Abstract: An artificial hand having at least one finger and a thumb is provided with drive motor and a gear to open and close the finger and thumb. A gear wheel is secured to each joint where the finger and thumb is connected to the hand proper. A motor driven worm gear meshes with both gear wheels and reversible gears are interposed between the motor and the worm gear, whereby an axially displaceable shaft maintains the interconnection between the drive means and the worm gear.

Abstract: A telescopically adjustable surgical instrument for a distraction apparatus used in performing an elongation osteotomy comprises a rigid support rail having a guide chamber or guide recess and a rigid extension rail axially slidable in said recess. The extension rail has hinged bone connecting plates by means of which the extension rail may be attached to the distal part of a bone. An extension drive mechanism may be releasably connected to the two rails. The instrument is completely implantable. After the distraction, the position of the extension rail is fixed and the drive mechanism may be easily removed.