Morphometric Analysis of Extensor Hallucis Longus Muscle - A Cadaveric Study

Abstract Background: Extensor hallucis longus (EHL) is the muscle of the anterior compartment of the leg. It has origin from the medial surface of the fibula; insertion is on the base of the distal phalanx of the big toe. Action of the muscle is an extension of the phalanges of the big toe and dorsiflexion of the foot. Tendon grafting is a very common procedure done in branches such as plastic surgery, maxillofacial surgery, and lacerated wounds of tendons where extra tendons will preserve the function of muscle. EHL is one of the preferred tendons for this purpose. The purpose of this study was to observe variations in the morphology of EHL. Methodology: The study was performed on a total 85 numbers of lower limbs available in the department of anatomy. The sample contains 46 female and 34 male cadavers. Attachments of the EHL were studied. Results: Three different types of insertion of EHL were observed: Type 1 - The most common type, insertion on the extensor hood on the dorsum of the distal phalanx, Type 2 - Two distal tendons while insertion, and Type 3 - Trilaminar insertion. Conclusion: The EHL is vital for tendon grafting in reconstruction surgeries. Its close anatomical relationship with the tibialis anterior and extensor digitorum longus highlights the need for precise morphological knowledge. Accessory tendons can be utilized without significant clinical deficits. Preoperative radiological assessment is crucial to confirm donor muscle morphology.