A Martin-Gruber anastomosis (MGA) is a connection from the median nerve to the ulnar nerve in the forearm. An anastomosis occurs when two structures that normally are not connected have a connection. In this case the connection is a nerve. The Martin-Gruber anastomosis is most common anastomosis that occurs between these two nerves. This connection carries motor axons which innervate some of the usually ulnar nerve innervated intrinsic muscles.
This inconstant pattern of connection can serve as explanation for a difficult or challenging differential diagnosis. In one study, the MGA was found in 22.9% of cadaver specimens, while another found the incidence at ~11%. This relatively high incidence demonstrates the necessity for healthcare specialists to factor the MGA into their diagnoses.
Types
There are six types of Martin-Gruber anastomoses.
Clinical Significance
In the setting of proximal ulnar nerve injury, a Martin-Gruber anastomosis can prevent the complete paralysis of the intrinsic muscles of the hand.
References
- Erdem HR, Ergun S, Erturk C, Ozel S (June 2002). "Electrophysiological Evaluation of the Incidence of Martin-Gruber Anastomosis in Healthy Subjects". Yonsei Medical Journal. 43 (3): 291–5. doi:10.3349/ymj.2002.43.3.291. PMID 12089734.
- Unver Dogan, Nadire (March 14, 2009). "The communications between the ulnar and median nerves in upper limb" (PDF). neuroanatomy.org. Retrieved 2012-09-01.
- Rodriguez-Niedenführ M, Vazquez T, Parkin I, Logan B, Sañudo JR (March 2002). "Martin-Gruber anastomosis revisited". Clinical Anatomy. 15 (2): 129–34. doi:10.1002/ca.1107. PMID 11877791.
- Kaur, et al. (Feb 2016). "Martin–Gruber Anastomosis- A Cadaveric Study in North Indian Population". Journal of Clinical and Diagnostic Research. 10 (2): AC09 – AC11. doi:10.7860/JCDR/2016/16447.7247. PMC 4800503. PMID 27042438.
- Standring, Susan (2008). Gray's Anatomy 40th ed. Elsevier. p. 854. ISBN 978-0443066849.