A pivotal bone anchor assembly includes a shank having a shank head with a partial spherical shape at a proximal end and an anchor portion opposite the shank head for fixation to the bone of a patient. The assembly also includes a receiver having an upper portion defining a channel for receiving an elongate rod and a base defining a cavity in communication with the channel and with a bottom surface of the receiver through a distal opening. The assembly further includes a retainer positionable into non-rotatable and non-pivotal engagement with an inner surface of the cavity prior to the shank head being received within the cavity, with the retainer having a central opening configured to receive and capture the shank head within the cavity while allowing for pivotal motion between the shank and the receiver in at least one plane, and with a lower portion of the retainer extending below the bottom surface of the receiver.

A receiver assembly for capturing an elongate rod in a receiver of a bone anchor includes the receiver, a first threaded closure, and a second threaded closure. The receiver includes an upper portion that defines a first channel, interior surfaces that have helically wound thread, and a lower pressure insert that can be positioned within the first channel and has upright arms. Each of the first threaded closure and the second threaded closure have a cylindrical body with an external surface having continuous helically wound thread that can rotatably mate with the helically wound receiver thread. The first threaded closure and the second threaded closure are interchangeable for different locking configurations in the receiver assembly. The first threaded closure has a downward protrusion that can compressively engage the elongate rod. The second threaded closure has a bottom surface that can compressively engage the upright arms of the lower pressure insert.

A vertebral column correction system for correcting a spinal deformity without fusing the joint segments is disclosed. The vertebral column correction system may have first and second vertebral anchors secured to first and second vertebrae. The vertebral column correction system may further comprise one or more intermediate vertebral anchors secured to vertebrae between the first and second vertebrae. A connection member may be disposed within a head portion of the vertebral anchors. At least a portion of the connection member may be a flexible member, such as a flexible cord, configured for tensioning between at least two vertebral anchors for providing a desired amount of tension to apply a correctional force to the spinal column. A spring member, or other tensioning member, may maintain the tension of the connection member.

A soft dynamic stabilization assembly includes a core, typically in the form of a tensioned cord, at least one pair of bone anchors, a spacer surrounding the core located between the bone anchors, typically, at least one elastic bumper and at least one fixing or blocking member. The core is slidable with respect to at least one of the bone anchors and cooperating spacer.

A pivotal bone anchor assembly includes a shank having a head portion and an anchor portion for fixation to the bone of a patient, and a receiver comprising a base defining a lower portion of central bore and a pair of upright arms defining a channel for receiving an elongate rod. The assembly also includes a retaining structure with a central opening configured to capture and pivotally retain and support the head portion of the shank in the retaining structure, and which is slidably movable relative to the receiver so as to provide for increased articulated movement between the shank and the receiver prior to locking the assembly with the elongate rod and a closure. The assembly further includes an insert configured to engage the elongate rod and the head portion of the shank when in use, and to have an overlapping configuration with the retaining structure when the assembly is in the locked configuration.

A pivotal bone anchor assembly includes a shank having an anchor portion and a head with a partially spherical outer surface, a drive socket, an annular planar top surface surrounding the drive socket, and a frusto-conical surface between the planar top surface and the partially spherical outer surface. The assembly further includes a receiver having a base defining an axial bore and an upper portion defining a channel configured to receive a rod, and an insert positionable within the axial bore having an upper surface engageable with the rod, a lower surface for transferring a downwardly-directed force toward the head, and a central aperture for accessing the drive socket, with the rod extending across the central aperture when the fixation rod is engaged by the upper surface. After the head, the insert, and the rod are positioned in the receiver, the frusto-conical surface remains spaced apart from the rod to in all pivotal orientations of the shank relative to the receiver.

A dynamic fixation medical implant having at least two bone anchors includes a longitudinal connecting member assembly having rigid sleeves for attachment to the bone anchors, at least one spacer engaging the bone anchors and the sleeves, and in some embodiments, an end elastic bumper. A flexible cord is initially slidingly received within the rigid sleeves, the spacer and the bumper. The spacer may include an optional inelastic inner liner, with at least one of the sleeves having an extension slidingly receivable within the liner. Some sleeves include apertures for receiving a closure top portion for locking the cord against the sleeve, or alternatively receiving a closure top that does not extend into the aperture, the slip or grip option provided by the aperture in each sleeve resulting in an overall connector with variable segmental stiffness.

A tool set for implanting bone screws in a human spine, followed by the implantation of a rod into the bone screws includes end guide tools having flexible back wall flaps that receive opposite ends of the rod and intermediate guide tools that hold the rod in intermediate locations between the end guide tools. Both the end and intermediate guide tools include an attachment structure for operably connecting the guide tool to a bone screw. The attachment structure includes an undercut and/or recess so as to resist splaying and separation of the guide tool from an attached bone screw.

A modular pivotal bone anchor assembly includes a receiver having a central bore with a locking region adjacent a bottom opening, an expansion region above the locking region, an interference abutment surface above the expansion region, and a retaining groove above the interference abutment surface. The assembly also includes a bone screw having a head uploadable through the bottom opening, an insert positionable within the central bore with protruding engagement structures received within the retaining groove, an upper open ring positionable below the insert, and a lower open ring positionable below the upper open ring for capturing the head within the locking region, after which the upper open ring occupies the expansion region and the insert is downward deployed by tooling, with the engagement structures moving out of the retaining groove and into an overlapping arrangement with the interference abutment surface to inhibit upward movement.

The device for treating early onset scoliosis includes first and second tubes having first and second rods slidably disposed therein. The first tube is adapted for fixation to at least one middle vertebra of a patient's spine such that an open end thereof faces upward and a closed end thereof faces downward. The second tube is also adapted for fixation to at least one middle vertebra such that an open end thereof faces downward and a closed end thereof faces upward. A lower end of the first rod is positioned within the first tube and is resiliently biased. An upper end of the first rod is adapted for fixation to at least one upper vertebra. An upper end of the second rod is positioned within the second tube and is resiliently biased. A lower end of the second rod is adapted for fixation to at least one lower vertebra.