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.

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: The present invention describes a system comprised of a wedge, distractor channel, and a retractor. The wedge and distractor channel are combined in a nesting relationship and an impactor handle is then attached to the wedge/distractor channel combination to facilitate intervertebral positioning. Subsequent to insertion, the wedge is slidably disengaged while leaving the distractor channel in place, thereby forming an access port which provides an enhanced field of view of the interior spinal anatomy. A retractor is positioned in the incision allowing unobstructed view from outside the body to the access port and facilitates performance of such surgical procedures as discectomy, implant sizing and insertion, spinal fusion, and the like.