Implant insertion apparatus and method of use
An apparatus for use with a spinal implant includes a handle structure with a passage. A shaft with a screw thread is moveable within the passage in the handle structure. A pusher block is linked to the shaft, and has a forward surface configured to engage the spinal implant. A screw-threaded clutch member is supported on the handle structure for movement into and out of engagement with the screw thread on the shaft.
1. An apparatus having a longitudinal axis for inserting a spinal implant between vertebrae, the apparatus comprising:
a handle structure having a passage therethrough;
a shaft moveable within the passage;
a pair of paddles, each of the pair of paddles having a proximal end and a distal end, the proximal ends of the paddles connected to the handle structure, and each of the pair of paddles having a stop structure that extends generally away from the longitudinal axis at a location proximate to the distal end, the paddles converging along the longitudinal axis toward the distal ends, wherein at least one of the pair of paddles defines a slot that extends generally parallel to the longitudinal axis;
a pusher block movably coupled with respect to the shaft and positioned between the pair of paddles, the pusher block having a forward surface configured to engage the spinal implant; and
an ejector rod having at least one arm that is configured to slide along the slot, the at least one arm defining a side that faces the distal end and is configured to abut one of the vertebrae when the implant is inserted between the vertebrae, such that the at least one arm defines a distance between the side and the forward surface of the pusher block, wherein the ejector rod is adjustably mounted to the pusher block so as to correspondingly adjust the distance, wherein the ejector rod, the pusher block and the shaft are movable along a direction generally parallel to the longitudinal axis such that the at least one arm slides along the slot, and at least one of the pair of paddles moves away from the other of the pair of paddles as the pusher block moves from the proximal end to the distal end such that a gap is formed between the distal ends, the gap being sized to accommodate passage of the implant between the distal end of each of the pair of paddles.
2. The apparatus of claim 1 , wherein the paddles are flexible, such that as the pusher block moves from the proximal end to the distal end, the implant abuts the flexible paddles and causes at least one of the pair of flexible paddles to flex away from the other.
3. The apparatus of claim 2 , wherein the shaft includes external threads selectively engageable with internal screw threads on a clutch member that is movably mounted to the handle structure such that when the external threads are engaged with the internal screw threads of the clutch member only rotation of the shaft relative to the handle structure results in advancement of the shaft through the passage.
4. The apparatus of claim 1 , wherein both of the pair of flexible paddles flex away from each other as the pusher block moves from the proximal end to the distal end.
5. The apparatus of claim 2 , wherein the pair of paddles is configured as an assembly of multiple springs affixed to a base, the base being located at the proximal end.
6. The apparatus of claim 2 , wherein the pair of paddles is configured as a pair of elongated leaf springs.
7. The apparatus of claim 6 , wherein each of the pair of paddles is configured as an elongated leaf spring that is bowed transversely outward relative to the other from the handle along the longitudinal axis, and converges toward the other at the distal end.
8. The apparatus of claim 1 , wherein the pair of paddles is configured as a unitary spring structure having separately flexible portions.
9. The apparatus of claim 8 , wherein the unitary spring structure includes a tubular base at the proximal end and the separately flexible portions are connected at the tubular base and extend from the tubular base toward the distal end.
10. The apparatus of claim 1 , wherein the pair of paddles is devoid of a hinge.
11. The apparatus of claim 1 , wherein the paddles are biased together at the respective distal ends.
12. The apparatus of claim 1 , wherein the ejector rod comprises a central portion having a central axis and two arms extending from the central portion.
13. The apparatus of claim 12 , wherein the arms are offset from the central axis.
14. The apparatus of claim 12 , wherein the central portion of the ejector rod comprises a plurality of indentations and a groove, the pusher block comprising at least one fastener for engaging the indentations and groove such that the ejector rod is rotatable relative to the pusher block.