title: Anomalous bilateral contribution of extensor pollicis longus and muscle fusion of the first compartment of the wrist.
abstract: Knowledge of the anatomical variations of the muscles of the first dorsal compartments of the wrist is clinically relevant to De Quervain's tenosynovitis and to reconstructive surgeries. In the literature, there are many reports of the presence of multiple insertion tendons in the first dorsal compartment of the wrist, but few reports describe occurrences of fusion and muscle contributions. This case report describes an anomalous bilateral contribution of the extensor pollicis longus. This anomalous contribution was found through a slender auxiliary tendon that crossed laterally under the extensor retinaculum, entered the first dorsal compartment of the wrist and merged with the tendon of the extensor pollicis brevis muscle. In the same cadaver in which this contribution was present, there was atypical muscle fusion of the abductor pollicis longus muscle and extensor pollicis brevis muscle. In conclusion, anomalous bilateral contribution of the extensor pollicis longus muscle and atypical muscle fusion, concomitant with a variant insertion pattern, are the highlight of this case report. Furthermore, it is concluded that additional tendons may be effectively used in reconstructive surgeries, but that there is a need for knowledge of the possible numerical and positional variations of these tendons, with a view to making more effective surgical plans.
authors.affiliation: Department of Structural Biology, Universidade Federal do Triângulo Mineiro, Uberaba, MG, Brazil.
authors.forename: Rodrigo César
authors.initials: RC
authors.lastname: Rosa
authors.affiliation: Department of Anatomy, Universidade Federal de Juiz de Fora, Governador Valadares, MG, Brazil.
authors.forename: Kennedy Martinez
authors.initials: KM
authors.lastname: de Oliveira
authors.affiliation: School of Medicine, Universidade de Uberaba, Uberaba, MG, Brazil.
authors.forename: Jorge Alfredo
authors.initials: JA
authors.lastname: Léo
authors.affiliation: School of Medicine, Universidade de Uberaba, Uberaba, MG, Brazil.
authors.forename: Bruno Adriano Borges
authors.initials: BA
authors.lastname: Elias
authors.affiliation: Department of Structural Biology, Universidade Federal do Triângulo Mineiro, Uberaba, MG, Brazil.
authors.forename: Paulo Ricardo
authors.initials: PR
authors.lastname: Dos Santos
authors.affiliation: Department of Biomechanics, Medicine and Rehabilitation of the Locomotor Apparatus, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Hildemberg Agostinho Rocha
authors.initials: HA
authors.lastname: de Santiago
keywords: Muscle; Tendons; Wrist