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DOI: 10.1055/s-0043-1761952
Anatomical Variants of the Upper Limb Nerves: Clinical and Preoperative Relevance
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Abstract
Profound knowledge of nerve variations is essential for clinical practice. It is crucial for interpreting the large variability of a patient's clinical presentation and the different mechanisms of nerve injury. Awareness of nerve variations facilitates surgical safety and efficacy. Clinically significant anatomical variations can be classified into two main groups: variability in the course of the nerve and variability of structures surrounding the nerve. In this review article we focus on the most common nerve variants of the upper extremity and their clinical relevance.
Publication History
Article published online:
03 April 2023
© 2023. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)
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References
- 1 Mahan M, Spinner R. Clinical importance of anatomic variation of the nerves of the upper extremity. In: Tubbs RS, Rizk E, Shoja M. et al, eds. History, Embryology, Anatomy, Imaging, and Diagnostics. Philadelphia, PA: Elsevier; 2015. 17. Tubbs RS, et al, eds. Nerve and Nerve Injuries; vol 1
- 2 Tagliafico A, Cadoni A, Fisci E. et al. Nerves of the hand beyond the carpal tunnel. Semin Musculoskelet Radiol 2012; 16 (02) 129-136
- 3 Guerri-Guttenberg RA, Ingolotti M. Classifying musculocutaneous nerve variations. Clin Anat 2009; 22 (06) 671-683
- 4 Choi D, Rodríguez-Niedenführ M, Vázquez T, Parkin I, Sañudo JR. Patterns of connections between the musculocutaneous and median nerves in the axilla and arm. Clin Anat 2002; 15 (01) 11-17
- 5 Loukas M, Aqueelah H. Musculocutaneous and median nerve connections within, proximal and distal to the coracobrachialis muscle. Folia Morphol (Warsz) 2005; 64 (02) 101-108
- 6 Caetano EB, Vieira LÂ, Cavalheiro CS, Razuk M, Almargo MA, Caetano MF. Anatomic Study of the nervous communication between the median and musculocutaneous nerve. Acta Ortop Bras 2016; 24 (04) 200-203
- 7 Olewnik Ł, Zielinska N, Karauda P, Duparc F, Georgiev GP, Polguj M. The co-occurrence of a four-headed coracobrachialis muscle, split coracoid process and tunnel for the median and musculocutaneous nerves: the potential clinical relevance of a very rare variation. Surg Radiol Anat 2021; 43 (05) 661-669
- 8 Olewnik Ł, Paulsen F, Tubbs RS. et al. Potential compression of the musculocutaneous, median and ulnar nerves by a very rare variant of the coracobrachialis longus muscle. Folia Morphol (Warsz) 2021; 80 (03) 707-713
- 9 Olewnik Ł, Wysiadecki G, Polguj M, Podgórski M, Jezierski H, Topol M. Anatomical variations of the palmaris longus muscle including its relation to the median nerve—a proposal for a new classification. BMC Musculoskelet Disord 2017; 18 (01) 539
- 10 Olewnik Ł, Podgórski M, Polguj M, Wysiadecki G, Topol M. Anatomical variations of the pronator teres muscle in a Central European population and its clinical significance. Anat Sci Int 2018; 93 (02) 299-306
- 11 Torun Bİ, Balaban M. Prevalence and clinical implications of the Gantzer's muscle. Surg Radiol Anat 2022; 44 (09) 1297-1303
- 12 al-Qattan MM. Gantzer's muscle. An anatomical study of the accessory head of the flexor pollicis longus muscle. J Hand Surg [Br] 1996; 21 (02) 269-270
- 13 Nulle K, Jaudzema A. Ultrasonographic evaluation of the median nerve: normal and variant anatomy and appearance. J Ultrason 2021; 21 (87) e318-e325
- 14 Soubeyrand M, Melhem R, Protais M, Artuso M, Crézé M. Anatomy of the median nerve and its clinical applications. Hand Surg Rehabil 2020; 39 (01) 2-18
- 15 Lanz U. Anatomical variations of the median nerve in the carpal tunnel. J Hand Surg Am 1977; 2 (01) 44-53
