Anterior bone plate system and method of use

Abstract

An anterior bone plate system is provided that promotes osseous fusion and allows subsidence while restricting extension. The bone plate system requires a minimum number of screws for securing the plate onto bone, thus reducing the amount of osseous tissue damage incurred by the bone structures to which they are attached. The system is also simple to use and provides for independent screw placement while incurring minimal soft tissue damage from lateral retraction. A method for implementing the system is also provided.

What is claimed is:  
     
         1 . A bone plate system for the stabilization and rigid fixation of bone segments, comprising: 
 a bone plate having a first surface, a second bone-contacting surface opposed to the first surface, and a channel formed on the first surface extending lengthwise from one end of the plate to an opposite end, the bone plate further including a plurality of apertures extending through the channel, each aperture having a predefined shape and size;    a plurality of screws capable of insertion into bone, each screw having a lower threaded portion at one end and an open screw head at an opposite end, the screw head having a complementary shape and size sufficient to pass through one of the apertures; and    a locking mechanism for securing the bone plate onto the plurality of screws.    
     
     
         2 . The system of  claim 1 , wherein each aperture and each screw head is oblong.  
     
     
         3 . The system of  claim 1 , wherein the second bone-contacting surface includes surface features.  
     
     
         4 . The system of  claim 3 , wherein the surface features are cleats.  
     
     
         5 . The system of  claim 1 , wherein each screw has a self-tapping end extending from the lower threaded portion.  
     
     
         6 . The system of  claim 1 , wherein each screw head includes an upper threaded portion configured to sit proud.  
     
     
         7 . The system of  claim 6 , wherein the locking mechanism includes a locking device configured for placement over the upper threaded portion.  
     
     
         8 . The system of  claim 7 , wherein the locking device is selected from the group consisting of a nut, cam, wedge, and retaining ring.  
     
     
         9 . The system of  claim 1 , wherein the bone plate further includes a flap on each side of the plate extending lengthwise from one end of the plate to the opposite end, each flap further extending over at least a portion of the channel.  
     
     
         10 . The system of  claim 9 , wherein the locking mechanism comprises a notched region on each flap and a pair of diametrically opposed ramps on each screw head, each ramp further including a groove for engagement with the notched region of the flaps when the screw head is rotated 90 degrees.  
     
     
         11 . A bone plate for stabilizing and rigidly fixing bone segments, comprising: 
 a first surface;    a second bone-contacting surface opposed to the first surface;    a channel formed on the first surface extending lengthwise from one end of the plate to an opposite end;    a plurality of apertures extending through the channel, each aperture having a predefined shape and size for insertion of a bone screw; and    a flap on each side of the plate extending lengthwise from one end of the plate to the opposite end, each flap further extending over at least a portion of the channel.    
     
     
         12 . A method for stabilizing and rigidly fixing vertebral bodies in a patient, comprising the steps of: 
 providing an anterior bone plate system comprising: 
 a bone plate having a first surface, a second bone-contacting surface opposed to the first surface, and a channel formed on the first surface extending lengthwise from one end of the plate to an opposite end, the bone plate further including a plurality of apertures extending through the channel, each aperture having a predefined shape and size;  
 a plurality of screws capable of insertion into bone, each screw having a lower threaded portion at one end and an open screw head at an opposite end, the screw head having a complementary shape and size sufficient to pass through one of the apertures; and  
 a locking mechanism for securing the bone plate onto the plurality of screws;  
   inserting each of the screws into a different vertebral body;    placing the bone plate over the screws; and    locking the bone plate to the screws.    
     
     
         13 . The method of  claim 12 , wherein the step of locking the bone plate comprises inserting a locking device over each of the screws.  
     
     
         14 . The method of  claim 12 , wherein the step of locking the bone plate comprises rotating the screws  90  degrees.  
     
     
         15 . The method of  claim 12 , further comprising the step of preparing a pilot hole in each of the vertebral bodies prior to inserting the screws.  
     
     
         16 . The method of  claim 15 , wherein the step of preparing a pilot hole comprises inserting a distraction pin into the selected vertebral body.  
     
     
         17 . The method of  claim 16 , wherein the distraction pin is inserted in the midline of the vertebral body.  
     
     
         18 . The method of  claim 12 , further comprising the step of removing osteophytes and creating a smooth flat surface on the vertebral bodies prior to inserting the screws.  
     
     
         19 . The method of  claim 18 , wherein the step of creating a smooth flat surface on the vertebral bodies further comprises shaving the vertebral bodies to precisely match the width of the bone plate.  
     
     
         20 . The method of  claim 12 , further including the steps of distracting the vertebral bodies and removing a diseased disc therebetween.  
     
     
         21 . The method of  claim 20 , further including the step of placing a graft into an evacuated disc space.