Low profile spinal prosthesis incorporating a bone anchor having a deflectable post and a compound spinal rod

A spine stabilization device comprising:

• a bone screw having a distal end adapted to engage a bone and a proximal end;
• a deflectable post having a distal end and a proximal end;
• the distal end of the deflectable post being connected by a ball-joint to the proximal end of the bone screw wherein the ball-joint allows the deflectable post to pivot and rotate relative to the bone anchor;
• the proximal end of the deflectable post being connected to a first end of a coupling;
• a second end of the coupling being connected by a pivoting joint to a rod.

A spine stabilization device comprising:

• an elongated bone anchor having a distal end and a proximal end;
• a post having a distal end and a proximal end;
• a ball-joint which secures the distal end of the post to the proximal end of the bone anchor such that the post may pivot and rotate relative to the bone anchor;
• a tubular extension of the bone anchor which extends over a distal portion of the post;
• a limit surface associated with the tubular extension housing and positioned to contact the post when the post pivots through a first angle from alignment with the bone anchor;
• and
• wherein the limit surface resists pivoting of said post beyond said first angle.