Abstract: A bone plate for use in anterior lumbar spinal fixation has interlocking components to prevent dislodgement of the plate due to anatomical forces. The exposed surface of the plate is smooth to prevent trauma to internal body tissue. The plate spans the intervertebral space with each end attached to an adjacent vertebrae by locking screws threadably engaged with tubular bone anchors. The bone anchors are threaded into the vertebrae and have a reduced diameter leading end which the locking screws expand to lock the anchor in the vertebrae and secure the end of the locking screw in the anchor. The plate has a countersunk cavity including portions overlapping the locking screws. A locking cap fits in the cavity to secure the other end of the locking screws from backing-out of the plate.

Abstract: A bone plate for use in anterior cervical spinal fixation has interlocking components to prevent dislodgement of the plate due to anatomical forces. The plate is formed in the shape of a block letter C and the exposed surface is smooth to prevent trauma to internal body tissue. The plate spans the intervertebral space with each end attached to an adjacent vertebrae by bone screws threadably engaged with the bone. The distal ends of the bone screws The plate has a screw lock in each end for preventing the locking screws from backing out.

Abstract: A bone plate for stabilizing adjacent vertebrae or ends of a bone has a span for extending across the discontinuity. The span has brackets for attaching to the bone. The brackets have countersunk bores terminating in apertures through which bone screws are placed in the bone. A lock screw aperture is located adjacent the countersunk bores with a portion of the sidewall forming a thin flexible tab in each bore. To prevent back-out of the bone screws, a lock screw is threaded into the lock screw aperture distorting the bore of the bone screw aperture.

Abstract: A spinal fusion device for implantation between adjacent vertebrae is formed in the approximate shape of a hollow cube. The device has an upper section and a lower section relatively movable with regard to each other. The sidewalls of the upper section and the lower section terminate in complementary inclined planes so that as the sections move away from each other the height of the device lessens and as the sections move toward each other the height of the device increases. A distractor is placed within the hollow body and contacts the upper and lower sections by a link which is used to adjust the height of the device.

Abstract: A drive system for a surgical fastener is composed of a drive tool with a drive tip that mates closely with the recess formed in the head of a threaded fastener. The surgical fastener has a head with a quadrilobe fitting therein which closely mates with the quardilobe tip of the tool. The cooperating drive surfaces align the fastener and tool coaxially and produce four point contact equidistant about the circumference of said fastener significantly reducing angular excursions of the fastener during placement in the bone.

Abstract: A polyaxial screw is used to secure orthopedic appliances to bone, particularly the spine. The polyaxial screw has a shaft including a helical screw thread for securing the screw to bone. One end of the shaft has a reverse tapered head tapering toward and away from the shaft from an enlarged median. A spherical shaped swivel, having an opening smaller than the median, is snapped over the head to rotatably engage the shaft. A connector with a dome shaped cavity on one end and bifurcated tabs on the other is connected with the swivel and tightened in place with a set screw and guide ring. An appliance is held between the bifurcated tabs. The tabs are frangible to reduce the profile above the appliance.

Abstract: A cross link system provides stability to spinal rods by maintaining a set distance between the rods. The cross link has a bar with connectors on each end formed with grooves that engage each of the spinal rods. Each of the connectors has a cam that can be manipulated to obstruct the groove and provide a friction fit between the spinal rod and the cross link. The cams have locking nuts that prevent disengagement of the cam and rod. The bar has two shafts interconnected by a bifurcated pin with upstanding ends, a piston is located between the upstanding ends and diverts shear forces along the longitudinal axis of the bar.