Foucher index pollicization. A, Proposed skin incisions providing a large dorsal flap and a distally based palmar flap, which provide a more weblike fold. B, Metacarpal head rotated into flexion and fixed into the metacarpal base with a bone anchor. C, New thumb balanced by tendon transfers; adduction is provided by the extensor indicis communis (EIC), second volar interosseous muscle (2nd VI), and adductor pollicis (not shown), and abduction is provided by extensor indicis proprius (EIP) and first dorsal interosseous muscle (1st DI). D, Sutured skin flaps showing weblike space between new thumb and middle finger and circular scar prevention by the radially based Z-plasty. E-H, New thumb at 3 months postoperatively. (E, From Foucher G, Medina J, Lorea P, Pivato G: Principalization of pollicization of the index finger in congenital absence of the thumb, Tech Hand Upper Extr Surg 9:96, 2005.) SEE TECHNIQUE 19.19.