Albert GRADEV, Lina MALİNOVA, Lazar JELEV

A rare muscle variation – accessory piriformis muscle

During routine anatomical dissection of the right lower limb of a 68-year-old male cadaver, a rare muscle variation wasrevealed and identified as an accessory piriformis muscle. This variant muscle started from the anterior surface of the sacrumbelow the usual piriformis muscle and extended in a well-identifiable lateral tendon also inserting to the greater trochanterof the femur. In the case described, the accessory piriformis pierced through the proximal part of the sciatic nerve. The lengthof the additional small muscle was 85 mm with the broadest part of the muscle belly as 9 mm. The course of the variantmuscle, especially its tendinous part, might irritate the sciatic nerve and cause piriformis syndrome and other sciatica-likesymptoms. The neurologists who diagnose piriformis syndrome and surgeons performing nerve releasing surgery should bewell aware of the described rare muscle variation.

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Clemente CD. Anatomy of the human body. 30th ed. Philadelphia (PA): Lea and Febiger; 1985. pp. 565–71.
Beaton LE, Anson BJ. The relation between the sciatic nerve and of its subdivisions to the piriformis muscle. Anat Rec 1938;70:1–5.
Jankovic D, Peng P, van Zundert A. Brief review. Piriformis syndrome: etiology, diagnosis, and management. Can J Anaesth 2013; 60:1003–12.
Bergman RA, Afifi AK, Miyauchi R. Illustrated encyclopaedia of human anatomic variation. Opus I: Muscular system [Revised on January 1, 2019] [Retrieved: March 2019]. Available from: https:// www.anatomyatlases.org/AnatomicVariants/MuscularSystem/Text/ P/24Piriformis.shtml
Brenner E, Tripoli M, Scavo E, Cordova A. Case report: absence of the right piriformis muscle in a woman. Surg Radiol Anat 2019 Feb 13. doi: 10.1007/s00276-018-02176–6
Natsis K, Totlis T, Konstantinidis GA, Paraskevas G, Piagkou M, Koebke J. Anatomical variations between the sciatic nerve and the piriformis muscle: a contribution to surgical anatomy in piriformis syndrome. Surg Radiol Anat 2014;36:273–80.
Adibatti M, Sangeetha V. Study on variant anatomy of sciatic nerve. J Clin Diagn Res 2014;8:AC07–9.
Sinha MB, Aggarwal A, Sahni D, Harjeet K, Gupta R, Sinha HP. Morphological variations of sciatic nerve and piriformis muscle in gluteal region during fetal period. Eur J Anat 2014;18:261–6.
Carro LP, Hernando MF, Cerezal L, Navarro IS, Fernandez AA, Castillo AO. Deep gluteal space problems: piriformis syndrome, ischiofemoral impingement and sciatic nerve release. Muscles Ligaments Tendons J 2016;6:384–96.
Lee EY, Margherita AJ, Gierada DS, Narra VR. MRI of piriformis syndrome. AJR Am J Roentgenol 2004;183:63–4.
Sen A, Rajesh S. Accessory piriformis muscle: an easily identifiable cause of piriformis syndrome on magnetic resonance imaging. Neurol India 2011;59:769–71.
Beers MH, Porter RS, Jones TV, Kaplan JL, Berkwits M. The Merck manual of diagnosis and therapy. 18th ed. New Jersey (NJ): Merck Research Laboratories; 2006. p. 2635.
Han SK, Kim YS, Kim TH, Kang SH. Surgical treatment of piri- formis syndrome. Clin Orthop Surg 2017;9:136–44.
Smoll NR. Variations of the piriformis and sciatic nerve with clinical consequence: a review. Clin Anat 2010;23:8–17.

ISSN: 1307-8798
Yayın Aralığı: Yılda 3 Sayı
Başlangıç: 2007
Yayıncı: Deomed Publishing

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