153 The Martin-Gruber Anastomosis: Prevalence and Morphology

Abstract

Abstract Introduction The Martin-Gruber anastomosis (MGA) is an anatomical variant characterised by an anastomotic branch between the median and ulnar nerves in the forearm. The MGA can cause changes to the innervation of the hand in 6% to 47.3% of the population. However, this change in innervation remains asymptomatic unless the MGA co-exists with a peripheral neuropathy, such as carpal tunnel syndrome (CTS). Aim This study aimed to investigate both the prevalence and morphology of the MGA in a cadaveric population. Method Fourteen embalmed right-upper limbs were dissected to the level of the MGA, using standard dissecting techniques, and evaluated for the presence of the characteristics of the MGA. Results The results showed the MGA was present in 14.4% (2/14) of the population. One case was found to originate directly from the median nerve. The second case originated from the anterior interosseous nerve. Conclusions This study emphasises the need for medical professionals to recognise and understand the implications of the anastomosis on common peripheral neuropathies, particularly CTS, whose co-existence can create unusual innervation of the upper limb.