Patent ID: 7708737

Claim:
An intramedullar distraction device for bone elongation based on the Callotasis phenomenon, which enables mechanical activation by a patient, said device comprising: a ratchet assembly including a ratchet cover, a gear and a long screw which rotates in an amount equivalent to at least one tooth on said gear for each ratchet action; a nail assembly that is rigidly connected to said ratchet assembly, wherein said nail assembly is adapted for installation within a prepared medullar cavity of a long bone, said nail assembly including at least two interconnected metal pieces, wherein rotation of said long screw of said ratchet assembly extends the nail assembly by altering a relative position of said at least two interconnected metal pieces; and a subcutaneous button located at said ratchet assembly for initiating said ratchet action by causing said gear to turn when said button is depressed, said button being activatable by pressure applied on to the skin.