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 belleville washer having radially extending grooves. In a preferred embodiment there is a single such belleville washer 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.

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 washer 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.

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 spaced concentric grooves. In a preferred embodiment there is a single such belleville washer 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.

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. A first plate of this embodiment includes a post extending upwardly from the inner surface of the plate, the post including a ball-shaped head. The post is designed to flexibly support a slotted belleville washer, which can be selectively mounted to the head such that the wider portion of the washer seats against the second plate. Compression of the assembly causes a deflection of the slotted belleville washer. The slotted belleville washer of this invention has a radially varying thickness which permits the load deflection profile to mimic that of the natural cartilage which is being replaced.

Abstract: A femoral stem for use with an artificial hip joint assembly having helical cuts formed in the shaft thereof. The helical cuts form a restoring force spring-like shock absorbing geometry which permits the rigid metal material to grossly conform to the elastic modulus of the patient's bone. This femoral stem reduces the shock loading and attending pain associated with activities, such as standing, walking, and descending stairs, which often plague hip replacement patients.

Abstract: A screw and coupling element assembly for use with an orthopedic rod implantation apparatus includes a screw with a head and a shaft extending from the head, a coupling element with a seat within which the head is seatable such that the shaft protrudes from the coupling element, and a locking element mateable with the coupling element and when mated is selectively movable through a plurality of positions including unlocked and locked positions. When in the unlocked position, the locking element presents a rod-receiving channel and the head is movable in the seat such that the shaft is directable in a plurality of angles relative to the coupling element. When in the locked position, a rod disposed within the rod-receiving channel is fixed relative to the coupling element and the head is immovable in the seat such that the shaft is fixed at an angle relative to the coupling element.

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 belleville washer having radially spaced concentric grooves. In a preferred embodiment there is a single such belleville washer 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.

Abstract: A screw and coupling element assembly for use with an orthopedic rod implantation apparatus includes a screw that has a head and a shaft that extends from the head, a coupling element that has a seat within which the head can be seated such that the shaft protrudes from the coupling element, and a locking element that can be mated with the coupling element and that thereafter can be selectively moved through a plurality of positions including an unlocked position and a locked position. When the locking element is in the unlocked position, the locking element presents a rod-receiving channel and the head is movable in the seat such that the shaft can be directed in a plurality of angles relative to the coupling element. When the locking element is in the locked position, a rod disposed within the rod-receiving channel is fixed relative to the coupling element and the head is immovable in the seat such that the shaft is fixed at an angle relative to the coupling element.

Abstract: An orthopedic device including a longitudinal plate assembly having an adjustable length and two ends. Each of the ends includes a feature that can be used to couple the end to a body structure, such as, for example, a vertebral bone. Preferably, the assembly includes two longitudinal plates that can translate longitudinally with respect to one another through a plurality of positions and be secured with respect to one another at one of the positions, thereby enabling the length of the assembly to be adjusted. Inasmuch as the length of the plate assembly can be adjusted, the surgeon can set the length to the most clinically appropriate length for effective coupling of the plate assembly to the body structure.

Abstract: An instrument for inserting and removing an intervertebral spacer into and out from an intervertebral space between adjacent vertebral bones, the spacer having a trunk portion having a longitudinal axis and flange portions at each longitudinal end of the trunk, the instrument including: a shaft having a proximal end and a distal end; the proximal end including a handle; and a holding structure provided at the distal end, which holding structure includes an enclosure within which the trunk of the spacer may be selectively introduced and maintained therein, the holding structure having an opening leading to the enclosure and through which opening the trunk of the spacer may be selectively passed to when forced therethrough.

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: An orthopedic device including a longitudinal plate assembly having an adjustable length and two ends. Each of the ends includes a feature that can be used to couple the end to a body structure, such as, for example, a vertebral bone. Preferably, the assembly includes two longitudinal plates that can translate longitudinally with respect to one another through a plurality of positions and be secured with respect to one another at one of the positions, thereby enabling the length of the assembly to be adjusted. Inasmuch as the length of the plate assembly can be adjusted, the surgeon can set the length to the most clinically appropriate length for effective coupling of the plate assembly to the body structure.

