Abstract: A tool for installing an object, such as an artificial disk prosthesis, between adjacent vertebrae includes a pair of opposed levers separated by a fulcrum. Blade tips are disposed at the distal end of the levers. A pusher block is disposed distally of the fulcrum, and upon actuation by forward movement of a pusher rod, the pusher block moves the artificial disk prosthesis distally. The blade tips may be inserted between adjacent vertebral bodies as the disk moves forward thus causing the vertebral bodies to be separated until the disk is disposed therebetween. In one embodiment, the length of the blade tips may be selectively adjusted.

Abstract: A halo crown has depending posterior legs adjustable in multiple dimensions for conveniently adjusting the halo crown to a patient's skull. Each leg slides along a single axis yet provides adjustments in three dimensions due to a portion thereof extending downwardly, inwardly and rearwardly and the orientation of the axis.

Abstract: A surgical retractor system comprises a support frame and at least one retractor blade. The support frame has a generally horizontally oriented support member comprising a plurality of holes. The surgical retractor has at least one retractor blade which is mateable at a selected position on the support frame. At least one retractor blade of the surgical retractor system has an open access window which provides greater visual and physical access to the surgical field.

Abstract: An improved prosthetic implant for forming a rigid structure between adjoining vertebrae in a spinal column. The prosthetic implant includes a cage having a top, bottom, front end, back end, first side and second side walls. The first side wall has an arcuate surface. The top and bottom wall include one or more ridges to engage a surface of an adjacent vertebrae. The top and bottom wall also include an opening to receive packing material such as medicine, human tissue and the like. The top and bottom walls also incline simultaneously in two directions.

Abstract: A spinal fixation assembly includes a fusion cage to which a plate is mated. The plate is configured to receive, retain and orient bone screws.

Abstract: A skull pin has a ceramic insulating portion between a titanium driving portion and a titanium tip portion. The driving portion of the skull pin terminates in a sleeve, and the ceramic insulator with a solid cylindrical shape is received such as with a press fit in the sleeve. The preferred ceramic material is zirconia. The tip portion has an opposing outer sleeve which receives the distal end of the ceramic insulator such as with a press fit. The ceramic insulator is believed to reduce or eliminate a burning sensation felt by patients during Magnetic Resonance Imaging (MRI), which may be caused by transmission of high (radio) frequency electrical signals through the prior art skull pins.

Abstract: A spinal disc prosthesis to replace a damaged spinal disc in a spinal column (16) of a human, includes a body (10) having an upper surface (52) engageable with the upper vertebra (12) and a lower surface (152) engageable with the lower vertebra (14). The body (10) includes a crescent-shaped projection (62, 162) extending from one of the upper and lower surfaces (52, 152) of the body for receipt in a cavity in the adjacent vertebra (12, 14).

Abstract: A bone plate apparatus of the present invention includes a plate having a slot extending between the superior and inferior surfaces of the plate, and a rim extending about the slot which includes an interrupted surface, a fastener including a shaft formed for extension into the bone, a collar coupled to the shaft having an interrupted surface which mates with the interrupted surface of the rim of the slot, and a head coupled to the collar for movement in the slot, and a nut forred to cooperate with the head of the fastener to couple the interrupted surfaces of the fastener and the rim together, thereby locking the head in a fixed position within the slot.

Abstract: A kit is for removing a spacer having a surface and ends from a spine. The kit includes an osteotome, a threaded extractor, and a trephine, each for releasing spacer from spine. Osteotome includes a cutting portion having a surface formed to engage surface of spacer and a tip formed to cut bone surrounding surface of spacer. Extractor includes a side wall having threads formed to cut one of the ends of spacer and pull spacer away from spine when side wall rotates relative to spacer. Trephine includes a blade having a sleeve defining a passageway and including an edge formed to cut material surrounding surface of spacer.

Abstract: An apparatus for retaining first and second vertebrae of a spinal column in a desired spatial relationship includes a longitudinal member positionable along the spinal column. A member, such as a plate, connectable with the first vertebra has first and second fastener openings and a portion engageable with the longitudinal member. A first fastener extendable through the first fastener opening in the member has a first end portion for attachment to the first vertebra and has a longitudinal axis. A second fastener extendable through the second fastener opening in the member has a first end portion for attachment to the first vertebra and has a longitudinal axis. The longitudinal axes of the first and second fasteners converge at an acute angle as viewed in a sagittal plane when the first and second fasteners connect the member with the first vertebra. The member connectable with the first vertebra has a body portion and has a lip portion projecting from the body portion of the member.

