Superelastic bone compression staple
The invention is a staple comprising a bridge member having a spherical top surface and a spherical opposing bottom surface defining a constant thickness between and having a constant thickness and a first pair of a first leg and a second leg and a second pair of a first leg and a second leg where the first and second pair of legs are spaced apart along the axis and are joined to the bridge member.
1. A staple, comprising:
a superelastic material and having a bridge member having a top surface which includes a top surface area and an opposing bottom surface defining a constant thickness between for at least 90% of the top surface area, and the bridge member having an axis along a length between a first end and a second end and a first curve which is a portion of a circle or an ellipse along the axis and
at least one pair of legs where the legs are straight and have a polygonal configuration in cross-section with rounded edges and with a short side having a length n and a longer side having a length of at least 2n, the configuration having five sides, and the legs are spaced apart along the axis and are joined to the bridge member by corner extensions which extend directly from the bridge member such that the bridge member top surface flows into a surface of each of the legs to allow the opposing bottom surface of the bridge member to sit flush in a bone.
2. A staple as set forth in claim 1 , wherein the bridge member has a second curve transverse to the axis which is a portion of a circle or an ellipse.
3. A staple as set forth in claim 2 , wherein said first curve is a portion of a circle and the second curve is a portion of a circle, the portions having different diameters.
4. A staple as set forth in claim 2 , wherein said first curve is a portion of a circle and the second curve is a portion of a circle, the portions having the same diameters.
5. A staple as set forth in claim 1 , wherein the staple has between two and six legs.
6. A staple as set forth in claim 1 , wherein the staple has four legs placed at corners of a rectangle and the bridge includes a recess between the extension and the legs flow through the extensions into the bridge from an inwardly curved recess in the ends of the bridge member.
7. A staple as set forth in claim 1 , wherein the superelastic material is Nitinol.
8. A staple as set forth in claim 1 , wherein the bridge member further includes a fenestration.
9. A staple as set forth in claim 1 further comprising a first pair of a first straight leg and a second straight leg joined to the bridge member by a first corner extension and a second corner extension which flow smoothly into the first leg and the second leg from an inwardly curved recess in the first end of the bridge member along the axis, and a second pair of a first straight leg and a second straight leg joined by a first corner extension and a second extensions which flow smoothly into the first leg and the second leg from an inwardly curved recess in the second end of the bridge member and wherein each of the first and second leg of the first pair of legs and of the second pair of legs include an edge surface joined in a smooth uninterrupted contiguous surface through a surface of a corner extension with the top surface of the bridge member.
10. A staple as set forth in claim 9 , wherein two of the pair of first legs and the second legs have a surface which includes an engagement feature.
11. A staple as set forth in claim 10 , wherein the engagement feature is a plurality of ridges.
12. A staple as set forth in claim 9 , wherein the polygonal configuration is a pentagon.