Abstract: A polyaxial locking cervical screw and plate assembly for immobilization of cervical bones, via fixation to surfaces thereof, including a plate, having a pair of elongated tapered holes in the top and bottom thereof, into which holes elongated coupling elements and screws may be inserted. Each coupling element has an equivalent taper which matches the taper of the holes in the plate, and an interior semi-spherical curvate surface in which the curvate head of the screw may be polyaxially mounted. The coupling elements are initially disposed in the holes in the plate such that they may slide axially therein. The bone screws are inserted through the respective coupling elements until the heads thereof enter the curvate volumes thereof. Once the head is fully seated in the coupling element, advancement of the screw causes the coupling element to crush lock to the plate and to the head of the screw.

Abstract: A polyaxial orthopedic device for use with rod implant apparatus which includes a screw having a head, a tubular body having holes in the top, side and bottom therof, and a rod coupling element. The head of the screw is disposed in the body with the shaft of the screw extending out the bottom hole, such that the body and the screw may initially rotate relative to one another. The rod coupling element has a ball shaped end which seats in the body with the remainder of the rod coupling element extending out of the side hole of the body, such that the rod coupling element and the body are initially polyaxially coupled relative to one another. The ball end of the rod coupling element is disposed on top of the head of the screw. A set screw is provided in the top of the body, the tightening of which causes the ball, head, and body to be crush locked together, thereby preventing further relative motion.

Abstract: A polyaxial orthopedic device for use with rod implant apparatus includes a screw having a curvate head, a cross bar mounting element having a socket into which the head of the screw is initially polyaxially nested. The cross bar mounting element further includes a vertical split which permits the socket to be expanded or compressed via the application of a corresponding force directed at the split. The cross bar mounting element further includes a pair of upwardly extending members which define a trough into which a cross bar element is positioned. The cross bar element includes features which permit the secure fixation of a rod thereto, as well as a selectively slideable element, such as a nut, which may be tightened to apply the compressive force necessary to compress the interior volume onto the head of the screw, thus locking the assembly in place.

Abstract: A polyaxial orthopedic device for use with rod implant apparatus includes a screw having a curvate ball top, a polyaxial head member having a socket into which the head of the screw is initially polyaxially nested, a vertical slot which renders the socket compressible, and a horizontal through hole having a tapered portion on one side of the vertical slot. A rod gripping cross-bar member, which is mounted through the through hole includes an axial split which permits the first end thereof to grip a rod, and then to be clamped onto the rod when the axial slot is narrowed. A nut is provided on the end of the cross-bar member which extend out from the through hole on the opposite end from the rod gripping mechanism.

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 a belleville washer. In a first embodiment there are two belleville washers which are oriented in opposite directions such that the narrow ends thereof are in contact with each other and the wider ends are in contact with the respective end plates. In a second embodiment there is a single belleville washer 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 is lockably mounted to the head such that the wider portion of the washer seats against the upper plate.

Abstract: A polyaxial orthopedic device for use with rod implant apparatus includes a screw having a curvate head, a cross bar mounting element having a socket into which the head of the screw is initially polyaxially nested. The cross bar mounting element further includes a vertical split which permits the socket to be expanded or compressed via the application of a corresponding force directed at the split. The cross bar mounting element further includes a pair of upwardly extending members which define a trough into which a cross bar element is positioned. The cross bar element includes features which permit the secure fixation of a rod thereto, as well as a selectively slideable element, such as a nut, which may be tightened to apply the compressive force necessary to compress the interior volume onto the head of the screw, thus locking the assembly in place.

Abstract: A rod, screw, and staple assembly for use in conjunction with anterior or lateral spinal rod implant apparatus includes a vertebral body screw which has a shaft which is insertable into a vertebral bone, a tapered neck, and a head portion which includes a rod receiving channel and an annular recess. The vertebral body staple includes a flat portion which has a hole through it. The hole has a slotted rim which is downwardly sloped so that it may permit the expansion of the hole when a force is applied to it. The screw is advanced into the hole in the staple until the tapered neck thereof snaps through the hole and the rim seats in the annular recess of the screw. This permits the screw and staple to rotate relative to one another, but not to translate axially relative to one another. The staple also includes several barbs which independently hold the staple to the bone surface to which it is to be affixed.

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.