- 16 Kadar IA, Virág TH, Matei IR, Georgescu AV. High division of the median nerve with unusually high origin of the 3rd space common digital nerve. Injury 2020; 51 (Suppl. 04) S96-S102
- 17 Demircay E, Civelek E, Cansever T, Kabatas S, Yilmaz C. Anatomic variations of the median nerve in the carpal tunnel: a brief review of the literature. Turk Neurosurg 2011; 21 (03) 388-396
- 18 Granata G, Caliandro P, Pazzaglia C. et al. Prevalence of bifid median nerve at wrist assessed through ultrasound. Neurol Sci 2011; 32 (04) 615-618
- 19 Klauser AS, Halpern EJ, De Zordo T. et al. Carpal tunnel syndrome assessment with US: value of additional cross-sectional area measurements of the median nerve in patients versus healthy volunteers. Radiology 2009; 250 (01) 171-177
- 20 Klauser AS, Halpern EJ, Faschingbauer R. et al. Bifid median nerve in carpal tunnel syndrome: assessment with US cross-sectional area measurement. Radiology 2011; 259 (03) 808-815
- 21 Klauser AS, Faschingbauer R, Bauer T. et al. Entrapment neuropathies II: carpal tunnel syndrome. Semin Musculoskelet Radiol 2010; 14 (05) 487-500
- 22 Klauser AS, Buzzegoli T, Taljanovic MS. et al. Nerve entrapment syndromes at the wrist and elbow by sonography. Semin Musculoskelet Radiol 2018; 22 (03) 344-353
- 23 Feintisch AM, Ayyala HS, Datiashvili R. An anatomic variant of persistent median artery in association with carpal tunnel syndrome: case report and review of the literature. J Hand Surg Asian Pac Vol 2017; 22 (04) 523-525
- 24 Chiew J, Satkunanantham M, Sechachalam S. An anatomical variant of the palmar cutaneous branch of the median nerve: a case report. J Hand Surg Asian Pac Vol 2022; 27 (01) 191-194
- 25 Sur A, Sinha MM, Ughade JM. Prevalence of Martin-Gruber anastomosis in healthy subjects: an electrophysiological study from Raigarh, Chhattisgarh. Neurol India 2021; 69 (04) 950-955
- 26 Roy J, Henry BM, PĘkala PA. et al. Median and ulnar nerve anastomoses in the upper limb: a meta-analysis. Muscle Nerve 2016; 54 (01) 36-47
- 27 Rodriguez-Niedenführ M, Vazquez T, Parkin I, Logan B, Sañudo JR. Martin-Gruber anastomosis revisited. Clin Anat 2002; 15 (02) 129-134
- 28 Caetano EB, Vieira LA, Sabongi Neto JJ, Caetano MF, Sabongi RG. Riché-Cannieu anastomosis: structure, function, and clinical significance. Rev Bras Ortop 2019; 54 (05) 564-571
- 29 Marton A, Ahmed S, Jarvis GE, Brassett C, Grant I, Gaunt ME. The Berrettini palmar neural communicating branch: a study of 27 cadaveric specimens and determination of a high-risk surgical zone. J Hand Surg Eur Vol 2022; 47 (08) 851-856
- 30 Seidel GK, Seidel ME, Hakopian D. et al. Frequency of electrodiagnostically measurable Berrettini anastomosis. J Clin Neurophysiol 2020; 37 (03) 214-219
- 31 Noh JS, Park JW, Kwon HK. Palmar digital neuropathy with anatomical variation of median nerve: usefulness of orthodromic technique: a case report. Ann Rehabil Med 2019; 43 (03) 341-346
- 32 Martin SP, Schauer KT, Czyrny JJ, Ablove RH. Electrophysiological findings in common median-ulnar nerve interconnections and their clinical implications. J Hand Surg Am 2019; 44 (10) 884-894
- 33 Bhardwaj P, Venkatramani H, Sivakumar B, Graham DJ, Vigneswaran V, Sabapathy SR. Anatomic variations of the musculocutaneous nerve and clinical implications for restoration of elbow flexion. J Hand Surg Am 2022; 47 (10) 970-978
- 34 Le Minor JM. A rare variation of the median and musculocutaneous nerves in man [in French]. Arch Anat Histol Embryol 1990; 73: 33-42
- 35 Hunter DD, Skrzat J, Zdilla MJ. Bilateral absence of the musculocutaneous nerve: implications for humerus fracture and atypical median nerve palsy. Folia Med Cracov 2020; 60 (03) 27-32
- 36 Raza K, Singh S, Rani N, Mishra R, Mehta K, Kaler S. Anomalous innervation of the median nerve in the arm in the absence of the musculocutaneous nerve. Sultan Qaboos Univ Med J 2017; 17 (01) e106-e108
