Anatomy of Gantzer Muscle Revisited: A Descriptive Study in South Indian Cadavers

Jahira Banu,
Nithya Dhakshnamoorthy,
Sulochana Sakthivel*

Abstract

Background and Aim: Gantzer muscle (GM) is the accessory muscle associated with the flexor pollicis longus. GM could be used for muscle transfer to restore function in multiple nerve palsies. GM could be one of the causes of compressive neuropathy. This study aims to revisit the anatomy of GM and provide a detailed analysis of the morphology, dimensions, and innervation of GM in cadavers of South Indian origin. Methods and Materials: This descriptive observational study utilized 60 upper limbs from 30 cadavers that were available during the study period from June 2018 to June 2023. The shape, origin, and insertion of the GM were recorded. The length of the muscle and the tendon was measured with a digital vernier caliper. The innervation of the GM and its relation to the anterior interosseous nerve was observed. Result: The mean length of the muscle belly and tendon were 9±2.63 cm and 2.81±2.5 cm, respectively. The GM originated from the undersurface of the flexor digitorum superficialis, the coronoid process, radial tuberosity, and medial epicondyle. In 90.9% of cases, GM was innervated by the anterior interosseous nerve and 9.1% by the median nerve. Conclusion: Present study describes the morphology of GM in South Indian cadavers. Orthopaedic and hand surgeons must exercise caution when considering GM involvement in isolated anterior interosseous nerve palsy, especially when no other obvious cause is evident in the patient's clinical history. Recognizing the possibility of GM involvement is crucial in the subsequent management of compressive neuropathy.