Preventing Iatrogenic Injury to the Dorsomedial Cutaneous Nerve of the Hallux

Abstract

The dorsomedial cutaneous nerve of the hallux (DMCN) is a sensory nerve that crosses the extensor hallucis longus (EHL) tendon to innervate the great toe and the first metatarsophalangeal joint. The DMCN is vulnerable to injury during operative procedures including hallux valgus or hallux rigidus correction, bunionectomy, and cheilectomy, as well as EHL tendon transfer surgeries. Intraoperative injury to the DMCN may cause pain that is intractable without subsequent surgical intervention. Accordingly, understanding anatomical variation of the DMCN is of the utmost importance. Therefore, this study assessed 23 cadaveric legs and feet to identify morphological variations of the DMCN. Observed variations included supernumerary branches crossing the EHL tendon and atypical superficial fibular nerve branching that affected the anatomical relationship between the DMCN and the EHL tendon. This study provides details of atypical variations of the DMCN and the resulting data, when used in conjunction with current imaging techniques (ultrasonography), may help to prevent unwarranted iatrogenic nerve injury.