Abstract: The invention is related to a bone screw and a device for osteosynthetic fixation. The bone screw includes a head, a shank, and a collar disposed therebetween. A plate or bone fixation assembly may be provided with at least one bore configured and dimensioned to receive such a bone screw, the bore including a tapered wall portion. When the screw is received in the bore and the collar abuts the tapered wall portion, the screw may be disposed at a variety of angles with respect to the plate and fixed at a selected angle.

Abstract: A bone plate includes an upper surface, a bone-contacting surface, and a plurality of holes extending through the upper and bone-contacting surfaces for receiving bone screws. At least one of the holes includes a protrusion disposed on the bone-contacting surface and at least partially surrounding the hole. The bone plate may define a nominal plate thickness in regions between holes, and the protrusion may define an increased plate thickness that is greater than the nominal plate thickness. A bone plate system including a plurality of bone screws is also disclosed.

Abstract: The invention is related to a fastener and a bone fixation assembly for the internal fixation of vertebral bodies. The bone fastener includes a shank having a longitudinal axis, a head positioned adjacent the top end of the shank and having at least two portions separable in the axial direction. The head includes a bottom portion connected to the shank and a top portion connectable to the bottom portion. The bottom portion defines a socket situated coaxially to the longitudinal axis to accept a driver to rotate the fastener, and the top portion has an exterior with a convex design.

Abstract: The invention is related to a bone screw and a device for osteosynthetic fixation. The bone screw includes a head, a shank, and a collar disposed therebetween. A plate or bone fixation assembly may be provided with at least one bore configured and dimensioned to receive such a bone screw, the bore including a tapered wall portion. When the screw is received in the bore and the collar abuts the tapered wall portion, the screw may be disposed at a variety of angles with respect to the plate and fixed at a selected angle.

Abstract: The invention is related to a fastener and a bone fixation assembly for the internal fixation of vertebral bodies. The bone fastener includes a shank having a longitudinal axis, a head positioned adjacent the top end of the shank and having at least two portions separable in the axial direction. The head includes a bottom portion connected to the shank and a top portion connectable to the bottom portion. The bottom portion defines a socket situated coaxially to the longitudinal axis to accept a driver to rotate the fastener, and the top portion has an exterior with a convex design.

Abstract: A bone plate includes an upper surface, a bone-contacting surface, and a plurality of holes extending through the upper and bone-contacting surfaces for receiving bone screws. At least one of the holes includes a protrusion disposed on the bone-contacting surface and at least partially surrounding the hole. The bone plate may define a nominal plate thickness in regions between holes, and the protrusion may define an increased plate thickness that is greater than the nominal plate thickness. A bone plate system including a plurality of bone screws is also disclosed.