Spinal implants having offsets and hooks
View Patent ↗In an embodiment of the invention, for spinal surgery, there is provided an offset arm system that has angular adjustment capability. In an embodiment, there are provided a hook system that is polyaxially or otherwise movably coupled to a body that receives a spinal rod.
1. A spinal implant, comprising;
an arm portion having a lengthwise direction;
a body portion joined to or integral with said arm portion, said body portion having a through-hole therethrough and having a blind hole, said blind hole intersecting said through-hole, said blind hole having internal, threads;
a setscrew having external threads complementary to said internal threads of said blind hole;
a spinal rod received in said through-hole; and
a saddle element received in said blind hole of said body portion, said saddle element having a vertical axis and being able to rotate around said vertical axis with respect to said body portion, said saddle element contacting said spinal rod and having an underside complementary or at least partially complementary to said spinal rod,
wherein said setscrew urges said saddle element against said spinal rod and said saddle element urges said spinal rod against an internal surface of said through-hole,
wherein said through-hole can accept said spinal rod at a range of angles distributed in a horizontal plane, and
wherein said saddle element is able to occupy a range of angles around said vertical axis of said saddle element corresponding to said range of angles of said spinal rod,
wherein said saddle element comprises a recess in a top surface of said saddle element, said recess having a depth from said top surface,
wherein said implant comprises a control rod secured to said body portion and fitting within said recess in said saddle element, wherein said control rod cooperates with an internal shape of said recess to limit rotation of said saddle element about said vertical axis with respect to said body portion to a range of angles.
2. The implant of claim 1 , wherein said control rod has a diameter that is smaller than said depth of said recess.
3. The implant of claim 1 , wherein said range of angles determined by said control rod and said recess is substantially equal to said range of angles in which said spinal rod can be received in said through-hole.
4. The implant of claim 1 , wherein said through-hole has a wider region transitioning to a narrower central region followed by a wider external region, and has on its bottom surface a flat region.
5. The implant of claim 1 , wherein said saddle element has an exterior having an external taper and said body portion has an interior having an internal taper complementary to said external taper of said saddle element.
6. The implant of claim 1 , wherein said arm portion is cylindrical.
7. The implant of claim 1 , wherein said arm portion fits inside a pedicle screw.