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In one embodiment of the invention, an anterior fixation system includes a plate defining a plurality of screw holes, a number of screws and a number of locking assemblies for fixing the screws to the plate. The system includes two bone screws, a fixed angle screw and a variable angle screw, that ar

In one embodiment of the invention, an anterior fixation system includes a plate defining a plurality of screw holes, a number of screws and a number of locking assemblies for fixing the screws to the plate. The system includes two bone screws, a fixed angle screw and a variable angle screw, that are configured to extend through the same screw openings in the fixation plate. The surgeon can select either the fixed or variable angled screws to be implanted with a single plate and can place either type of screw into any of the screw holes along the plate. The fixation plate according to the invention can include several screw holes in various patterns that provide the surgeon with great flexibility in the placement of bone screws depending upon the spinal anatomy and pathology. The invention further contemplates a locking assembly to lock one or more bone screws within a respective screw hole. In one embodiment, the locking assembly includes a washer that is held to the plate by a staked locking screw. The washer includes an outer surface that overlaps one or more screw holes. The washer is initially loosely held to the plate by the locking screw so that various tools and bone screws can be passed through the screw holes. In one embodiment of the washer, the washer includes cut-outs corresponding to the screw holes, along with a notch and key configuration for setting the locking washer in its locked configuration.

대표청구항 ▼

[ What is claimed is:] [1.] A bone fixation system comprising:an elongated plate having a top surface and a bottom surface and defining a plurality of holes between said surfaces, at least one of said plurality of holes including a spherical recess portion adjacent said top surface having a first di

[ What is claimed is:] [1.] A bone fixation system comprising:an elongated plate having a top surface and a bottom surface and defining a plurality of holes between said surfaces, at least one of said plurality of holes including a spherical recess portion adjacent said top surface having a first diameter and defining an opening at said bottom surface having a second diameter less than said first diameter;a first bone engaging fastener having a first elongated shank defining bone engaging threads thereon, a first enlarged head and a first intermediate portion between said shank and said head, said first shank having an outer diameter less than said second diameter so said first bone engaging fastener can be inserted through said at least one hole from said top surface of said plate, said first enlarged head defining a partially spherical surface complementary to said spherical recess of said at least one hole, and said first intermediate portion having a third diameter that is substantially smaller than said second diameter, whereby said first head of said first bone engaging fastener can be pivoted within said recess portion of said at least one hole so that said first bone engaging fastener can assume a plurality of angles relative to said bottom surface of said plate; anda second bone engaging fastener having a second elongated shank defining bone engaging threads thereon, a second enlarged head and a second intermediate portion between said shank and said head, said second shank having an outer diameter less than said second diameter so said second bone engaging fastener can be inserted through said at least one hole from said top surface of said plate, said second enlarged head defining a partially spherical surface complementary to said spherical recess of said at least one hole, and said second intermediate portion having a substantially cylindrical portion with a fourth diameter that is approximately equal to said second diameter, whereby said second head of said second bone engaging fastener cannot be pivoted within said recess portion of said at least one hole so that said second bone engaging fastener can assume a fixed orientation relative to said bottom surface of said plate.