Tendon variations of the fibularis brevis and extensor muscles in leg: a case report and a brief review of the literature.

The present case report aims to present tendon variations of the extensor hallucis longus, extensor digitorum longus, fibularis brevis and fibularis tertius. During routine dissection classes for anatomy training, accessory tendon variations were observed in both feet of a 76-year-old male Caucasian cadaver. The accessory tendons were made visible by excising the surrounding tissues. A single bilateral accessory tendon arising from the fibularis brevis, passing through the canal within the fibularis tertius tendons and ending in the dorsal aponeurosis of the fifth toe, was observed as well as a bilateral single accessory tendon originating from the extensor hallucis longus and ending on the dorsomedial side of the first metatarsophalangeal joint capsule. We came across a unilateral (right side) double accessory tendon arising from the extensor digitorum longus and ending on the body of the fifth metatarsal bone. Additionally, we detected bilateral double tendon at the insertion of the fibularis tertius on the base of the fifth metatarsal bone. These four muscles are of clinical importance because the extensor hallucis longus is used in the correction of hallux varus deformity, the fibularis brevis is used for tendon transfer in Achilles tendon ruptures, and the fibularis tertius and the extensor digitorum longus tendons are used to correct drop foot deformity. Therefore, knowing the variations of these muscles will be beneficial to clinicians.