Interconnected Locking Plates for Adjacent Spinal Vertebral Bodies

Abstract

A device for insertion into a gap between adjacent, spaced apart bony elements includes an adjustable length interconnecting member having a distal and a proximal retention plate secured to opposite ends of the interconnecting member. The distal retention plate has a non-rotated position and a plurality of rotated positions. The non-rotated position aligns the distal retention plate with the gap prior to and during insertion of the distal retention plate into the gap. The distal retention plate is rotated after it has exited the gap on a distal side of the gap to prevent its return into the gap. The proximal retention plate is misaligned with the gap so that it cannot enter into the gap. The rotated distal retention plate cooperates with the proximal retention plate to hold bony elements such as adjacent vertebral bodies in a stable relationship to one another when the interconnecting member is shortened.

What is claimed is: 
     
         1 . A device for insertion into a gap between two adjacent bony elements, comprising:
 a distal retention plate having an elongate shaft secured in normal relation thereto;   a proximal retention having an elongate shaft secured in normal relation thereto;   said elongate shaft of said distal retention plate being disposed in telescoping relation to said elongate shaft of said proximal retention plate.   
     
     
         2 . The device of  claim 1 , further comprising:
 each of said retention plates being sufficiently large to span a distance between said adjacent bony elements when rotated after insertion.   
     
     
         3 . The device of  claim 2 , further comprising:
 said distal and proximal plate shafts being secured to one another in telescoping and non-rotating relation to one another.   
     
     
         4 . The device of  claim 3 , further comprising:
 each of said elongate shafts having a non-round transverse cross-section;   said distal retention plate shaft having a non-round lumen that telescopically mates with a non-round transverse cross-section of said proximal retention plate shaft;   whereby rotation of said proximal retention plate effects conjoint rotation of said distal retention plate.   
     
     
         5 . The device of  claim 3 , further comprising:
 each of said elongate shafts having a non-round transverse cross-section;   said proximal retention plate shaft sleeve having a non-round lumen that telescopically mates with a non-round transverse cross-section of said distal retention plate shaft;   whereby rotation of said proximal retention plate effects conjoint rotation of said distal retention plate.   
     
     
         6 . The device of  claim 2 , further comprising:
 each of said elongate shafts having a length sufficient to enable the proximal and distal retention plates to extend beyond said adjacent bony elements.   
     
     
         7 . The device of  claim 2 , further comprising:
 said device having an unrotated position of repose and an infinite plurality of rotated positions relative to said unrotated position of repose.   
     
     
         8 . The device of  claim 7 , further comprising:
 said unrotated position of repose aligning said device with said gap prior to insertion and during insertion of said device into said gap;   said device being in a rotated position after said distal retention plate has exited said gap on a distal side of said gap, but prior to said proximal retention plate entering said gap;   said device when in said rotated position preventing distal-to-proximal or proximal-to-distal displacement of said retention plates into said gap; and   said distal retention plate when in said rotated position cooperating with said proximal retention plate to hold said adjacent bony elements in a stable relationship to one another.   
     
     
         9 . The device of  claim 8 , further comprising:
 said telescoping means enabling retraction of the elongate shafts to thereby enable the proximal and distal retention plates to positively engages the adjacent bony elements   
     
     
         10 . The device of  claim 2 , further comprising;
 a roughened inboard surface formed on each of said distal and proximal retention plates.   
     
     
         11 . The device of  claim 2 , further comprising;
 said proximal retention plate having screw-receiving holes formed therein to enable screws to fasten the proximal retention plate to said adjacent bony elements.   
     
     
         12 . A device for insertion into a gap between two bony elements, comprising:
 a distal retention plate with an affixed elongate shaft;   a proximal retention plate with an affixed elongate shaft;   said distal retention plate shaft being non-round in transverse cross-section and said proximal retention plate shaft being non-round in transverse cross-section and said shafts being disposed in sliding, mating relation to one another;   said elongate shafts having a length sufficient to enable said plates to extend beyond said adjacent bony elements;   said device having an unrotated position of repose and an infinite plurality of rotated positions relative to said position of repose;   said unrotated position of repose aligning said device with said gap prior to insertion and during insertion of said device into said gap;   said device being in a rotated position after said distal retention plate has exited said gap on a distal side of said gap, but prior to said proximal retention plate entering said gap;   said device when in said rotated position preventing distal-to-proximal or proximal-to-distal displacement of said retention plates into said gap;   said distal retention plate when in said rotated position cooperating with said proximal retention plate to hold said adjacent bony elements in a stable relationship to one another;   whereby rotation of said proximal retention plate effects conjoint rotation of said distal retention plate; and   whereby a combined length of said elongate shafts is reduced to enable said proximal and distal retention plates to positively engage said adjacent bony elements.   
     
     
         13 . The device of  claim 12 , further comprising:
 said distal retention plate shaft having a non-round lumen;   said proximal retention plate shaft having a non-round transverse cross-section;   said non-round transverse cross-section of said proximal retention plate shaft being slideably disposed within said non-round lumen of said distal retention plate shaft.   
     
     
         14 . The device of  claim 12 , further comprising:
 said proximal retention plate shaft having a non-round lumen;   said distal retention plate shaft having a non-round transverse cross-section;   said non-round transverse cross-section of said distal retention plate shaft being slideably disposed within said non-round lumen of said proximal retention plate shaft.