Nerve mapping of the thenar muscles of the hand and its relevance to selective peripheral neurectomy: a cadaveric study
Former MSc Human Anatomy student Christina Loukopoulou and her supervisors Wee Leon Lam and Abduelmenem Alashkham have presented their work at the British Association of Clinical Anatomists conference in which selective peripheral neurectomy is a surgical approach for treating spastic muscles by resecting terminal motor nerve branches.
A cartography and quantification of the muscular branching pattern of the nerves in the thenar eminence was conducted in six fresh frozen cadaveric hands. Measurements were taken from the intersections between Kaplan’s cardinal line and radial border of ring and middle finger respectively. The median nerve gave off five muscular branches, among which, three to abductor pollicis brevis (APB), one to flexor pollicis brevis (FPB) and one to opponens pollicis (OP). The ulnar nerve divided into five muscular branches to supply adductor pollicis (ADP), FPB, and the first dorsal interosseous (FDI) via three, one and one terminal branches respectively. The recurrent motor branch of median nerve (RMBMN) emerged 19.75 mm distal and radial to the first intersection and its first branch arose on average 9.70 mm from its point of origin. Resection of more than 50% of nerve fascicles from the RMBMN and DBUN supplying OP, FPB, ADP and FDI is proposed to reduce tone in the spastic thenar muscles. Nevertheless, future anatomical and clinical research is recommended to better describe the local anatomy, assess the study’s external validity and improve surgery outcomes.