Traumatic Hallux Varus in Association with Agenesis of the Fibular Sesamoid: A Case Study.

Hallux varus is most commonly seen iatrogenically following overaggressive lateral release, removal of the fibular sesamoid, or overaggressive removal of the medial eminence. There are several reported cases of traumatic hallux varus, although this is much less common. We present a case of traumatic hallux varus in a patient who was later found to have bilateral absence of her fibular sesamoids. We postulated that lack of her fibular sesamoid led to weakness of her lateral capsular ligaments, thereby making her more susceptible to this injury. We performed a repair using a split extensor hallucis longus tendon transfer that was transected proximally, rerouted the tendon under the deep transverse intermetatarsal ligament, and secured it to the first metatarsal with a Bio-Tenodesis (Arthrex, Inc, Naples, Florida) screw. At 22 months postoperatively, she has demonstrated maintenance of correction and has resumed use of normal shoe gear and participation in activities. Our goal was to demonstrate a repair for this condition that successfully maintained correction over time while still allowing for functionality of the first metatarsophalangeal joint.