System and method for vertebral body plating

Abstract

A spinal plating system for vertebral fixation includes a plate, a compression screw, multiple fixation members and polyaxially adjustable locking rings. The plate is shaped to conform to the curvature of the spine and the surfaces of the vertebral bodies. The compression screw fits through an insert, and together they are guided by the plate as the screw is driven into one of the vertebrae, producing compression between the adjacent vertebrae. A retaining lip on the plate prevents backout of the compression screw. The polyaxial locking rings can be polyaxially pivoted to attain a desired orientation, and are lockable to the plate to maintain the orientation. The fixation members fit through openings in the polyaxial locking rings and the plate to fix the plate to the vertebrae. Locking the polyaxial locking rings fixes the position of the fixation members relative to the plate, and prevents backout of the fixation members.

1 - 20 . (canceled) 
     
     
         21 . A vertebral plate comprising:
 an elongated opening formed in the plate, the opening having first and second ends and lateral sides;   a ramp disposed at the first end of the opening and extending along the lateral sides of the opening;   a lip disposed at the second end of the opening and extending over a portion of the ramp.   
     
     
         22 . The vertebral plate of  claim 21 , further comprising:
 a screw inserted in the opening, wherein insertion of the screw adjacent the first end causes a screw head thereof to move along the ramp such that at least a portion of the screw head is positioned under the lip to inhibit backout of the screw.   
     
     
         23 . The vertebral plate of  claim 22 , further comprising:
 at least one fixation hole formed in the plate;   a fixation screw inserted in the at least one fixation hole.   
     
     
         24 . The vertebral plate of  claim 23 , further comprising:
 at least one polyaxial ring pivotably placed in the at least one fixation hole to orient the fixation screw with respect to the first vertebra, the at least one polyaxial ring having an outside surface with at least one projection that fits into a matching indentation formed in the at least one fixation hole.   
     
     
         25 . The vertebral plate of  claim 24 , wherein the at least one polyaxial ring has a trilobial shape, the at least one projection includes three projections, and the matching indentation has three indentations. 
     
     
         26 . The vertebral plate of  claim 24 , wherein the at least one polyaxial ring locks the fixation screw and thereby fixes the orientation of the fixation screw with respect to the plate. 
     
     
         27 . The vertebral plate of  claim 24 , wherein the at least one polyaxial ring prevents withdrawal of the fixation screw from the plate. 
     
     
         28 . The vertebral plate of  claim 23 , further comprising:
 at least one second hole formed in the plate; and   a second screw inserted in the at least one second hole.   
     
     
         29 . The vertebral plate of  claim 21 , wherein the plate has a bone apposition side having a longitudinal axis and a transverse axis, and the plate is bent about the transverse axis and curved about the longitudinal axis. 
     
     
         30 . The vertebral plate of  claim 29 , wherein the plate has at least one elongated ridge extending normal to bone apposition side thereof. 
     
     
         31 . The vertebral plate of  claim 28 , wherein the plate has a first segment and a second segment, the first segment having the opening and one of the at least one fixation hole located thereon and the second segment having one of the at least one second hole located thereon. 
     
     
         32 . The vertebral plate of  claim 31 , wherein the first segment and the second segment are connected by a bridge region. 
     
     
         33 . The vertebral plate of  claim 32 , wherein a region of the first segment where the opening is located is narrower in width than another region of the first segment. 
     
     
         34 . The vertebral plate of  claim 22 , further comprising:
 a compression insert non-removeably attached to the plate and configured to receive the screw.   
     
     
         35 . The vertebral plate of  claim 23 , wherein at least one of the fixation screw and the screw insertable in the opening has a cancellous thread near a head of the respective screw and the cancellous thread transitions to cortical thread near a tip of the respective screw. 
     
     
         36 . A vertebral plate comprising:
 an elongated opening formed in the plate;   a ramp including first and second portions that each extend from an outer side of the plate toward a bone apposition side of the plate, wherein when viewed along an axis passing through the opening, the first portion extends in a clockwise direction about the axis and the second portion extends in a counter-clockwise direction about the axis;   a lip extending over a portion of the ramp.   
     
     
         37 . The vertebral plate of  claim 36 , further comprising:
 a screw inserted in the opening, wherein insertion of the screw causes a screw head thereof to move along the ramp such that at least a portion of the screw head is positioned under the lip to inhibit backout of the screw.   
     
     
         38 . The vertebral plate of  claim 37 , further comprising:
 at least one fixation hole formed in the plate;   a fixation screw inserted in the at least one fixation hole.   
     
     
         39 . The vertebral plate of  claim 38 , further comprising:
 at least one polyaxial ring pivotably placed in the at least one fixation hole to orient the fixation screw with respect to a vertebra, the at least one polyaxial ring having an outside surface with at least one projection that fits into a matching indentation formed in the at least one fixation hole.   
     
     
         40 . The vertebral plate of  claim 37 , further comprising:
 a compression insert non-removeably attached to the plate and configured to receive the screw.