Bone and tissue lengthening device

A device for lengthening bone and tissue and for fracture fixation in a human or animal by incrementally extending the distance between discrete separated portions of the bone 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 implantable operating fluid in communication with the cylinder;
• a shock absorbing element operatively engagable with both the piston and the cylinder;
• means to permit limited lost motion between the piston and the cylinder against the shock absorbing element in the direction of movement of the piston to stimulate bone growth between the separated portions of the bone;
• and
• a removable slotted tip and releasable securing means for securing the tip to the distal portion of the nail.

A device for lengthening bone and tissue and for fracture fixation in a human or animal by incrementally extending the distance between discrete separated portions of the bone 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 implantable operating fluid in communication with the cylinder;
• ratcheting 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;
• mechanism to permit the piston to reverse directions relative to the cylinder when the pressure of the operating fluid is released;
• and
• a removable slotted tip and releasable securing means for securing the tip to the distal portion of the nail.

A device for the fixation of a bone in a human or animal, which bone is fractured and separated into a distal end and a proximal end, the device comprising:

• a distal elongate member being securable within the medullary canal of the bone at the distal end of the bone;
• a proximal elongate member being securable within the medullary canal of the bone at the proximal end of the bone;
• a coupling mating the distal and proximal members to form an intramedullary nail having a maximum length which permits relative longitudinal motion between the distal and proximal members, the coupling being responsive to longitudinal compression to shorten the length of the formed nail;
• and
• a buffering member disposed within the coupling between the distal and proximal members to permit lost motion to take place between the distal and proximal members, thereby facilitating continued growth between the separated portions of the bone.