- 37 Guru A, Kumar N, Ravindra Shanthakumar S. et al. Anatomical study of the ulnar nerve variations at high humeral level and their possible clinical and diagnostic implications. Anat Res Int 2015; 2015: 378063
- 38 Athlani L, Delgove A, Dautel G, Casoli V. Anatomy of the ulnar nerve in the posterior compartment of the upper arm: relationships with the triceps brachii muscle. Morphologie 2020; 104 (345) 85-90
- 39 Granger A, Sardi JP, Iwanaga J. et al. Osborne's ligament: a review of its history, anatomy, and surgical importance. Cureus 2017; 9 (03) e1080
- 40 Karatas A, Apaydin N, Uz A, Tubbs R, Loukas M, Gezen F. Regional anatomic structures of the elbow that may potentially compress the ulnar nerve. J Shoulder Elbow Surg 2009; 18 (04) 627-631
- 41 Caetano EB, Sabongi Neto JJ, Vieira LA, Caetano MF. The arcade of Struthers: an anatomical study and clinical implications. Rev Bras Ortop 2017; 52 (03) 331-336
- 42 Mizia E, Zarzecki MP, Pekala JR. et al. An anatomical investigation of rare upper limb neuropathies due to the Struthers' ligament or arcade: a meta-analysis. Folia Morphol (Warsz) 2021; 80 (02) 255-266
- 43 Kowalska B, Sudoł-Szopińska I. Ultrasound assessment of selected peripheral nerves pathologies. Part II: Entrapment neuropathies of the lower limb. J Ultrason 2012; 12 (51) 463-471
- 44 Suwannakhan A, Chaiyamoon A, Yammine K. et al. The prevalence of anconeus epitrochlearis muscle and Osborne's ligament in cubital tunnel syndrome patients and healthy individuals: An anatomical study with meta-analysis. Surgeon 2021; 19 (06) e402-e411
- 45 Fadel ZT, Samargandi OA, Tang DT. Variations in the anatomical structures of the Guyon canal. Plast Surg (Oakv) 2017; 25 (02) 84-92
- 46 Murata K, Tamai M, Gupta A. Anatomic study of variations of hypothenar muscles and arborization patterns of the ulnar nerve in the hand. J Hand Surg Am 2004; 29 (03) 500-509
- 47 Niitsu M, Kokubo N, Nojima S. Variations of the ulnar nerve in Guyon's canal: in vivo demonstration using ultrasound and 3 T MRI. Acta Radiol 2010; 51 (08) 939-946
- 48 Veltre DR, Naito K, Li X, Stein AB. Aberrant positioning of the ulnar nerve found during carpal tunnel release: a case report. Orthop Rev (Pavia) 2019; 11 (03) 7795
- 49 Papanastasiou S, Sood M. Aberrant position of the ulnar nerve within the carpal canal. Microsurgery 2004; 24 (01) 24-25
- 50 Vargas CR, Chepla KJ. Report of a transligamentous ulnar nerve sensory branch. Hand (N Y) 2020; 15 (01) NP11-NP13
- 51 Bianchi S, Beaulieu JY, Poletti PA. Ultrasound of the ulnar-palmar region of the wrist: normal anatomy and anatomic variations. J Ultrasound 2020; 23 (03) 365-378
- 52 Sapage R, Pereira PA, Vital L, Madeira MD, Pinho A. Surgical anatomy of the radial nerve in the arm: a cadaver study. Eur J Orthop Surg Traumatol 2021; 31 (07) 1457-1462
- 53 Welle K, Prangenberg C, Hackenberg RK, Gathen M, Dehghani F, Kabir K. Surgical anatomy of the radial nerve at the dorsal region of the humerus: a cadaveric study. J Bone Joint Surg Am 2022; 104 (13) 1172-1178
- 54 Spinner RJ, Spinner M. Superficial radial nerve compression at the elbow due to an accessory brachioradialis muscle: a case report. J Hand Surg Am 1996; 21 (03) 369-372
- 55 Herma T, Slezak J, Baca V, Kachlik D. Duplicated superficial branch of the radial nerve and brachioradialis muscle belly: prevalence and significance. Folia Morphol (Warsz) 2022
- 56 Hemmi S, Kurokawa K, Nagai T. et al. Anatomical variations of the superficial branch of the radial nerve and the dorsal branch of the ulnar nerve: a detailed electrophysiological study. Muscle Nerve 2021; 63 (06) 913-918
- 57 Tryfonidis M, Jass GK, Charalambous CP, Jacob S. Superficial branch of the radial nerve piercing the brachioradialis tendon to become subcutaneous: an anatomical variation with clinical relevance. Hand Surg 2004; 9 (02) 191-195