Fixation system with multidirectional bone supports
View Patent ↗A fixation system includes a plate intended to be positioned against a bone, a plurality of bone screws for securing the plate along a non-fractured portion of the bone, and a plurality of bone pegs which extend from the plate and into bone fragments of the fracture to provide a supporting framework. The pegs can be oriented at various angles relative to an axis normal to be lower surface of the plate. For each peg, once the peg has been appropriately positioned within the peg hole, a set screw is threaded into the peg hole and tightened, thereby securing the peg in the selected orientation.
1. A fracture fixation system, comprising:
a) a substantially rigid plate having a plurality of holes adapted to individually receive bone supports therein, said holes having an upper portion and a lower portion, said upper portion having a first internal thread, and said lower portion having a radius of curvature;
b) a plurality of bone supports each having a head and a shaft, said shaft sized to be received through said holes, and said head having a lower surface with substantially a same radius of curvature as said lower portion of said holes and said head including two sets of pin slots, each set of pin slots defining a diameter of said head, and said diameters being transverse to each other;
c) a plurality of set screws each having a body including a second thread rotationally engageable with said first thread, a lower ball portion sized to be received in said socket of one of said plurality of bone supports such that each said set screw and its respective bone support are adapted to articulate relative to each other by movement of said socket portion about said ball portion, and a proximal rotational engagement means for permitting a rotational force to be applied to said set screw;
d) two pins extending through said ball portion of said set screw, each said pin permitted to rotate through one of said set of pin slots about two transverse axes,
wherein when said bone supports are provided into respective holes, each said bone support may be positioned at a plurality of angles relative to an axis normal to a lower surface of a portion of said plate surrounding a respective hole, and once so positioned, respective set screws when threaded into said upper portions of said holes fix said bone supports at their respective angles.
2. A fracture fixation system according to claim 1 , wherein:
when said bone supports are fixed at their respective angles, said bone supports are adapted to provide a framework for supporting fractured bone fragments, said bone supports of said framework defining a plurality of non-parallel axes.
3. A fracture fixation system according to claim 1 , wherein:
said holes are closely spaced in a linear or curvilinear arrangement.
4. A fracture fixation system according to claim 1 , wherein:
said fixation plate has a body portion and a head portion angled relative said body portion.
5. A fracture fixation system according to claim 4 , wherein:
said body portion and said head portion are configured in a T-shape.
6. A fracture fixation system according to claim 1 , wherein:
said body portion includes at least one non-threaded screw hole.
7. A fracture fixation system according to claim 1 , wherein:
said lower portion of said hole has a spherical radius of curvature.
8. A fracture fixation system according to claim 1 , wherein:
said lower portion of each of said holes defines a surface having a relatively high coefficient of friction.
9. A fracture fixation system according to claim 1 , wherein:
an outer surface of said head of each of said bone supports has a surface having a relatively high coefficient of friction.
10. A fracture fixation system according to claim 1 , wherein:
said plurality of angles is any angle within a predefined range of angles.
11. A fracture fixation system according to claim 1 , wherein:
said shaft of at least one of said bone supports is non-threaded.
12. A fracture fixation system, comprising:
a) a substantially rigid plate having a plurality of holes adapted to individually receive bone supports therein, said holes having an upper portion and a lower portion, said upper portion having a first internal thread, and said lower portion having a substantially spherical radius of curvature;
b) a plurality of bone supports each having a head portion and a shaft portion, said shaft portion sized to be received through said holes, and said head portion having a portion with an outer surface having substantially a same substantially spherical radius of curvature as said lower portion of said holes, and said head portion defining an upper concave socket and including two sets of pin slots, each set of pin slots defining a diameter of said head, and said diameters being transverse to each other; and
c) a plurality of set screws each having a body including a second thread rotationally engageable with said first thread, a proximal rotational engagement means for permitting a rotational force to be applied to said set screw, and a lower ball portion sized to be received in said socket of one of said plurality of bone supports such that each said set screw and its respective bone support are adapted to articulate relative to each other by movement of said socket portion about said ball portion, said ball portion of said set screw is provided with two pins extending therethrough, said pins being transverse to each other, wherein each said pin is permitted to rotate through one of said set of pin slots about two transverse axes,
wherein when said bone supports are provided into respective holes, each said bone support may be positioned at a plurality of angles relative to an axis normal to a lower surface of said plate, and once so positioned, respective set screws when threaded into said upper portions of said holes fix said bone supports at their respective angles.
13. A fracture fixation system according to claim 12 , wherein:
for each said bone support, said socket portion of said bone support captures said ball portion of one of said set screws.
14. A fracture fixation system according to claim 13 , wherein:
said socket portion of said bone support includes slots at which said socket portion is adapted to expand to receive said ball portion of said one of said set screws.
15. A fracture fixation system according to claim 12 , wherein:
said shaft of at least one of said bone supports is threaded.
16. A fracture fixation system according to claim 12 , wherein:
said plate includes at least one screw hole.
17. A fracture fixation system according to claim 12 , wherein:
said plate is a T-shaped plate having a body portion and a head portion angled relative to said body portion, said holes being provided in said head portion.