[The anatomical variations of the extensor muscles of the hand fingers].

INTRODUCTION: The extensor tendons of fingers are subject of many variations, some of them quite frequent. MATERIAL AND METHODS: The dissection of the posterior region of forearm and hand was carried out, and the anatomical variations were documented. RESULTS: 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. DISCUSSION/CONCLUSIONS: 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.