Occipital plate and system for spinal stabilization

Abstract

An occipitocervical fixation system includes a plate for securing to the occiput and at least one pre-bent rod. The plate includes holes for receiving bone fasteners, and at least one clamping assembly for retaining a portion of a rod. The clamping assembly is selectively pivotable and lockable in place to fix the position of the rod.

1 . An occipital plate assembly comprising: a bone contacting surface, an outer surface, an upper end, a lower end, and at least one hole extending from the bone contacting surface to the outer surface for receiving a bone screw, wherein the plate further includes at least one rod clamping portion on the lower end, the rod clamping portion having a rod-receiving recess with an opening for receiving a spinal rod, the opening being generally directed upwards when the plate is affixed to a patient's occiput.  
     
     
         2 . The occipital plate assembly of  claim 1 , wherein the spinal rod is a pre-bent rod comprising a first section, a second section, and an intermediate section disposed therebetween, wherein the first section and the second section are disposed substantially perpendicular with respect to one another.  
     
     
         3 . The occipital plate assembly of  claim 2 , wherein the second section and the intermediate section are disposed at an angle with respect to one another.  
     
     
         4 . The occipital plate assembly of  claim 3 , wherein the angle is between 40° and 50 °.  
     
     
         5 . The occipital plate assembly of  claim 2 , wherein the pre-bent rod is substantially cylindrical and the second section includes serrations about a portion of its circumference for mating with serrations formed on an inner surface of the recess.  
     
     
         6 . The occipital plate assembly of  claim 5 , wherein the serrations extend from about 90° to about 180° around the circumference of the rod.  
     
     
         7 . The occipital plate assembly of  claim 1 , wherein the plate has a pair of legs extending from a central portion, the legs each including a rod clamping portion having a rod-receiving recess for receiving a spinal rod while the central portion includes the at least one hole for receiving the bone screw.  
     
     
         8 . The occipital plate assembly of  claim 7 , wherein the central portion includes an upper portion having at least one hole for receiving a bone screw, a lower portion having at least one hole for receiving a bone screw, and a grooved portion extending therebetween, the groove portion being flexible to permit the upper portion to be disposed at an angle with respect to the lower portion.  
     
     
         9 . The occipital plate assembly of  claim 1 , wherein the rod clamping portion includes a pivot member and a clamp plate, the clamp plate being pivotable about the pivot member.  
     
     
         10 . The occipital plate assembly of  claim 9 , wherein the clamp plate includes an extension sized and configured to engage an arcuate stepped-in portion formed on the lower end of the plate to limit the amount of pivot between the clamp plate and the plate.  
     
     
         11 . The occipital plate assembly of  claim 9 , wherein the plate includes a hole for receiving the pivot member and a fastener for tightening the clamp plate to the pivot member.  
     
     
         12 . The occipital plate assembly of  claim 9 , wherein the plate includes a rod-receiving first recess and the clamp plate includes a rod-receiving second recess, the first and second recesses forming the rod-receiving recess.  
     
     
         13 . The occipital plate assembly of  claim 12 , wherein the second recess is serrated.  
     
     
         14 . The occipital plate assembly of  claim 1 , wherein the at least one hole includes a bushing to permit polyaxial angulation of the bone screw with respect to the plate.  
     
     
         15 . The occipital plate assembly of  claim 14 , wherein the bushing further includes at least one slot located on a sidewall thereof.  
     
     
         16 . An occipital plate assembly comprising: 
 a plate having a central portion and a pair of supporting arms extending therefrom, the central portion including a plurality of holes extending from a bone contacting surface to an outer surface for receiving a plurality of bones screws to secure the plate to a patient's occiput; and    at least one pre-bent spinal rod wherein the rod has a first section, a second section, and an intermediate section disposed therebetween, the first and second sections being disposed substantially perpendicular with respect to one another;    wherein each of the supporting arms includes a rod-receiving recess for engaging one of the sections of the pre-bent rod.    
     
     
         17 . The occipital plate assembly of  claim 16 , wherein the recess has an opening for receiving the spinal rod, the opening being generally directed upwards when the plate is affixed to the patient's occiput.  
     
     
         18 . The occipital plate assembly of  claim 16 , wherein the second section of the rod and the intermediate section of the rod are disposed at an angle with respect to one another.  
     
     
         19 . The occipital plate assembly of  claim 18 , wherein the angle θ is between 40° and 50°.  
     
     
         20 . The occipital plate assembly of  claim 16 , wherein the pre-bent rod is substantially cylindrical and the second section of the rod has serrations about a portion of its circumference for mating with serrations formed on an inner surface of the recess.  
     
     
         21 . The occipital plate assembly of  claim 20 , wherein the serrations extend from about 90° to about 180° around the circumference of the rod.  
     
     
         22 . The occipital plate assembly of  claim 16 , wherein the central portion includes an upper portion, a lower portion, and a grooved portion extending therebetween, the upper portion including at least one hole for receiving a bone screw, the lower portion including the plurality of holes, and the grooved portion is flexible to permit the upper portion to be disposed at an angle with respect to the lower portion.  
     
     
         23 . The occipital plate assembly of  claim 16 , wherein each of the rod-receiving recesses is formed by a pivot member and a clamp plate, the clamp plate being pivotable about the pivot member.  
     
     
         24 . The occipital plate assembly of  claim 23 , wherein the clamp plate includes an extension sized and configured to engage an arcuate stepped-in portion formed on the outer surface of each leg to limit the amount of pivot between the clamp plate and the plate.  
     
     
         25 . The occipital plate assembly of  claim 23 , wherein each leg further includes a hole for receiving the pivot member and a fastener for tightening the clamp plate to the pivot member.  
     
     
         26 . The occipital plate assembly of  claim 23 , wherein each leg includes a rod-receiving first recess and the clamp plate includes a rod-receiving second recess, the first and second recesses forming the rod-receiving recess.  
     
     
         27 . The occipital plate assembly of  claim 26 , wherein the second recess is serrated.  
     
     
         28 . The occipital plate assembly of  claim 16 , wherein the at least one hole includes a bushing to permit polyaxial angulation of the bone screw with respect to the plate.