Variantes Anatómicas dos Músculos Extensores dos Dedos da Mão

Abstract

The extensor tendons of fingers are subject of many variations, some of them quite frequent. The dissection of the posterior region of forearm and hand was carried out, and the anatomical variations were documented. In Case 1 the extensor digitorum divided into 5 tendons: one for the index finger, one for the middle finger, two for the ring finger and one for the little finger; the extensor indicis proprius divided into two tendons: one for the index and one for the middle finger. In Case 2 the extensor digitorum divided into 4 tendons: one tendon joined the extensor pollicis longus, one tendon for the index, one for the middle finger and one for the ring finger with one slip to the little finger; the extensor indicis proprius divided into two tendons, one for the index and one for the middle finger; the extensor digiti minimi divided into two slips for the little finger. The existence of a double tendon from extensor digitorum for the ring finger is described in several studies. The tendinous slip from extensor digitorum to extensor pollicis longus is not a frequent finding. The double tendon from extensor digiti minimi may occur in 60 to 90% of cases. The knowledge of the most common variations of the tendons of extensor muscles is very important in surgical practice.