Bone and tissue lengthening device

A device insertable in the medullar canal of a bone for lengthening the bone and tissue in a human or animal by incrementally extending the distance between discrete portions of the bone which are separated into a proximal portion and a distal portion to permit continued growth between the separated portions comprising:

• an intramedullary nail having a distal portion and a proximal portion;
• the proximal portion of the nail being securable within the medullar canal of the bone at the proximal end of the bone;
• the distal portion of the nail being securable within the medullar canal of the bone at the distal end of the bone;
• a hydraulic cylinder connected to the proximal portion of the nail;
• a piston connected to the distal portion of the nail and movable in the cylinder;
• a supply of operating fluid, in communication with the cylinder;
• a shock absorbing element operatively engagable with both the piston and the cylinder;
• and
• mechanism for permitting limited reciprocal lost motion in the direction of movement of the piston between the piston and the cylinder buffered by the shock absorbing element to permit the distal portion of the femur to move and vibrate slightly relative to the proximal portion to stimulate bone growth between the separated portions of the bone.

A device insertable in the medullar canal of a bone for lengthening the bone and tissue in a human or animal by incrementally extending the distance between discrete portions of the bone which are separated into a proximal portion and a distal portion to permit continued growth between the separated portions comprising:

• an intramedullary nail having a distal portion and a proximal portion;
• the proximal portion of the nail being securable within the medullar canal of the bone at the proximal end of the bone;
• the distal portion of the nail being securable within the medullar canal of the bone at the distal end of the bone;
• a hydraulic cylinder connected to the proximal portion of the nail;
• a piston connected to the distal portion of the nail and movable in the cylinder;
• a supply of operating fluid in communication with the cylinder;
• racheting mechanism between the piston and cylinder to limit their relative movement and that of the bone portions to which they are secured to one direction;
• and
• mechanism responsive to depressurization of the operating fluid for releasing the ratcheting mechanism to permit the piston to reverse direction relative to the cylinder.