The ape-thumb deformity occurs due to lesion of
Injury to the median nerve at the wrist is much more common than at the elbow. This is due to the superficial position of the nerve at this site.It produces Ape thumb deformity where the thenar muscles are wasted, and the thumb is adducted and laterally rotated.Ref: BD Chaurasia; volume 1; 6th edition
Radial nerve
Median nerve
Ulnar nerve
Musculocutaneous nerve
Upper limb