Bi-planar persuader
The present disclosure relates generally to surgical instruments for spinal surgery. More specifically, the present disclosure relates to a bi-planar rod persuader for urging a spinal rod into a screw, and methods regarding the same. The bi-planar rod persuader may include an implant holder, which may also include a holding sleeve. A securing foot may be attached to the distal end of the holding sleeve, and the holding sleeve may also include a threaded opening at the proximal end for receiving a stem that drives the securing foot between a first position and second position. The implant holder may also include a threaded part to engage a reduction knob. A handle assembly may also be provided, which may include two pivotally attached arms. A rod hook may be connected to one of the arms and a guide attached to the other of the arms.
1. A medical device adapted to be secured to a screw, comprising:
an implant holder that includes a holding sleeve and a securing foot pivotally attached to a distal end of the holding sleeve, the holding sleeve defining a threaded opening at a proximal end thereof that receives a stem, wherein rotation of the stem in the threaded opening drives the securing foot between a first position and a second position; and
a rod hook moveable in both a first direction and a second direction different than the first direction, whereby movement of the rod hook in the first and second directions is configured to cause the rod hook to urge a spine rod into the screw,
wherein a portion of the securing foot engaging the screw has a known geometry and is complementary to a known geometry of the screw, and
wherein the securing foot is engaged to the screw when in the second position and is disengaged from the screw when in the first position.
2. The medical device of claim 1 , wherein a proximal end of the stem includes a securing cap, and wherein a distance between the securing cap and the distal end of the stem is predetermined to prevent over-tightening or over-loosening of the stem.
3. The medical device of claim 2 , wherein a portion of the stem proximate to the securing cap defines a threaded region.
4. The medical device of claim 3 , wherein the threaded region extends over less than a length of the stem.
5. The medical device of claim 3 , wherein the securing foot is in the first position when the threaded region of the stem and the threaded opening of the holding sleeve are uncoupled.
6. The medical device of claim 3 , wherein the securing foot is in the second position when the stem is rotated about the threaded opening of the holding sleeve.
7. The medical device of claim 1 , wherein securing foot engages only one side of a head of the screw.
8. A medical device for reducing a rod into the head of a screw, comprising:
an implant holder that includes a holding sleeve, a securing foot that extends from a distal end of the holding sleeve, the holding sleeve defining a threaded opening at a proximal end thereof that receives a stem that drives the securing foot between a first position and a second position, the implant holder including a threaded part extending at a predetermined angle from the proximal end of the holding sleeve that is adapted to engage a complementary threaded region of a reduction knob; and
a handle assembly comprising two pivotally attached arms, a rod hook connected to one of the arms and a guide attached to the other of the arms; and
wherein the guide is adapted to slidably engage the threaded part such that the rod hook is moveable in a first direction by threaded interaction of the reduction knob with the threaded part, and wherein pivotal motion of the arms causes the rod hook to be moveable in a second direction different than the first direction.
9. The medical device of claim 8 , wherein the proximal end of the stem includes a securing cap.
10. The medical device of claim 9 , wherein a portion of the stem proximate to the securing cap defines a threaded region.
11. The medical device of claim 8 , wherein the rotation of the stem into the threaded opening of the holding sleeve engages the securing foot to a screw head.
12. The medical device of claim 11 , wherein the portion of the securing foot engaging the screw has a known geometry and is complementary to a known geometry of the screw.
13. The medical device of claim 8 , wherein the distal end of the holding sleeve is defined having three sides, and wherein one side of the three sides has an opening defined therein.
14. The medical device of claim 8 , wherein the predetermined angle of the threaded part of the implant holder is approximately 12°.
15. The medical device of claim 8 , wherein the first direction is defined as substantially parallel along an axis defining the threaded part.
16. The medical device of claim 8 , wherein the second direction is defined as being substantially parallel to an axis approximated by an arc created by the movement of the rod hook.
17. A medical device for reducing a rod into the head of a screw, comprising:
an implant holder that includes a holding sleeve having a proximal end and a distal end, a securing foot pivotally attached to the distal end of the holding sleeve, and a stem that drives the securing foot, the implant holder including a threaded part extending from the proximal end of the holding sleeve that is adapted to engage a complementary threaded region of a reduction knob; and
a handle assembly comprising two pivotally attached arms, a rod hook connected to one of the arms and a guide attached to the other of the arms,
wherein the guide is adapted to slidably engage the threaded part such that the rod hook is moveable by threaded interaction of the reduction knob with the threaded part in a first linear direction, and wherein pivotal motion of the arms causes the rod hook to be moveable in a second arcuate direction, and
wherein rotation of the stem into a threaded opening of the holding sleeve engages the securing foot to the screw head.
18. The medical device of claim 17 , wherein a portion of the securing foot that engages the screw has a known geometry and is complementary to a known geometry of the screw.
19. The medical device of claim 17 , wherein the guide is attached to the rod hook with a pivot screw.
20. The medical device of claim 17 , wherein the first linear direction is defined as substantially parallel along an axis defining the threaded part, the second arcuate direction is defined as substantially parallel along an axis defining an arc that intersects the axis along the first direction.