Anatomic and Histological Features of the Extensor Digitorum Longus Tendon Insertion in the Proximal Nail Matrix of the Second Toe

Background: Anatomic and histological landmarks of the extensor digitorum longus (EDL) tendon insertion in the proximal nail matrix may be key aspects during surgery exposure in order to avoid permanent nail deformities. Objective: The main purpose was to determine the anatomic and histological features of the EDL’s insertion to the proximal nail matrix of the second toe. Methods: A sample of fifty second toes from fresh-frozen human cadavers was included in this study. Using X25-magnification, the proximal nail matrix limits and distal EDL tendon bony insertions were anatomically and histologically detailed. Results: The second toes’ EDLs were deeply located with respect to the nail matrix and extended superficially and dorsally to the distal phalanx in all human cadavers. The second toe distal nail matrix was not attached to the dorsal part of the distal phalanx base periosteum. Conclusions: The EDL is located plantar and directly underneath to the proximal nail matrix as well as dorsally to the bone. The proximal edge of the nail matrix and bed in human cadaver second toes are placed dorsally and overlap the distal EDL insertion. These anatomic and histological features should be used as reference landmarks during digital surgery and invasive procedures.