Polyaxial Pedicle Screw Assembly

Abstract

A pedicle fixation assembly and method for assembly comprises a screw head comprising a male bulbous end; a bone fixator component comprising a female concave semi-spherical socket for receiving the screw head; a locking saddle pin for engaging the screw head and the bone fixator component; and a blocker for engaging the screw head and for securing the longitudinal member.

What is claimed is: 
     
         1 . A pedicle screw assembly comprising:
 a screw head comprising a slot and a bottom portion;   a connecting end operatively connected to said bottom portion of said screw head;   a bone fixator component comprising a socket that receives said connecting end;   means for causing engagement of said connecting end to said bone fixator component; and   a blocker that engages said screw head.   
     
     
         2 . The pedicle screw assembly of  claim 1 , wherein a combination of said bottom portion of said screw head with said connecting end form a substantially bulbous body. 
     
     
         3 . The pedicle screw assembly of  claim 1 , wherein said bone fixator component is located completely outside of said screw head. 
     
     
         4 . The pedicle screw assembly of  claim 1 , wherein said bottom portion of said screw head and said connecting end are locked into said socket of said bone fixator component. 
     
     
         5 . The pedicle screw assembly of  claim 1 , wherein said screw head comprises at least one upright end adjacent to said slot. 
     
     
         6 . The pedicle screw assembly of  claim 5 , wherein said screw head comprises:
 a lower base portion adjacent to said at least one upright end; and   an aperture extending from said lower base portion through said connecting end.   
     
     
         7 . The pedicle screw assembly of  claim 2 , wherein substantially bulbous body is rotatable with respect to said socket. 
     
     
         8 . An assembly comprising:
 a slotted screw head comprising a substantially bulbous body extending away from a bottom portion of said slotted screw head;   a hole in said slotted screw head and extending through said substantially bulbous body;   a bone engaging component comprising a socket that cups said substantially bulbous body; and   means for causing outward expansion of said substantially bulbous body.   
     
     
         9 . The assembly of  claim 8 , wherein said bone engaging component is located completely outside of said slotted screw head. 
     
     
         10 . The assembly of  claim 8 , wherein said substantially bulbous body is locked into said socket of said bone engaging component. 
     
     
         11 . The assembly of  claim 8 , wherein said slotted screw head comprises at least one upright end pointing away from said substantially bulbous body. 
     
     
         12 . The assembly of  claim 11 , wherein said slotted screw head comprises:
 a lower base portion adjacent to said at least one upright end; and   an aperture extending from said lower base portion through said substantially bulbous body.   
     
     
         13 . The assembly of  claim 8 , wherein substantially bulbous body is rotatable with respect to said socket. 
     
     
         14 . An assembly comprising:
 a bone engaging component comprising a socket; and   a screw head comprising a stem portion extending from a bottom of said screw head and fits inside said socket.   
     
     
         15 . The assembly of  claim 14 , further comprising means for locking said stem portion inside said socket. 
     
     
         16 . The assembly of  claim 14 , wherein said stem portion is located completely outside of said screw head. 
     
     
         17 . The assembly of  claim 14 , wherein said screw head is rotatable with respect to said bone engaging component. 
     
     
         18 . The assembly of  claim 14 , wherein said screw head comprises:
 at least one upright end positioned opposite to said stem portion;   a lower base portion adjacent to said at least one upright end; and   an aperture extending from said lower base portion through said stem portion.   
     
     
         19 . The assembly of  claim 18 , further comprising a pin dimensioned and configured to fit in said aperture. 
     
     
         20 . The assembly of  claim 14 , wherein said stem portion is expandable.