Abstract: In a rod fixation system of the type used to treat various spinal conditions, the same fastener is used to lock both a polyaxial screw and a rod in position. A spinal correction device according to the invention, adapted for use with a rod and a polyaxial screw having a ball-shaped head and a threaded end, comprises a head-body and a cap. The head-body includes a lower internal cavity to receive the ball-shaped head of the screw, an upper bore to receive a fixation rod therethrough, and an upper end configured to receive the cap. The head-body and the cap are configured such that a first rotation of the cap locks the polyaxial screw in position, and a second rotation of the cap locks the rod in position. In the preferred embodiment, the head-body includes one or more gaps to facilitate flexion of the head-body as a rotational torque is placed on the cap. The gap or gaps may be horizontal, vertical or other angles relative to the axis of the entrapped rod.

Abstract: The present disclosure provides systems and methods for retaining a plate, such as a cervical plate, to a substrate, such as bone, through a locking screw with upper asynchronous threads and lower cancellous threads. The present invention utilizes the locking screw with cancellous-type threads to draw the screw into the substrate. The screw is operable to retain a plate to the substrate and is configured to gall and lock to the plate through the upper threads which are out-of-phase with corresponding threads on the plate thereby preventing reverse threading or backing out of the screw.

Abstract: The present disclosure provides a micro-flail assembly and associated method of use for the preparation of a nucleus/vertebral end cap of a spine. The micro-flail assembly is utilized in the formation of a nucleus/vertebral end cap between adjacent vertebrae while simultaneously protecting an adjacent annulus with a protective sheath. The protective sheath also acts as a guide while the micro-flail assembly is pivoted to form the end cap. Advantageously, the present invention can be utilized with a variety of surgical procedures including minimally invasive surgery. The formation of the end cap can be done in preparation of providing an insert device (e.g., bone graft, cage, artificial disc, or the like).