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Published online: 2024-04-03

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A three-headed psoas major muscle: a case report

Marta Pośnik1, Nicol Zielinska1, Łukasz Olewnik1, Mariola Głowacka2, Piotr Łabętowicz3
Pubmed: 38567938

Abstract

Background: Multiple anatomical variations, from anomalous courses to additional structures, have been reported in muscles from different compartments of the human body. We report an extremely rare case of a psoas major muscle presenting as a three-headed structure with variable morphology. Materials and methods: During a routine dissection of the posterior abdominal wall of a 82-year-old male cadaver, an anomalous PM muscle with supernumerary head was identified, photographed and subjected to further measurement. Results: Although the anatomy of the dissected posterior abdominal wall structures was typical, a three-headed psoas major muscle composed of superficial, intermediate and deep heads was identified. Conclusions: It is important to be aware of morphological variability of muscles, especially those considered to be constant, since an anomalous structure might interfere not only with their functions, but also lead to further clinical consequences.

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References

  1. Aleksandrova JN, Malinova L, Jelev L. Variations of the iliacus muscle: report of two cases and review of the literature. Int J Anat Var. 2013; 6: 149–152.
  2. Andersson E, Oddsson L, Grundström H, et al. The role of the psoas and iliacus muscles for stability and movement of the lumbar spine, pelvis and hip. Scand J Med Sci Sports. 1995; 5(1): 10–16.
  3. D'Costa S, Ramanathan LA, Madhyastha S, et al. An accessory iliacus muscle: a case report. Rom J Morphol Embryol. 2008; 49(3): 407–409.
  4. Gibbons S. Clinical anatomy and function of psoas major and deep sacral gluteus maximus. In: Vleeming A, Mooney V, Stoeckart R. ed. Movement, stability & lumbopelvic pain: Integration of research and therapy (2nd ed). Churchill Livingstone of Elsevier, Edinburgh 2007: 98.
  5. Hides J, Stanton W, Freke M, et al. MRI study of the size, symmetry and function of the trunk muscles among elite cricketers with and without low back pain. Br J Sports Med. 2008; 42(10): 809–813.
  6. Izumoto Y, Kurihara T, Suga T, et al. Bilateral differences in the trunk muscle volume of skilled golfers. PLoS One. 2019; 14(4): e0214752.
  7. Jelev L, Shivarov V, Surchev L. Bilateral variations of the psoas major and the iliacus muscles and presence of an undescribed variant muscle--accessory iliopsoas muscle. Ann Anat. 2005; 187(3): 281–286.
  8. Ji J, Li F, Chen Q. A crucial but neglected anatomical factor underneath psoas muscle and its clinical value in lateral lumbar interbody fusion-the cleft of psoas major (CPM). Orthop Surg. 2022; 14(2): 323–330.
  9. Khalid S, Iwanaga J, Loukas M, et al. Bilateral absence of the zygomatic nerve and zygomaticofacial nerve and foramina. Cureus. 2017; 9(7): e1505.
  10. Koptas K, Zielinska N, Tubbs RS, et al. A newly reported muscle: an accessory infraspinatus or a deep layer of the latissimus dorsi? Surg Radiol Anat. 2022; 44(4): 617–620.
  11. Kostov S, Kornovski Y, Watrowski R, et al. Pelvic sidewall anatomy in gynecologic oncology — new insights into a potential avascular space. Diagnostics (Basel). 2022; 12(2).
  12. Moore KL, Dalley AF, Agur AMR. Moore's clinically oriented anatomy. Lippincott Williams, Philadelphia 2014: Wilkins.
  13. Myers TW. Poise: psoas-piriformis balance. Massage Magazine. 1998; 72: 31–39.
  14. Nachemson A. Electromyographic studies on the vertebral portion of the psoas muscle; with special reference to its stabilizing function of the lumbar spine. Acta Orthop Scand. 1966; 37(2): 177–190.
  15. Nachemson A. The possible importance of the psoas muscle for stabilization of the lumbar spine. Acta Orthop Scand. 1968; 39(1): 47–57.
  16. Olewnik Ł, Podgórski M, Polguj M. An unusual insertion of an accessory band of the semitendinosus tendon: case report and review of the literature. Folia Morphol. 2020; 79(3): 645–648.
  17. Olewnik Ł, Podgórski M, Polguj M, et al. The plantaris muscle - rare relations to the neurovascular bundle in the popliteal fossa. Folia Morphol. 2018; 77(4): 785–788.
  18. Parker A, Olewnik Ł, Iwanaga J, et al. Iliacus minor and psoas quartus muscles traversing the femoral nerve. Morphologie. 2022; 106(355): 307–309.
  19. Rao TR, Kanyan PS, Rao S. Bilateral variation of iliacus muscle and splitting of femoral nerve. Neuroanatomy. 2008; 7: 72–75.
  20. Sajko S, Stuber K. Psoas Major: a case report and review of its anatomy, biomechanics, and clinical implications. J Can Chiropr Assoc. 2009; 53: 311–318.
  21. Spratt JD, Logan BM, Abrahams PH. Variant slips of psoas and iliacus muscles, with splitting of the femoral nerve. Clin Anat. 1996; 9(6): 401–404, doi: 10.1002/(SICI)1098-2353(1996)9:6<401::AID-CA8>3.0.CO;2-D.
  22. Stewart S, Stanton W, Wilson S, et al. Consistency in size and asymmetry of the psoas major muscle among elite footballers. Br J Sports Med. 2010; 44(16): 1173–1177.
  23. Tsuyoshi S, Nagahiro T. Abdominal wall muscles. In: Tubbs RS, Shoja MM, Loukas M. ed. Bergman’s comprehensive encyclopedia of human anatomic variation. Wiley-Blackwell, Chichester 2016.
  24. Tubbs RS, Oakes WJ, Salter EG. The psoas quartus muscle. Clin Anat. 2006; 19(7): 678–680.
  25. Tubbs RS, Salter EG. The iliacus minimus muscle. Clin Anat. 2006; 19(8): 720–721.
  26. Unat F, Sirinturk S, Cagimni P, et al. Macroscopic observations of muscular bundles of accessory iliopsoas muscle as the cause of femoral nerve compression. J Orthop. 2019; 16(1): 64–68.
  27. Vleeming A, Schuenke MD, Masi AT, et al. The sacroiliac joint: an overview of its anatomy, function and potential clinical implications. J Anat. 2012; 221(6): 537–567.
  28. Wong TL, Kikuta S, Iwanaga J, et al. A multiply split femoral nerve and psoas quartus muscle. Anat Cell Biol. 2019; 52(2): 208–210.
  29. Xu WB, Chen S, Fan SW, et al. Facet orientation and tropism: Associations with asymmetric lumbar paraspinal and psoas muscle parameters in patients with chronic low back pain. J Back Musculoskelet Rehabil. 2016; 29(3): 581–586.
  30. Zielinska N, Tubbs RS, Ruzik K, et al. Classifications of the extensor hallucis longus tendon variations: Updated and comprehensive narrative review. Ann Anat. 2021; 238: 151762.