Screw

Abstract: A bone plate for stabilizing the anterior column of the spine has a lower curved surface and an upper surface having two intersecting planes in each of which is a screw hole, the axes of the holes being skewed relative to one another. A bone screw used to secure the plate, has a single start buttress thread near the tip and a two start machine thread near the head, the threads being continuous and of constant pitch.

Abstract: A self-tapping screw with improved cutting point includes a head, a screw body, a double cutting point, and a washer. A first thread and a second thread are formed on the screw body. The second thread has the same pitch as the first thread and is formed between the first thread. The second thread has a major diameter which is less than the major diameter of the first thread. The first thread starts at substantially a shoulder and continues to a point of the screw body The second thread starts at substantially the shoulder and continues to the point of the screw body. The shoulder is formed on a bottom of the head. A washer preferably metal with rubber vulcanized thereon is placed under the shoulder of the head. The rubber seals the hole created by the self-tapping screw with improved cutting point. A notch may be included to improve the deburring and drilling ability thereof. The major diameter of the second thread may be increased to equal the major diameter of the first thread near the head to facilitate the automated application of the washer.

Abstract: In one embodiment of the invention, an anterior fixation system (30) includes a plate (31a-31g) defining a plurality of screw holes (34), a number of screws (32) and a number of locking assemblies (33) for fixing the screws (32) to the plate (31a-31g) The system (30) includes two bone screws (32), a fixed angle screw (50) and a variable angle screw (60) Either the fixed or variable angled screws (50, 60) may be implanted with a single plate (31a-31g), and either type of screw (50, 60) may be placed into any of the screw holes (34) along the plate (31a-31g) The several screw holes (34) may be in various patterns (38, 39, 40, 41, 42, 43, 44) The invention further contemplates a locking assembly (33) to lock one or more bone screws (32) within a respective screw hole (34) In one embodiment, the locking assembly (33) includes a washer (90) overlapping one or more screw holes (34), and a locking screw (85) In another embodiment, a locking washer (120) includes cut-outs (128) corresponding to the screw recesses (105), along with a notch (110) and key (129) configuration

Abstract: For a pedicle screw a receiver member is provided for hingedly connecting a screw (2) comprising a threaded shaft portion (3) and a spherical-segment-shaped head (4) on the one hand and a rod (16) on the other hand. In order to improve the stocking costs for screws of different shaft lengths and shaft diameters, the receiver member has a receiver chamber (7) therein, the receiver chamber has a bore (8) at one end thereof for passing the threaded shaft portion (3) followed by an inner hollow spherical-segment-shaped portion (9) for supporting the head of the screw (2) to be received, and an aperture (10) on the side opposite to the bore (8) for inserting the screw (2). Further, a compression member (18) is provided which exerts, in assembled state, a force onto the head such that the head is pressed against the hollow spherical-segment-shaped portion (9). The new receiver member provides that only screws with different screw shafts must be stocked and in operation these screws can be then assembled with the uniform receiver members.