Pollicization (or pollicisation) is a hand surgery technique in which a thumb is created from an existing finger.
[1][2] During pollicization the index finger metacarpal bone is cut and the finger is rotated approximately 120 to 160 degrees and replaced at the base of the hand at the usual position of the thumb.
If the thumb is congenitally absent other tendons from the migrated index finger may be shortened and rerouted to provide good movement.
The presence of an opposable thumb is considered important for manipulation of most objects in the physical world.
Children born without thumbs often adapt to the condition very well with few limitations, so the decision to proceed with pollicization lies with the child's parents with the recommendation of their surgeon.