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Published online: 2024-04-25

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An unusual occurrence of a four-headed psoas major: a case report

Marta Pośnik1, Nicol Zielinska1, Konrad Kurtys1, Krzysztof Koptas1, Łukasz Olewnik1
Pubmed: 38757502

Abstract

Background: While many structures within the human body demonstrate anatomical variations, this is not typically the case for the iliopsoas muscle complex. However, the present paper describes a case of an anomalous psoas major composed of four different muscular heads in a 78-year-old male cadaver. Materials and methods: During a routine dissection of the right posterior abdominal wall, an unusual psoas major was observed, measured and photographed. Results: The psoas major was found to possess four muscular heads, otherwise the anatomy of the wall was normal. Conclusions: The presence of so many heads could interfere with the functions of the psoas major muscle. Therefore this anatomical variation merits further study.

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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. Clarkson RD, Rainy H. Unusual Arrangement of the Psoas Muscle. J Anat Physiol. 1889; 23(Pt 3): 504–506.
  3. Fabrizio PA. Anatomic variation of the iliacus and psoas major muscles. Int J Anat Var. 2011; 4: 28–30.
  4. Hansen L, de Zee M, Rasmussen J, et al. Anatomy and biomechanics of the back muscles in the lumbar spine with reference to biomechanical modeling. Spine (Phila Pa 1976). 2006; 31(17): 1888–1899.
  5. Hanson P, Magnusson SP, Sorensen H, et al. Anatomical differences in the psoas muscles in young black and white men. J Anat. 1999; 194 ( Pt 2)(Pt 2): 303–307.
  6. 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.
  7. Izumoto Y, Kurihara T, Suga T, et al. Bilateral differences in the trunk muscle volume of skilled golfers. PLoS One. 2019; 14(4): e0214752.
  8. 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.
  9. Joshi SD, Joshi SS, Dandekar UK, et al. Morphology of Psoas Minor and Psoas Accessorius. J Anat Soc India. 2010; 59(1): 31–34.
  10. Khalid S, Iwanaga J, Loukas M, et al. Split femoral nerve due to psoas tertius muscle: a review with other cases of variant muscles traversing the femoral nerve. Cureus. 2017; 9(8): e1555.
  11. Koptas K, Zielinska N, Tubbs RS, et al. An unreported infraspinatus muscle variation-two-headed infraspinatus minor muscle and three-headed fusion with the teres minor muscle. Surg Radiol Anat. 2022; 44(9): 1305–1308.
  12. Modi HN, Suh SW, Yang JH, et al. Spontaneous regression of curve in immature idiopathic scoliosis - does spinal column play a role to balance? An observation with literature review. J Orthop Surg Res. 2010; 5: 80.
  13. Moore K, Dalley AF, Agur AM. R. Clinically Oriented Anatomy (7th ed.). Lippincott Williams and Wilkins, Philadelphia 2014.
  14. MORI M. Statistics on the musculature of the Japanese. Okajimas Folia Anat Jpn. 1964; 40: 195–300.
  15. 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.
  16. Nachemson A. The possible importance of the psoas muscle for stabilization of the lumbar spine. Acta Orthop Scand. 1968; 39(1): 47–57.
  17. Olewnik Ł, Zielinska N, Koptas K, et al. Accessory part of the deltoid muscle. Folia Morphol. 2024; 83(1): 226–230.
  18. Olewnik Ł, Zielinska N, Ruzik K, et al. A new look at quadriceps tendon — Is it really composed of three layers? Knee. 2023; 40: 292–304.
  19. Parker A, Olewnik Ł, Iwanaga J, et al. Iliacus minor and psoas quartus muscles traversing the femoral nerve. Morphologie. 2022; 106(355): 307–309.
  20. Protas M, Voin V, Wang JMh, et al. A Rare Case of Double-Headed Psoas Minor Muscle with Review of its Known Variants. Cureus. 2017; 9(6): e1312.
  21. Ruzik K, Westrych K, Tubbs RS, et al. Case report of the double-headed extensor hallucis longus. Folia Morphol. 2023; 82(2): 429–433.
  22. Singh D, Agarwal S. Morphological Study of Psoas Minor Muscles with Embryological Basis and Clinical Insights. J Clin Diagn Res. 2021.
  23. 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.
  24. Tsuyoshi S. Abdominal Wall uscles. In: Tubbs RS, Shoja MM, Loukas M. ed. Bergman’s Comprehensive Encyclopedia of Human Anatomic Variation. John Wiley & Sons, Inc., Hoboken 2016.
  25. Tubbs RS, Oakes WJ, Salter EG. The psoas quartus muscle. Clin Anat. 2006; 19(7): 678–680.
  26. Watanabe K, Ohashi M, Hirano T, et al. The influence of lumbar muscle volume on curve progression after skeletal maturity in patients with adolescent idiopathic scoliosis: a long-term follow-up study. Spine Deform. 2018; 6(6): 691–698.e1.
  27. 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.
  28. Xu JJ, Zhu XL, Li T, et al. Assessment of the cross-sectional areas of the psoas major in patients with adolescent idiopathic scoliosis before skeletal maturity. Acta Radiol. 2021; 62(5): 639–645.
  29. Zielinska N, Tubbs RS, Łabętowicz P, et al. Two variant muscles in the gluteal region. Folia Morphol. 2024; 83(1): 235–238.