A study of anatomical variations of the extensor tendons of the index finger and their significance

Abstract: The anatomical arrangement of the extensor tendons for the fingers is known to be quite variable on the dorsum of the hand. Hundred and one upper limbs from formalin fixed cadavers were dissected meticulously to reveal the tendons of the extensor digitorum (ED), extensor indicis (EI) and extensor digiti minimi (EDM). The variations with respect to the number of extensor tendons for the fingers on the dorsum of the hand were noted. The relationship of the position of EI tendon and the ED-Index finger tendon at the radial styloid and at the metacarpophalangeal joint was noted in each specimen. All the dissected specimens were looked for any anomalous (supernumerary) muscles or tendinous slip on the dorsum of the hand. All these metric and nonmetric parameters have been compared with those available in the literature. Embryological basis of the variations in this region has been discussed. Also findings of surgical importance have been enumerated and their clinical significance has been discussed.