Abstract: An instrument for inserting an implant between vertebral bodies, including a holder adapted to hold the implant during insertion of the implant between the vertebral bodies, a retractor adapted to retract the holder away from the implant after the insertion, and a guard adapted to prevent the implant from being removed from between the vertebral bodies during the retraction.

Abstract: An instrument for inserting an implant between vertebral bodies, including a holder adapted to hold the implant during insertion of the implant between the vertebral bodies, a retractor adapted to retract the holder away from the implant after the insertion, and a guard adapted to prevent the implant from being removed from between the vertebral bodies during the retraction.

Abstract: Self-locking surgical screw assemblies are described for fastening a medical implant to a bone. The invention also includes combinations of self-locking screws and implants, devices implanted with self-locking screws and related methods which insure the stable attachment of the implant to the bone. Each self-locking surgical screw assembly is comprised of a screw having a non-threaded head affixed to a shank, a threaded portion on the shank, a neck on the shank and a locking device externally affixed to or disposed on the head and/or neck. The locking device lockingly engages the head and/or neck of the screw when the screw is in fastening engagement with the medical implant and the bone.

Abstract: An intervertebral distraction tool has a clamshell head with upper and lower halves, each having a curvate outer surface and a flat inner surface. The distal side of the head is hinged so that the head opens and closes from the proximal side of the head. The hinge is a separating hinge that allows the halves to not only angulate with respect to one another about the hinge axis, but also to vertically separate from one another at the hinge. A distraction separator has decreasing taper at its distal end and a longitudinal bore that accommodates the elongate shaft of the trial so that the separator can be moved longitudinally relative to the shaft. Upon forward movement of the separator, the tapered upper and lower surfaces engage the flat inner surfaces of the head, causing the halves to angulate about the hinge axis of the head, thereby opening the head.

Abstract: An artificial disc having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by a wave washer having a circumferential extent surrounding a central bore. Various wave washer embodiments disclosed include circumferential extents that are ring-shaped, spiral-shaped, straight, bowed, grooved, wavy, thinning, thickening, and slotted. Various central bores disclosed include simple bores and bores that form a curvate socket. Various plate embodiments disclosed include plates having, on inwardly facing surfaces, a flat surface, a circular recess, or a ball-shaped protuberance that is mateable with the curvate socket. The wave washers are disposable between the plates, through various disclosed couplings, so that the plates compress, rotate and angulate freely relative to one another, enabling the artificial disc to mimic a healthy natural intervertebral disc.

Abstract: An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by at least one force restoring element. The preferred force restoring mechanism is a wave washer. In a first embodiment the wave washer is ring-shaped. In a second embodiment the wave washer is spiral-shaped.

Abstract: An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by at least one spring mechanism. The preferred spring mechanism is at least one spirally slotted belleville washer having radially extending grooves. In a preferred embodiment there is a single such belleville which is modified to mount onto a ball-shaped head. The lower plate of this embodiment includes a post extending upwardly from the inner surface of the plate, the post including a ball-shaped head. The modified Belleville washer can be rotatably mounted to the head such that the wider portion of the washer seats against the upper plate. The belleville washer has at least one radially extending groove and at least one spiral slot.

Abstract: An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by at least one spring mechanism. The preferred spring mechanism is an arched strip spring. In a first embodiment there are multiple springs positioned independently about the area of the opposing plates. In a second embodiment there is a single arched strip spring modified to mount onto a ball-shaped head. The lower plate of this second embodiment includes a post extending upwardly from the inner surface of the plate, the post including a ball-shaped head. The spring and post members are flexibly coupled such that the upper and lower plates may rotate relative to one another.

Abstract: An orthopedic spacer device comprising a spacer body having an external surface that includes at least two relative angle designation marks such that a rotational angle of the spacer body relative to a known reference is determinable.

Abstract: An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, coupled to one another by a convex element mounted to one of the plates and maintained against the other plate by a retaining wall and a retaining ring.

Abstract: An orthopedic device set includes a plurality of intervertebral spacer elements, an instrument for holding the spacer elements during the insertion and removal thereof into and out from between adjacent vertebral bones, and a tool which facilitates the loading and unloading of the spacer elements into and out of the instrument. The tool includes a handle and a bifurcated end having a pair of similarly curved tines. The bifurcated end is engageable with each spacer element during the loading and unloading of the spacer element.

