Wedge plate inserter/impactor and related methods for use in implanting an artificial intervertebral disc
View Patent ↗A wedge plate inserter/impactor instrument is provided primarily for holding, inserting, repositioning, removing, impacting, extracting, and otherwise manipulating an artificial intervertebral disc having features suitable for being manipulated thereby. A spring-loaded holding pin of the instrument can be used to engage a corresponding hole on the disc and confront the angled surfaces of the disc to enable the holding and manipulation of the disc. A forward wedge extension of the inserter/impactor has upper and lower surfaces that engage inwardly facing surfaces of the disc to hold the baseplates of the disc at a preferred lordosis angle with respect to one another. The instrument can engage the disc from a variety of surgical approach angles.
1. An apparatus for manipulating an artificial intervertebral disc, the apparatus comprising:
a shaft having a bore including a longitudinal axis and a distal end having an extension, the extension including a confronting surface substantially perpendicular to the longitudinal axis of the shaft;
a holding pin having a straight portion and a downwardly bent distal end, the straight portion located partially internal the bore of the shaft along the longitudinal axis and being extendible and retractable along the longitudinal axis of the bore of the shaft, the downwardly bent distal end of the holding pin being perpendicular to the longitudinal axis of the bore of the shaft, the downwardly bent distal end of the holding pin adapted to be received in an engagement hole of said artificial intervertebral disc, wherein the engagement hole has a longitudinal axis perpendicular to the longitudinal axis of the bore of the shaft, and wherein the holding pin is in an extended position along the longitudinal axis of the bore of the shaft when the downwardly bent distal end of the holding pin is received in the engagement hole of said artificial intervertebral disc;
a spring coupled to the holding pin and located internal to at least a portion of the bore of the shaft, the spring configured to bias the straight portion of the holding pin further into the bore of the shaft; and
a flange mechanically coupled to the holding pin, wherein exerting pressure on the flange in a distal direction overcomes the spring-load of the spring to space the holding pin at a distance from the distal end extension of the shaft,
wherein the downwardly bent distal end of the holding pin is prevented from being retracted within the bore of the shaft under the bias of the spring as the downwardly bent distal end of the holding pin abuts the confronting surface of the distal end of the shaft, and
wherein a lower surface of the distal end extension of the shaft prevents the holding pin from upward movement with respect to the shaft distal end.
2. The apparatus according to claim 1 , wherein the artificial intervertebral disc comprises first and second articulating baseplates, and wherein the holding pin engages and disengages a corresponding engagement hole of the first baseplate.
3. The apparatus according to claim 1 , the apparatus further comprising a knob coupled to the shaft, wherein rotation of the knob moves the flange such that the holding pin moves into the extended position, and wherein reverse rotation of the knob moves the flange such that the holding pin moves into a retracted position.
4. The apparatus according to claim 3 , wherein the knob is threaded to the shaft, and interference between threads of the knob and threads of the shaft lock the holding pin in position.