Fifty cadaver hands were dissected to better delineate the extensor te
ndon anatomy to the little finger. The extensor digitorum communis was
present in 35. Of 15 hands without an extensor digitorum communis, 12
had a junctura present. Three hands lacked both extensor digitorum co
mmunis and juncturae. Transfer of the extensor digiti minimi tendon in
these hands could cause loss of extension to the little finger. Ten h
ands had a direct attachment of the extensor digiti minimi tendon on t
he abductor tubercle. Twenty-two hands had either an attachment of the
extensor digiti minimi on the abductor tubercle, an unbalanced ulnar
slip of the extensor digiti minimi, or both, anatomic factors that cou
ld-in the event of ulnar nerve compression or laceration-cause Wartenb
erg's sign. Twenty-eight hands did not have an anatomic variant of the
extensor that could cause ulnar deviation of the little finger.