Devices and methods for spinal compression and distraction

A device for applying a force to a spinal column segment, comprising:

• a body having a first engagement end, said body defining a passage therethrough and a bore intersecting said passage;
• and
• a rack movably received in said passage, said rack having a second engagement end opposite said first engagement end;
• a pinion rotatably received in said bore and in operative engagement with said rack to move said first and second engagement ends in an extend direction and a retract direction;
• and
• a locking mechanism mounted to said body, said locking mechanism having a first position in engagement with said rack locking said first and second engagement end from movement in one of said extend direction and said retract direction while allowing said first and second engagement ends to be moved in the other one of said extend direction and said retract direction, said locking mechanism having a second position allowing said first and second engagement ends to be moved in both said extend direction and said retract direction.

A device for applying a force to a spinal column segment, comprising:

• a body having a first end member, said body defining a passage therethrough and a chamber in communication with said passage;
• a rack moveably received in said passage, said rack having a second end member opposite said first end member;
• a driving mechanism in operative engagement with said rack to move said first and second end members in an extend direction for application of a distraction force and in a retract direction for application of a compression force;
• and
• a lock member positioned in said chamber of said body, said lock member having a lock pin engaged thereto engageable to move said lock member between a first position wherein said lock member engages said rack and a second position wherein said lock member is not engaged with said rack.

A device for applying a force to a spinal column segment, comprising:

• a pair of opposite engagement ends each configured for engagement with a portion of the spinal column segment;
• a mechanism disposed between said pair of opposite engagement ends moveable to vary the distance between said engagement ends;
• a driving mechanism operable to move said opposite ends in an extend direction to apply a distraction force and in a retract direction to apply a compression force;
• and
• a locking mechanism having a first position in engagement with said mechanism such that said opposite ends are not movable in one of said extend direction and said retract direction and is movable in the other one of said extend direction and said retract direction, said locking mechanism having a second position allowing said mechanism to be moved in both said extend direction and said retract direction.