Abstract: An intervertebral spacer device includes first and second plate members, each having plate surfaces thereof, the plate members being disposed in a spaced apart relationship such that inner ones of the plate surfaces oppose one another, and external ones of the plate surfaces face in opposite directions. The device includes at least one slotted domed arch strip spring disposed between the inner surfaces of the first and second plate members for counteracting compressive load applied to the external surfaces of the plate members, one of the plate members having a ball-shaped head attached thereto and spaced from the inner surface thereof, and the at least one slotted domed arch strip spring having a central opening including a curvate volume for receiving and holding therein the ball-shaped head.

Abstract: An intervertebral spacer device includes first and second plates having plate surfaces, the first and second plates being spaced from one another with inner ones of the plate surfaces opposing one another and external ones of the plate surfaces facing in opposite directions. The spacer device includes at least one domed arch strip spring disposed between the inner surfaces of the first and second plate members for counteracting compressive loads applied to the external surfaces of the first and second plates. The at least one domed arch strip spring has lateral ends that are coupled with the first plate and a curvate central portion that is maintained adjacent the inner surface of the second plate.

Abstract: An artificial disc having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by a spider spring having a plurality of spring arms extending radially from a central hub. Various spring arm embodiments disclosed include spring arms that are straight, bowed, grooved, wavy, thinning, or thickening; and spring arms with parallel sides, radially outwardly diverging sides, or radially outwardly diverging and curving sides. Various spider spring embodiments disclosed include spider springs with central hubs that are solid, bored, have curvate sockets, or have semispherical protuberances. Various plate embodiments disclosed include plates having, on inwardly facing surfaces, a curvate socket, a semispherical protuberance, a circular recess, or a flat surface.

Abstract: A polyaxial drill guide includes a body, a collet and a stem. The collet includes a collet shaft having distal and proximal ends and a longitudinal bore. The body includes a conical bore having narrow and wide ends. The distal end of the collet shaft rotatably mounts within the narrow end of the conical bore, with the collet shaft extending toward the wide end of the conical bore, such that the collet shaft (and consequently the longitudinal bore) can be angled within the conical bore at a plurality of angles. The stem includes a shaft having distal and proximal ends and a longitudinal bore. The distal end of the stem shaft mounts to the proximal end of the collet shaft such that the longitudinal bores are co-linear and a drill bit can be inserted into and rotated within the longitudinal bores during a drilling procedure.

Abstract: An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by a subassembly including a ball captured in a curvate volume, at least a portion of the curvate volume being formed in a convex element that is maintained against a first plate by a retaining wall and a retaining ring.

Abstract: An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by a spring mechanism. The preferred spring mechanism is a multi-pronged domed spring which is coupled to the upper plate by set screws. The spring includes a socket formed in the peak thereof and mounts onto a ball-shaped head extending outwardly from the lower plate. The spring and post members are thereby flexibly coupled such that the upper and lower plates may rotate relative to one another.

Abstract: An artificial disc having a pair of opposing baseplates, for seating against opposing vertebral bone surfaces, separated by a ball and socket joint that includes a ball compression locked to a post extending from one of the baseplates. The ball is captured within a curvate socket formed in a peak of a convex structure attached to the other of the baseplates. The socket is formed by opposing curvate surfaces, one on the convex structure and one on the other of the baseplates. While the ball angulates freely in the socket, the rotation of the ball in the socket has a limited range due to interference between a protrusion on the convex structure that extends into the socket and a curvate recess on the ball. The ball and socket joint therefore permits the baseplates to rotate relative to one another through a limited range and also angulate relative to one another.

Abstract: An instrument for insertion, implanting, and removing a cylindrical intervertebral spacer member having a deep circumferential groove, including: a shaft having a proximal end and a distal end, said proximal end forming a handle and the distal end forming a spacer member engaging subassembly; said spacer member engaging subassembly including at least one selectively expanding and contracting enclosure into which a central core of the spacer member may be introduced when the engaging subassembly is in the expanded state, and which holds the spacer member so that it cannot move when the selectively expanding and contracting enclosure is rendered into the contracted state; and an actuating mechanism, extending from the proximal end to the distal end, by which the spacer member engaging subassembly may be selectively expanded and contracted.

Abstract: A polyaxial orthopedic device for use with rod implant apparatus includes a screw having a curvate head, a two-piece interlocking coupling element which mounts about the curvate head, and a rod receiving cylindrical body member having a tapered socket into which both the screw and the interlocking coupling element are securely nested. The interlocking coupling element includes a socket portion which is slotted and tapered so that when it is radially compressed by being driven downwardly into the tapered socket in the cylindrical body it crush locks to the screw. The securing of the rod in the body member provides the necessary downward force onto the socket portion through a contact force on the top of the cap portion. Prior to the rod being inserted, therefore, the screw head remains polyaxially free with respect to the coupling element and the body.