Restoration of opposition.

Opposition is not grasp but a preposition for grasp that involves 3 components of thumb movements: abduction, flexion, and pronation. Thumb opposition is usually lost with paralysis of the thenar muscles innervated by the median nerve. Many opposition transfers have been described that differ in the donor tendon, route of transfer, and method of attachment to the thumb. No one transfer is applicable for every clinical condition, and each transfer has its advantages and disadvantages. Many factors must be evaluated to decide if surgery is likely to be beneficial and then decide on the optimum treatment.