Abstract: A spinal disc prosthesis to replace a damaged spinal disc in a spinal column of a human includes an upper rigid plate having an outer perimeter and a lower rigid plate having an outer perimeter. A body of elastomeric material located between and bonded to the upper and lower rigid plates includes a main portion and a peripheral portion extending around the main portion. The upper and lower plates each have a curved convex plate surface extending around the respective outer perimeters and facing the peripheral portion of the body of elastomeric material. The peripheral portion of the body of elastomeric material has a first part which is bonded to the curved convex plate surfaces of the upper and lower plates and extends toward the main portion. The first part of the peripheral portion increases in thickness as the first part extends from the curved convex plate surfaces toward the main portion.

Abstract: A spacer-insertion instrument for delivering a spacer to a spine is disclosed. The instrument includes a handle portion and a guide coupled to the handle portion. The instrument further includes a shaft coupled to the handle portion and extending along the guide. The instrument further includes a tip including an attachment end portion coupled to the shaft and opposing fingers movable relative to one another and adapted to grasp the spacer when the shaft is moved to actuate the fingers. The handle portion includes a grip and a trigger coupled to the grip and to the shaft and movement of the trigger toward the grip causes the fingers to move toward one another. A method for delivering a vertebral body spacer to a disc space formed in a spine between adjacent vertebral bodies is also disclosed.

Abstract: Surgical prosthetic modular devices used singularly or stacked together are provided for use to replace excised vertebral tissue. The devices are rigid plugs, dimensionally similar to normal vertebral bodies, and have ridged faces to engage adjacent vertebral bodies or to interdigitate when stacked. Ridges extend in both the medial/lateral and anterior/posterior directions to prevent slipping in the anterior/posterior and medial/lateral directions respectively. A locking screw may be used to secure a stack to form a singular rigid prosthetic device. The devices are also provided with a plurality of threaded openings. In the method of this invention, a device is used to replace excised vertebral tissue, threaded bolts are inserted into the threaded openings, and other spine stabilization devices are attached to the bolts. In corporectomies, the device can be bolted to a plate, which in turn is fixed to adjacent vertebrae. In spondylectomies, the device can be fixed to a series of posteriorly placed rods.

Abstract: A bone screw annd assembly are described wherein the bone screw has a dual lead thread that is provided as an offset thread. The bone screw has two leads starting less than 180.degree. apart. Because the leads start less than 180.degree. apart, the leads appear to spiral together along the shaft of the bone screw, creating a large groove and a small groove. The offset dual lead thread of the present invention provides enhanced pullout resistance by overcoming machining limitations to produce a bone screw with increased thread depth while maintaining or decreasing thread pitch. The bone screw may also be provided together with a bone plate to comprise a bone fixation assembly.

Abstract: A spacer assembly is provided for use in spinal surgeries. The spacer assembly includes a spacer having opposite ends and a side wall extending between the opposite ends and at least one end cap coupled to at least one of the opposite ends of the spacer. Each end cap includes an inner end facing the spacer, an outer end, and a side wall extending between the inner and outer ends. The side wall of each end cap is formed for engagement with the side wall of the spacer to provide a mechanical connection between the end cap and the spacer.

Abstract: A method and apparatus is provided to retain elements of the spine and/or pelvis in a desired spatial relationship. A plurality of fasteners are connected with a plurality of the elements. A longitudinal member is connected with the fasteners by a plurality of connector members. The longitudinal member and fasteners are movable relative to each other to adjust the distance between the longitudinal member and fasteners to thereby obtain the desired spatial relationship between the longitudinal member and elements to which the fasteners are connected. Once the longitudinal member and fasteners have been positioned in the desired spatial relationship, clamps are engaged to hold the longitudinal member, fasteners and connector members against relative movement. To provide for the adjustability of the longitudinal member relative to the fasteners, oblong openings are formed in the connector members.

Abstract: A locking plate apparatus for engagement with a bone is provided in accordance with the present invention. Locking plate apparatus includes a plate that has a body portion and an internal wall defining a plate hole through body portion and a bushing with a passageway therethrough. Bushing is sized for polyaxial rotation within plate hole. Locking plate apparatus also includes an attachment component that has a leading portion sized for extension through passageway and into bone and an opposite trailing portion. Trailing portion presses bushing against internal wall of plate to forrn a friction lock between bushing and plate in a selected polyaxial position.