Bone fixation plate

Abstract

An apparatus for reducing the profile of a bone fixation plate while preventing backing out of screws is disclosed. The plate has at least two openings though which two screws can pass through bony tissue. The apparatus includes at least one section of relief and sections of engagement. As the screw is tightened, it will begin to lag the plate to the bone. When the screw head interferes with the plate at the interference point, there is a slight resistance that insertion forces can overcome. When the screw is advanced further, it snaps into the sliding fit area and is allowed to move freely. The forces that cause the screw to back out from the plate are preferably not strong enough to pass the screw head back past the interference section. At least one of the two openings is configured as an elongated slot to allow the screw to translate in the slot. It may be desirable to include a set screw to help prevent backout.

What is claimed is: 
     
         1 . A bone fixation system comprising:
 a plate including at least one elongated opening extending along a longitudinal axis, the plate further including a plurality of openings, wherein each opening contains alternating sections of engagement and relief; and   a plurality of fasteners each configured to be received in one of the plurality of openings;   wherein the elongated opening is configured to securely receive a drill guide.   
     
     
         2 . The bone fixation system of  claim 1 , wherein the at least one elongated opening is configured with threads. 
     
     
         3 . The bone fixation system of  claim 2 , wherein the threads are configured to receive a threaded tip. 
     
     
         4 . The bone fixation system of  claim 1 , wherein the elongated opening allows rotational movement of the drill guide without releasing the drill guide from the plate. 
     
     
         5 . The bone fixation system of  claim 1 , wherein the plurality of openings includes an a superior pair openings disposed laterally on the plate and an inferior pair of openings disposed laterally on the plate. 
     
     
         6 . The bone fixation system of  claim 1 , wherein each of the plurality of openings includes an interference region. 
     
     
         7 . The bone fixation system of  claim 6 , wherein each of the plurality of openings have a partially spherical curvature. 
     
     
         8 . The bone fixation system of  claim 7 , wherein each of the plurality of fasteners comprises a head capable of engaging with and passing through the interference region. 
     
     
         9 . The bone fixation system of  claim 8 , wherein the at least one fastener comprises at least one slit located on the fastener to permit outward expansion of the head. 
     
     
         10 . The bone fixation system of  claim 9 , further comprising a locking screw capable of being received in a receptacle formed in the head of the at least one fastener. 
     
     
         11 . A bone fixation system comprising:
 a plate including a plurality of openings including a first pair of openings, a second pair of openings, and a third pair of openings, the plate further including a first elongated opening extending along a longitudinal axis, and a second elongated opening extending along the longitudinal axis; and   a plurality of fasteners, each of the plurality of fasteners configured to be received in one of the plurality of openings,   wherein each of the first elongated opening and the second elongated opening is configured to securely engage a drill guide, wherein the drill guide is capable of receiving a drill for drilling a hole through bone.   
     
     
         12 . The bone fixation system of  claim 11 , wherein the first and second elongated openings are configured with threads. 
     
     
         13 . The bone fixation system of  claim 12 , wherein the threads are configured to receive a threaded tip. 
     
     
         14 . The bone fixation system of  claim 11 , wherein the first and second elongated openings allow rotational movement of the drill guide without releasing the drill guide from the plate. 
     
     
         15 . The bone fixation system of  claim 11 , wherein the first pair of openings are disposed on a superior end of the plate, the second pair of openings are disposed in a middle region of the plate, and the third pair of openings are disposed on an inferior end of the plate, the first elongate opening is disposed between the first pair of openings and the second pair of openings, and the second elongate opening is disposed between the second pair of openings and the third pair of openings. 
     
     
         16 . The bone fixation system of  claim 11 , wherein each of the plurality openings includes an interference region. 
     
     
         17 . The bone fixation system of  claim 16 , wherein each of the plurality of openings have a partially spherical curvature. 
     
     
         18 . The bone fixation system of  claim 17 , wherein each of the plurality of fasteners comprises a head capable of engaging with and passing through the interference region. 
     
     
         19 . The bone fixation system of  claim 18 , wherein the at least one fastener comprises at least one slit located on the fastener to permit outward expansion of the head. 
     
     
         20 . The bone fixation system of  claim 19 , further comprising a locking screw capable of being received in a receptacle formed in the head of the at least one fastener.