Seal-less self-actuating growing rod systems

A dynamic-seal-less self-actuating growing rod system (100) comprising:

• a. at least one cylindrical static rod (2) with an internal bore comprising a first static end (2a) and a second static end (2b), wherein said second static end (2b) is sealed by at least one cap (3) to define the area enclosed therein as a fluid receptacle shell (4);
• b. at least one piston rod (6), coaxially coupled with said static rod (2) and comprising a first piston end (6a) and a second piston end (6b);
• wherein said second piston end (6b) is disposed within the internal bore of said static rod (2) through said cap (3) and is configured to distract longitudinally out of the static rod (2);
• c. at least one fluid source (8) holding at least one sterile biocompatible fluid at a pre-determined pressure;
• and
• d. at least one fluid transfer port (10) configured to transfer said sterile biocompatible fluid in said fluid source (8) to at least one fluid receptacle (12) at the same pre-determined pressure,
• said system (100) being characterized in that:
• said at least one fluid receptacle (12) is housed within said fluid receptacle shell (4) and is in contact with said second piston end (6b) of said piston rod (6) at a first receptacle end (12a) and is connected to said fluid transfer port (10) at a second receptacle end (12b),
• said at least one fluid receptacle (12) being at least one selected from the group consisting of metal bellows, polymeric bellows, polymeric balloon, polymeric tube and contains the said sterile biocompatible fluid at said pre-determined pressure.