A method of assembling a pivotal bone anchor assembly includes positioning a retaining structure into a central bore of a receiver having a planar seating surface above a lower opening, the retaining structure being operably slidably coupled with the planar seating surface and having a central opening, the receiver including upright arms defining an open channel configured to receive a rod and exterior surfaces comprising opposite cylindrical upper side surfaces defining a first width and opposite lower side surfaces below the upper side surfaces defining a second width. The method also includes positioning a partially spherical head of a shank into the central opening of the retaining structure, with the retaining structure being slidably movable along the planar seating surface of the receiver to provide for increased articulated movement between the shank and the receiver in at least one direction relative to a vertical centerline axis of the receiver prior to locking the assembly with a closure.

A dynamic fixation medical implant having at least two bone anchors includes a longitudinal connecting member assembly having at least one transition portion and cooperating outer sleeve, both the transition portion and sleeve being disposed between the two bone anchors. The transition portion includes a rigid length or rod having apertures therein and a molded plastic length that extends through the apertures, thus attaching the plastic length to the rigid length. The sleeve surrounds the transition portion and extends between the pair of bone anchors, the sleeve being compressible in a longitudinal direction between the bone anchors.

In some embodiments, a spinal stabilization system may be formed in a patient using quick-connect sleeve assemblies. Each quick-connect sleeve assembly can be coupled to a bone fastener assembly in a fast and intuitive way. In one embodiment, a quick-connect sleeve assembly has a detachable member and a movable member. Both members engage a collar of the bone fastener assembly. In one embodiment, the engagement can be locked via one or more locking features to facilitate screwing a bone fastener of the bone fastener assembly onto a vertebral body in a minimally invasive surgical procedure. Each quick-connect sleeve assembly has a low profile and is particularly shaped for minimally invasive entry.

Growth directed correction of a spine via apical vertebral control includes securing a correction system to a first vertebra and a second vertebra of the spine, the correction system defining a correction axis extending between the first and second vertebra and securing the correction system to a third vertebra intermediate the first and second vertebra, the correction system securing the third vertebra at a fixed distance from the correction axis. The correction system is secured to the first and second vertebra such that the first and second vertebra are able to grow away from one another in a direction substantially parallel to the correction axis.

A posterior vertebral plating system comprising a plate and a plurality of attachment members. The plate has a plurality of holes extending through the plate from an upper surface to a lower surface, and the plate is configured to extend along the posterior side of at least two vertebrae adjacent at least one boney structure of each of the vertebrae. The holes are spaced in such a way that a first plurality of holes is positionable over a boney structure of a first vertebra to define a plurality of fixation points to the first vertebra and a second plurality of holes is positionable over boney structure of a second vertebra to define a plurality of fixation points to the second vertebra. The attachment members are insertable through the holes of the plate and into the boney structure of a corresponding vertebra to fix the plate to the vertebra.

A polyaxial bone screw assembly includes a threaded shank body having an integral upper portion receivable in an integral receiver, the receiver having an upper channel for receiving a longitudinal connecting member and a lower cavity cooperating with a lower opening. A down-loadable compression insert, a down-loadable friction fit split retaining ring having inner and outer tangs and an up-loadable shank upper portion cooperate to provide for pop- or snap-on assembly of the shank with the receiver either prior to or after implantation of the shank into a vertebra. The shank and receiver once assembled cannot be disassembled.

Various methods and devices are provided for tensioning a tether. In one embodiment, a tether tensioning device is provided and includes an elongate shaft adapted to be positioned adjacent to a bone anchor implanted in bone, and a tensioning mechanism pivotally associated with the elongate shaft and adapted to couple to a tether seated across the bone anchor and to pivot relative to the elongate shaft to apply a tensioning force to the tether.

A bone anchoring element comprising a shaft (2) for anchoring in a bone, with a plurality of barb elements (7) arranged in at least one helical line around the shaft axis (M) is described, wherein said barb elements are elastically movable relative to the shaft. The bone anchoring element (1) is easy to press into a core hole bore in a bone. The barb elements (7) act in a similar manner as do the threads on a conventional bone screw and thus provide for depth positioning. Moreover, the barb elements at the same time secure the bone anchoring element and prevent it from sliding-out.

The present application is directed to various spinal stabilization systems. The systems can include one or more guiding elements attached to screw members to assist in guiding rod implants and tools to desired locations within a patient. The guiding elements can include a plurality of wires, blades, or tabs. The guiding elements can be capable of criss-crossing or intersecting at or near an incision, such that only a single incision may be needed to perform a surgery. The guiding elements can also include telescoping features that allow the height of the guiding elements to be adjusted in use, thereby allowing multiple telescoping guiding elements to be used with the same incision.

A posterior spinal fusion system may include a plurality of cannulas that mate with cages polyaxially coupled to pedicle screws. The cannulas maintain access to the pedicle screws to facilitate percutaneous insertion of a fusion rod into engagement with the cages. Each cannula has a pair of blades that may be held together by an abutment member that at least partially encircles the blades. Each abutment member abuts the skin to define a variable subcutaneous length of the corresponding cannula. Each abutment members is also lockably removable from the corresponding blades to enable the blades to pivot with respect to the connecting element to a position in which they can be withdrawn from the connecting element. The blades of each cannula are spaced apart to provide first and second slots of each cannula, through which the fusion rod can be percutaneously inserted.