Grooved slot allowing adjustment of the position of a bone fixation device for osteosynthesis
A grooved slot is provided in a bone fixation device for osteosynthesis that permits adjustment of the bone fixation device relative to the bone, before the bone fixation device is finally fixed to the bone. The grooves are formed on the two longitudinally extending, facing walls of the slot, with the grooves on a first side wall of the slot having a vertical displacement of exactly one-half pitch relative to the grooves on the second, opposite side wall of the slot.
1. An elongated bone fixation device for osteosynthesis, defining a longitudinal axis and configured to receive one or more fasteners in apertures therethrough for positioning the device relative to a bone, at least one fastener having a thread defining a shape and a pitch, the elongated bone fixation device, comprising:
at least one aperture configured as an elongated slot extending through the bone fixation device, said elongated slot configured to receive the at least one fastener from a top of the slot;
said elongated slot including two opposing, grooved parallel side walls and two ungrooved walls enclosing said slot at each end, the grooves on each of said parallel side walls having a shape and a pitch configured to match the shape and pitch of the thread of the fastener, all of said grooves being disposed parallel to each other; and
wherein the grooves on a first of said parallel side walls are vertically displaced one-half of said pitch relative to the grooves on the second, opposite, side wall to permit the bone fixation device to be displaced longitudinally along said slot when the at least one threaded fastener is first engaged into a cortex of a bone through the top of said slot, and to fix the bone fixation device relative to the bone when the fastener is further tightened such that the threads of the fastener are fully engaged with said grooves.
2. The elongated bone fixation device of claim 1 , wherein the bone fixation device is an intramedullary nail.
3. The elongated bone fixation device of claim 1 , wherein the bone fixation device is a bone plate.
4. The elongated bone fixation device of claim 1 , wherein the at least one elongated slot is at least two elongated slots.
5. The elongated bone fixation device of claim 1 , wherein at least one elongated slot is aligned with the longitudinal axis of the bone fixation device.
6. The elongated bone fixation device of claim 1 , wherein at least one aperture is configured as a circular threaded aperture.
7. The elongated bone fixation device of claim 1 , wherein at least one elongated slot is aligned with the longitudinal axis of the bone fixation device.
8. The elongated slot according to claim 7 , wherein all of said grooves are disposed parallel to the longitudinal axis of the bone fixation device.
9. A method for performing osteosynthesis, comprising the steps of:
providing a bone fixation device according to claim 1 ;
placing the bone fixation device into an initial position relative to a bone;
inserting a threaded fastener through the elongated slot into a cortex of a bone;
adjusting the position of the bone fixation device relative to the bone after the inserting step; and
after the adjusting step, tightening the threaded fastener into a locked position relative to the elongated slot to fix the bone fixation device relative to the bone.
10. An elongated slot formed in a bone fixation device for osteosynthesis, and configured to receive one or more fasteners from a top of the elongated slot therethrough for positioning the bone fixation device relative to a bone, at least one fastener having a thread defining a shape and a pitch, the elongated slot, comprising:
two opposing, grooved parallel side walls, the grooves on each of said parallel side walls having a shape and a pitch configured to match the shape and pitch of the thread of the fastener, all of said grooves being disposed parallel to each other;
two ungrooved walls enclosing said slot at each end, wherein said two grooved side walls are longer than the two ungrooved end walls; and
wherein the grooves on a first of said parallel side walls are vertically displaced one-half of said pitch relative to the grooves on the second, opposite, side wall to permit the bone fixation device to be displaced longitudinally along said slot when the at least one threaded fastener is first engaged into a cortex of a bone through the top of said slot, and to fix the bone fixation device relative to the bone when the fastener is further tightened such that the threads of the fastener are fully engaged with said grooves.
11. The elongated slot of claim 10 , wherein the bone fixation device is an intramedullary nail.
12. The elongated slot of claim 10 , wherein the bone fixation device is a bone plate.
13. A device comprising a body for fixation to a bone by threaded screws, the threaded screws having a thread shape and a thread pitch, the body comprising:
at least one slot extending through a thickness of the body in a vertical direction, the slot having a length extending along an axis of the body and a width extending between first and second opposed parallel sidewalls, the first and second sidewalls spaced apart from each other to receive at least one of said threaded screws therebetween, said slot additionally including two ungrooved walls enclosing said slot at each end, wherein said two grooved side walls are longer than the two ungrooved end walls, and the length of the slot is greater than the width to accommodate axial adjustment of the body relative to said at least one threaded screw prior to fully tightening the screw;
wherein each of the first and second sidewalls includes at least two grooves extending parallel to the axis, the grooves each having a groove shape configured to receive the thread shape of a tangential portion of the screw in threaded engagement, and
wherein the grooves of each sidewall are spaced apart in the vertical direction by a vertical spacing equal to the thread pitch, and the grooves of the first sidewall are displaced in the vertical direction one-half of the thread pitch relative to the grooves of the second sidewall.