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 intervertebral spacer has curvate upper and lower rough surfaces that stimulate bone growth and is formed from a porous material that facilitates bone growth thereinto. The spacer has a plurality of smooth linear grooves to facilitate insertion of the spacer into an intervertebral space using a spacer insertion tool that has a scissor-style body. Each of the insertion tool's arm's heads has an inner surface having a pair of smoothed linear protrusions that fit within the linear grooves of the spacer when the heads are closed about the spacer. When the spacer is held, spaces are present between the spacer's rough surfaces and the heads' inner surfaces so that when the protrusions are longitudinally slid from the grooves to leave the spacer in the intervertebral spacer, the rough surfaces are not disturbed.

Abstract: An orthopedic device set, including: a plurality of intervertebral spacers elements, each spacer element having a cylindrical shape and an annular groove formed therein, each spacer element further having a different axial thickness from each other spacer; and an instrument for holding each of the intervertebral spacer elements during the insertion and removal thereof into and out from between adjacent vertebral bones; the instrument comprising a shaft having a distal end, a spacer element holding structure formed at the distal end, which spacer element holding structure can hold the spacer at the annular groove thereof.

Abstract: A porous metal intervertebral spacer having at least one angled through hole extending from the side of the implant to a surface which interfaces with a vertebral body end plate such that an interference screw may be driven through the implant and into the bone, thereby securing the implant from undesired motion. In particular, the through holes are tapered to receive a screw and coupling element therethrough such that once fully seated, the screw is locked to the implant by virtue of a coupling element-through hole mutually tapered nesting. The head of the screw is round, as is the interior of the coupling element, thereby allowing the screw to be inserted at various angles relative to the hole without interfering with the proper seating of the coupling element in the through hole.

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: A surgical treatment for restoring proper anatomical spacing and alignment to vertebral bones including: determining an angular misalignment associated with adjacent vertebral bones; sequentially inserting and removing a series of progressively wider cylindrical spacer elements into the corresponding intervertebral space between the adjacent vertebral bones until the proper anatomical spacing between the adjacent vertebral bones is restored; for each intervertebral space, inserting a diametrically tapered cylindrical porous spacer element into the intervertebral space between the corresponding adjacent vertebral bones; rotating the diametrically tapered cylindrical porous spacer element such that the rotational orientation of the tapered cylindrical porous spacer element introduces the appropriate counter offset to the intervertebral space of the previously misaligned scoliotic vertebral bones, thereby restoring the proper anatomical alignment of the vertebral bones; and stabilizing the adjacent vertebral bon

Abstract: An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated a spring mechanism. The preferred spring mechanism is a domed arched strip 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 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 intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated a spring mechanism. The preferred spring mechanism is a slotted domed arch strip 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 intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated a spring mechanism. The preferred spring mechanism is a slotted partial circular domed arch strip 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 intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated 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 intervertebral disc having a pair of opposing plate members for seating against opposing vertebral bone surfaces, separated by a spring mechanism. The preferred spring mechanism is at least one spirally slotted belleville washer having radially extending grooves. One plate member has a centrally located ball-shaped protrusion that is rotatably coupled in a central socket in the narrow end of the belleville washer, and the wide end of the belleville washer is held against the other plate member by a shield with rivets. Therefore, the disc assembly will not come apart under tension loads applied to the plate members, and the location of the ball joint coupling provides the disc assembly with a centroid of motion that is centrally located between the vertebral bone surfaces, both causing the disc assembly to behave similarly in these respects to a healthy natural intervertebral disc.

Abstract: An artificial intervertebral disc having a pair of opposing plate members for seating against opposing vertebral bone surfaces, separated by a spring mechanism. The preferred spring mechanism is at least one spirally slotted belleville washer having radially extending grooves. The preferred attachment device for securing each plate member to a vertebral bone surface is a convex metal mesh that is laser welded at its perimeter to the plate member. The metal mesh deflects as necessary during insertion of the artificial intervertebral disc between vertebral bodies, and, once the artificial intervertebral disc is seated between the vertebral bodies, deforms as necessary under anatomical loads to reshape itself to the concave surface of the vertebral endplate. The metal mesh therefore provides superior gripping and holding strength upon initial implantation and an osteoconductive surface through which the vertebral bone may ultimately grow.

Abstract: An artificial disc 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, and in some embodiments the belleville washer is also radially thinning or thickening. Various illustrated embodiments use two washers or one washer. For double washer embodiments, the wide ends of the washers seat against respective opposing plates, in some embodiments each being maintained thereagainst by a retaining wall and ring or a circular recess and retaining shield. For single washer embodiments, the narrow end of the washer can be modified to have a curvate socket for rotatably mounting onto a semispherical protuberance extending from one of the plates.

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 spiral-shaped radially diminishing amplitude wave washer.

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 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 space distraction and implantable device assembly provides sequentially axially wider spacers that are to be sequentially inserted into and removed from an intervertebral space to widen the space until a desired anatomical spacing of the adjacent vertebral bones is restored. The set of spacers includes a porous spacer that is as wide as the spacer that restores the desired anatomical spacing. The porous spacer can therefore be left implanted in the intervertebral space to promote fusion of the adjacent vertebral bones.

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 surgical treatment for distracting vertebral bodies to their proper anatomical spacing including sequentially inserting and removing a series of progressively wider cylindrical spacer elements into the intervertebral space between adjacent vertebral bones until the distance between the vertebral bones is anatomically appropriate.