Cannulated fastener system
View Patent ↗A cannulated fastener system is provided for orthopedic applications that include attaching bone plates to bone. The bone fastener has a cannulation with an inner shape. One or more screwdrivers is provided with a shaft having a shape that matches the cannulation of the fastener to rotationally fix the fastener to the screwdriver. In addition, the screwdrivers have a cutting blade that begins the drilling of a hole for the bone fastener. The screwdrivers may either be for use with a single fastener or have multiple fasteners loaded within a retaining sleeve for automatic or controlled dispensing.
1. A method of installing a bone screw in bone, comprising:
providing at least a first screw and a second screw, each screw comprising a cannulation;
providing a screwdriver comprising a first end and a second end, a drilling blade disposed on the first end, and a shaft shaped to rotationally engage the cannulations of at least the first screw and the second screw;
rotationally engaging the cannulations of at least the first screw and the second screw with the shaft of the screwdriver;
rotating the drilling blade of the screwdriver against the surface of a bone;
continuing rotation of the drilling blade until the first screw is fully engaged in the bone; and
removing the screwdriver from the cannulation of the first screw after the first screw is securely engaged in the bone while retaining the second screw.
2. The method of claim 1 , wherein the screw has a head portion, said head portion comprising a flange having an underside configured to engage a bone or bone plate surface.
3. The method of claim 1 , wherein the screw has at least one cutting flute for engaging and cutting bone.
4. The method of claim 1 , wherein the screwdriver is disposable.
5. The method of claim 1 , wherein the screwdriver is reusable.
6. The method of claim 1 , wherein the screwdriver further comprises a shoulder on the shaft and a spring having a first end configured to engage the shoulder and a second end configured to engage the head portion of the first screw, the spring further configured to bias the first screw toward the first end of the screwdriver.
7. The method of claim 6 , wherein the screwdriver further comprises a sleeve that provisionally axially retains the screws to the screwdriver.
8. The method of claim 7 , wherein the sleeve is transparent.
9. The method of claim 7 , wherein the sleeve has a lip to maintain the screws until inserted into the bone.
10. The method of claim 1 , wherein the sleeve further comprises legs configured to provisionally axially retain the screws to the screwdriver.
11. The method of claim 1 , wherein the screwdriver has a ratchet system, the ratchet system comprising a sliding member with depressions or protrusions, a sleeve surrounding the intermediate portion of the screwdriver with depressions or protrusions, and a plunger with leg members that engage the depressions or protrusions of the sliding member and sleeve member, wherein the sleeve member has a slot within which the sliding member slides so as to advance the screws for insertion into the bone.
12. The method of claim 11 , wherein the sleeve has a lip disposed at one end, the lip configured to provisionally axially retain the screws to the screwdriver.
13. The method of claim 11 , wherein the sleeve further comprises legs configured to provisionally axially retain the screws to the screwdriver, the legs further configured to allow visualization of screws within the sleeve.