Anat Cell Biol.  2022 Jun;55(2):255-258. 10.5115/acb.21.246.

Bilateral absence of subclavius muscles with thickened costocoracoid ligaments: a case report with the clinical-anatomical correlation

• Dheeraj K
• Sudheer HK
• Bhukiya S
• Rani N
• Singh S

• KMID: 2531213
• DOI: http://doi.org/10.5115/acb.21.246

Abstract

Anatomical variation is defined as normal flexibility in the topography and morphology of body structures. Such variations are not uncommon in muscles, particularly in the upper limb. Subclavius muscle (SM) has a proximal attachment to the first costochondral junction and the muscle fibers are then directed upwards and laterally to get attached distally to the subclavian groove of the clavicle. Having similar attachments as the subclavius, the costocoracoid ligament (CCL) is the thickening of the proximal part of clavipectoral fascia extending up to the coracoid process. Both SM and CCL help in the maintenance of smooth movements of the pectoral girdle and both may not always be present. Absent SM may be due to anomalous development from the muscle matrix that also forms the inferior belly of the omohyoid apart from the SMs. This anatomical variation may be associated with thickened CCLs and can be correlated to the smooth functioning of the pectoral girdle.

Keyword

Costocoracoid ligament; Subclavius muscle

Figure

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  Fig. 1 Photograph showing the left pectoral region and axilla. The red arrow shows thickened left costocoracoid ligament with the absence of subclavius muscle.

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  Fig. 2 Photograph showing right pectoral region and axilla. The red arrow shows thickened right costocoracoid ligament with the absence of subclavius muscle. PM, pectoralis minor.

Reference

References

1. Kachlík D, Varga I, Báča V, Musil V. 2020; Variant anatomy and its terminology. Medicina (Kaunas). 56:713. DOI: 10.3390/medicina56120713. PMID: 33353179. PMCID: PMC7766054. PMID: 4fe6c208d3da46638529ff6a53241c84.

2. Willan PL, Humpherson JR. 1999; Concepts of variation and normality in morphology: important issues at risk of neglect in modern undergraduate medical courses. Clin Anat. 12:186–90. DOI: 10.1002/(SICI)1098-2353(1999)12:3<186::AID-CA7>3.0.CO;2-6. PMID: 10340459.

3. Yun S, Park S, Kim CS. 2018; Absence of the subclavius muscle with contralateral subclavius posticus muscle: first imaging report. Clin Imaging. 49:54–7. DOI: 10.1016/j.clinimag.2017.10.008. PMID: 29127878.

4. McCleery RS, Kesterson JE, Kirtley JA, Love RB. 1951; Subclavius and anterior scalene muscle compression as a cause of intermittent obstruction of the subclavian vein. Ann Surg. 133:588–602. DOI: 10.1097/00000658-195105000-00002. PMID: 14830129. PMCID: PMC1616903.

5. Baig MA, Bordoni B. 2021. Anatomy, shoulder and upper limb, pectoral muscles. StatPearls Publishing;Treasure Island: DOI: 10.1016/j.clinimag.2017.10.008.

6. Diwan RK, Chopra J, Anitarani , Rani A, Sehgal G, Srivastava AK. 2014; A rare variation of subclavius muscle. J Anat Sci. 22:22–5.

7. Jeon A, Seo CM, Choi YJ, Lee JH, Han SH. 2018; Innervation of subclavius muscle: an anatomical study. Int J Morphol. 36:817–20. DOI: 10.4067/S0717-95022018000300817.

8. Muellner J, Kaelin-Lang A, Pfeiffer O, El-Koussy MM. 2015; Neurogenic thoracic outlet syndrome due to subclavius posticus muscle with dynamic brachial plexus compression: a case report. BMC Res Notes. 8:351. DOI: 10.1186/s13104-015-1317-3. PMID: 26268814. PMCID: PMC4535788.

9. Atasoy E. 2004; Thoracic outlet syndrome: anatomy. Hand Clin. 20:7–14. vDOI: 10.1016/S0749-0712(03)00078-7. PMID: 15005377.

10. Teli CG, Vanitha , Kadlimatti HS, Kate N. 2015; Right sided costocoracoid ligament- a case report. Int J Anat Radiol Surg. 4:39–40. PMID: 6cbf1767ce544c119b6e25437ba171db.

11. Akita K, Ibukuro K, Yamaguchi K, Heima S, Sato T. 2000; The subclavius posticus muscle: a factor in arterial, venous or brachial plexus compression? Surg Radiol Anat. 22:111–5. DOI: 10.1007/s00276-000-0111-6. PMID: 10959678.

12. Carey F, Jones BM. 2012; Hypertrophy of the subclavius muscle accompanied by atrophy of the pectoralis muscles post-mastectomy. FASEB J. 26:724. DOI: 10.1096/fasebj.26.1_supplement.724.2.

13. Ulusoy OL, Alis D, Oz A, Barlas SB, Sokmen BK, Sever S, Mutlu A, Colakoglu B. 2018; The prevalence and characteristics of the subclavius posticus muscle in the adult population on MRI. Surg Radiol Anat. 40:1141–5. DOI: 10.1007/s00276-018-2065-6. PMID: 29974181.

14. Georgiev GP, Jelev L. 2009; Bilateral fibrous replacement of subclavius muscle in relation to nerve and artery compression of the upper limb. Int J Anat Var. 2:57–9.

15. Bamforth JS, Bell MH, Hall JG, Salter RB. 1989; Congenital shortness of the costocoracoid ligament. Am J Med Genet. 33:444–6. DOI: 10.1002/ajmg.1320330404. PMID: 2596500.

16. Crerar JW. 1892; Note on the absence of the subclavius muscle. J Anat Physiol. 26(Pt 4):554. PMID: 17232002. PMCID: PMC1328190.

17. Ebenezer DA, Rathinam BA. 2013; Rare multiple variations in brachial plexus and related structures in the left upper limb of a Dravidian male cadaver. Anat Cell Biol. 46:163–6. DOI: 10.5115/acb.2013.46.2.163. PMID: 23869264. PMCID: PMC3713281.