Fetal anatomy of the connections of the median and ulnar nerves on the palm of the hand
DOI:
https://doi.org/10.15574/PP.2025.3(103).128136Keywords:
palm, hand, median nerve, ulnar nerve, fetus, anatomical variability, humanAbstract
In traumatic injuries of brachial plexus branches, one of the important compensatory mechanisms of peripheral innervation is the connections between nerves.
Аim - to determine the connections between the median and ulnar nerves in the hand in human fetuses and to clarify the projection of these connections to the skin of the palm for timely diagnosis and treatment of damage to these nerves.
Materials and methods. We studied 48 hand preparations using macro-microscopic dissection and morphometry of human fetuses aged 4-10 months.
Results. In 37 cases, connections were found in the palm area between the median and ulnar nerves that were variable in shape. Our study gives us the right to consider inaccurate the indications of anatomical manuals that 3.5 fingers on the palm are innervated by the median nerve and 1.5 fingers by the ulnar nerve. The innervation of the skin of the palmar surface of 3.5 fingers by the median nerve and 1.5 fingers by the ulnar nerve can be said to be the case only if there is no connection between the median and ulnar nerves in the palm, which happens in 22.9% of cases.
Conclusions. In fetuses, a branch of the ulnar nerve to the median nerve can be found on the palm in 77.1% of cases. There are four types of connections between the median and ulnar nerves: straight (62.2%), Y-shaped (21.6%), X-shaped (10.8%), and T-shaped (5.4%). In human fetuses, due to almost constant connections in the form of connecting branches between the median and ulnar nerves, the palm of the hand has clearly defined areas of overlap of one nerve with branches of the other nerve. The palmar area of the skin from the radial edge of the index finger to the radial edge of the little finger inclusive is an "overlapping zone" because of the dual innervation within it.
The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the institution mentioned in the paper.
No conflict of interests was declared by the authors.
References
Adler JA, Wolf JM. (2020). Proximal Median Nerve Compression: Pronator Syndrome. J Hand Surg Am. 45(12): 1157-1165. https://doi.org/10.1016/j.jhsa.2020.07.006; PMid:32893044
Biryuk IG, Khmara TV, Pankiv TV, Martsenyak IV, Sykyrytska TB, Kukovska IL. (2024). Peculiarities of dissection of vessels and nerves of the palmar part of the hand. Clinical Anatomy and Operative Surgery. 23(4): 98-105. https://doi.org/10.24061/1727-0847.23.4.2024.74
Cline JA, Frantz LM, Adams JM, Hearon BF. (2024). Experience With Proximal Median Nerve Entrapment by the Lacertus Fibrosus. Hand (NY). 19(6): 904-911. https://doi.org/10.1177/15589447231153233; PMid:36859808 PMCid:PMC11342709
Coraci D, Loreti C, Piccinini G, Doneddu PE, Biscotti S, Padua L. (2018). Ulnar neuropathy at wrist: entrapment at a very "congested" site. Neurol Sci. 39(8): 1325-1331. https://doi.org/10.1007/s10072-018-3446-7; PMid:29779137
Del Piñal F. Re: Tang JB. (2022). Median nerve compression: lacertus syndrome versus superficialis-pronator syndrome. J Hand Surg Eur. 2021, 46: 1017-22. J Hand Surg Eur. 47(5): 538-539. https://doi.org/10.1177/17531934221076298; PMid:35130785
Georgiew F, Maciejczak A, Florek J, Kotela I. (2020). Ulnar and Median Nerve Abnormalities in Carpal Tunnel Syndrome. Ortop Traumatol Rehabil. 22(5): 311-318. https://doi.org/10.5604/01.3001.0014.4214; PMid:33568572
Ginanneschi F, Mondelli M, Cioncoloni D, Rossi A. (2018). Impact of carpal tunnel syndrome on ulnar nerve at wrist: Systematic review. J Electromyogr Kinesiol. 40: 32-38. https://doi.org/10.1016/j.jelekin.2018.03.004; PMid:29587171
Goubier JN, Battiston B, Casanas J, Quick T. (2024). Adult traumatic brachial plexus injuries: advances and current updates. J Hand Surg Eur Vol. 49(6): 734-746. https://doi.org/10.1177/17531934241229201; PMid:38366385
Le Hanneur M, Lafosse T, Cambon-Binder A, Belkheyar Z. (2019). Surgical strategy in extensive proximal brachial plexus palsies. Musculoskelet Surg. 103(2): 139-148. https://doi.org/10.1007/s12306-018-0552-x; PMid:29961233
Hill JR, Lanier ST, Rolf L, James AS, Brogan DM, Dy CJ. (2023). Trends in Brachial Plexus Surgery: Characterizing Contemporary Practices for Exploration of Supraclavicular Plexus. Hand (NY). 18; 1 suppl: 14S-21S. https://doi.org/10.1177/15589447211014613; PMid:34018448 PMCid:PMC9896279
