singh G. Variations in the high division of the sciatic nerve and relationship between the sciatic nerve and the piriformis.Singapore Med J 2010;51(9):721.
- Nayak S. An unusual case of trifurcation of the sciatic nerve. Neuroanatomy 2008;5:6-7.
- Sharadkumar Pralhad Sawant. A case report on the bilateral trifurcation of the sciatic nerve and its clinical significance. International Journal of analytical, pharmaceutical and biomedical sciences 2013;2(1):24-31.
Anbumani T.L, Thamarai Selvi .A, Anthony Ammal S. SCIATIC NERVE AND ITS VARIATIONS: AN ANATOMICAL STUDY. Int J Anat Res 2015;3(2):1121-1127. DOI: 10.16965/ijar.2015.175