Hosapatna M, Souza AD, Rao M, Hari Ankolekar V. (2020). Morphology and innervation of brachioradialis and flexor carpi radialis and their utility in tendon transfer surgeries: A Cadaveric Study. Morphologie. 104(345): 91-96. https://doi.org/10.1016/j.morpho.2019.10.046; PMid:31761660
Huang CW, Yin CY, Huang HK, Chen TM, Hsueh KK, Yang CY et al. (2021). Influential factors of surgical decompression for ulnar nerve neuropathy in Guyon's canal. J Chin Med Assoc. 84(9): 885-889. doi: 10.1097/JCMA.0000000000000583. Erratum in: J Chin Med Assoc. 2022 Feb 1; 85(2): 263. https://doi.org/10.1097/JCMA.0000000000000686; PMid:34999636
Kahn LC, Stonner MM, Dy CJ. (2024). Key Considerations for Nerve Transfer Rehabilitation After Surgical Reconstruction for Brachial Plexus and Peripheral Nerve Injuries. J Hand Surg Am. 49(2): 160-168. https://doi.org/10.1016/j.jhsa.2023.09.016; PMid:37999701
Karvelas KR, Walker FO. (2019). Clinical and Ultrasonographic Features of Distal Ulnar Neuropathy: A Review. Front Neurol. 10: 632. https://doi.org/10.3389/fneur.2019.00632; PMid:31293494 PMCid:PMC6601364
Murata K, Shih JT, Tsai TM. (2003). Causes of ulnar tunnel syndrome: a retrospective study of 31 subjects. J Hand Surg Am. 28(4): 647-51. https://doi.org/10.1016/S0363-5023(03)00147-3; PMid:12877855
Naik AA, Bawa A, Arya A, Gulihar A. (2021). Nerve entrapment around elbow. J Clin Orthop Trauma. 19:209-215. doi: 10.1016/j.jcot.2021.05.031. Erratum in: J Clin Orthop Trauma. 2021 Jul 30; 20: 101539. https://doi.org/10.1016/j.jcot.2021.101539; PMid:34405084 PMCid:PMC8350372
Patel K, Horak HA. (2021). Electrodiagnosis of Common Mononeuropathies: Median, Ulnar, and Fibular (Peroneal) Neuropathies. Neurol Clin. 39(4): 939-955. https://doi.org/10.1016/j.ncl.2021.06.004; PMid:34602220
Spinner RJ, Wang H, Howe BM, Colbert SH, Amrami KK. (2012). Deep ulnar intraneural ganglia in the palm. Acta Neurochir (Wien). 154(10): 1755-63. https://doi.org/10.1007/s00701-012-1422-1; PMid:22729483
Strohl AB, Zelouf DS. (2017). Ulnar Tunnel Syndrome, Radial Tunnel Syndrome, Anterior Interosseous Nerve Syndrome, and Pronator Syndrome. J Am Acad Orthop Surg. 25(1): e1-e10. https://doi.org/10.5435/JAAOS-D-16-00010; PMid:27902538
Tang JB. (2022). Some Misconceptions in the Treatment of Cubital Tunnel Syndrome, Radial Tunnel Syndrome, and Median Nerve Compression in the Forearm. Hand Clin. 38(3): 321-328. https://doi.org/10.1016/j.hcl.2022.02.003; PMid:35985756
Teodonno F, Maffeis J, Latini F, Chevrier B, Teboul F. (2025). Intraosseous Nontraumatic Median Nerve Entrapment at the Elbow: A Case Report. Hand (N Y). 20(1): NP1-NP6. https://doi.org/10.1177/15589447231222319; PMid:38265033 PMCid:PMC11571333
Thamm OC, Eschborn J, Schäfer RC, Schmidt J. (2024). Advances in Modern Microsurgery. J Clin Med. 13(17): 5284. https://doi.org/10.3390/jcm13175284; PMid:39274497 PMCid:PMC11396389
Thaploo D, Bhat DI, Kulkarni MV, Devi BI. (2019). Brachial plexus injury and resting-state fMRI: Need for consensus. Neurol India. 67(3): 679-683. https://doi.org/10.4103/0028-3886.263178; PMid:31347534
Wu KY, Spinner RJ, Shin AY. (2022). Traumatic brachial plexus injury: diagnosis and treatment. Curr Opin Neurol. 35(6): 708-717. https://doi.org/10.1097/WCO.0000000000001124; PMid:36302200
Zamborsky R, Kokavec M, Simko L, Bohac M. (2017). Carpal Tunnel Syndrome: Symptoms, Causes and Treatment Options. Literature Reviev. Ortop Traumatol Rehabil. 19(1):1-8. https://doi.org/10.5604/15093492.1232629; PMid:28436376
Downloads
Published
Issue
Section
License
Copyright (c) 2025 Ukrainian Journal of Perinatology and Pediatrics
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
The policy of the Journal “Ukrainian Journal of Perinatology and Pediatrics” is compatible with the vast majority of funders' of open access and self-archiving policies. The journal provides immediate open access route being convinced that everyone – not only scientists - can benefit from research results, and publishes articles exclusively under open access distribution, with a Creative Commons Attribution-Noncommercial 4.0 international license(СС BY-NC).
Authors transfer the copyright to the Journal “MODERN PEDIATRICS. UKRAINE” when the manuscript is accepted for publication. Authors declare that this manuscript has not been published nor is under simultaneous consideration for publication elsewhere. After publication, the articles become freely available on-line to the public.
Readers have the right to use, distribute, and reproduce articles in any medium, provided the articles and the journal are properly cited.
The use of published materials for commercial purposes is strongly prohibited.
