A polyaxial bone screw assembly includes a threaded shank body having an integral upper portion receivable in a receiver, the receiver having an upper channel for receiving a longitudinal connecting member and a lower cavity cooperating with a lower opening. The upper portion expands a retaining member in the receiver cavity to capture the shank upper portion in the receiver. In some embodiment either the retaining member or an insert provide for a friction fit of the shank upper portion in the receiver resulting in non-floppy placement of the shank with respect to the receiver. Some retainers and inserts have a lock-and-release feature. Final locking of the polyaxial mechanism is provided by frictional engagement between the shank upper portion and the retaining member. A pre-assembled receiver, retaining member and optional insert may be popped-on or snapped-on to the shank upper portion prior to or after implantation of the shank into a vertebra.

In one embodiment, a spinal stabilization apparatus includes a vertebral anchor having a head portion and a bone attachment portion. An elongate, flexible guide is removably coupled to the head portion of the vertebral anchor and has a channel extending longitudinally thereof and communicating with a slot in the head portion of the anchor. An elongate cord may be received within the channel to facilitate inserting and securing a spacer between pairs of anchors installed into adjacent vertebrae of a person's spine.

A medical implant assembly includes a polyaxial bone anchor having a shank, a receiver, a lower compression insert with planar surfaces for closely receiving an elongate connecting member with planar surfaces and a one-piece closure structure. The connecting member is made from a polymer. The closure structure engages both the connecting member and the insert with the engagement between the closure structure and the insert securely locking the polyaxial mechanism even if the connecting member exhibits creep.

The instant disclosure is directed to flexible electrospun fiber rods and methods of manufacturing such rods. A scaffold may comprise a flexible rod having a spiral cross-section, the flexible rod comprising electrospun polymer fibers. The electrospun polymer fibers may be substantially aligned or randomly oriented with respect to one another. The flexible rod may further comprise substantially uniformly distributed pores. The flexible rod may have a length and a diameter of a native mammalian tendon or ligament. A method of manufacturing such a scaffold may comprise forming a layer of polymer fibers on a mandrel by electrospinning, rolling the layer from a first end of the mandrel to a second end of the mandrel to form a toroid at the second end of the mandrel, and cutting the toroid off the mandrel to form a flexible rod having a spiral cross-section.

Implementations described herein include devices and systems for attenuation of increased spinal flexion loads post-fusion that include a transition member. The transition member may have a tension component coupleable to a fused vertebra of a plurality of fused vertebra of a fusion implant and to an adjacent unfused vertebra. The tension component may be tensionable to a selected value. The tension component may modulate a flexion range of motion of the adjacent unfused vertebra as a function of the selected value of tension of the tension component. The transition member may attenuate spinal flexion loads on adjacent unfused vertebra post-operatively.

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.

Implants, systems, and methods for securing a flexible band, thereby providing a desired correction to the spine. The implant may secure the flexible band to a spinal rod and/or a pedicle screw. The implant may include a first locking member configured to secure the spinal rod and a second locking member configured to secure the band. The band may be looped around bony anatomy and tensioned to achieve correction and provide fixation as an alternative and/or supplement to pedicle screws during spinal deformity surgery.

Methods for correction of spinal deformities using bone anchors having one or more features configured to actively draw in and/or compact vertebral bone into an inner chamber. In some implementations, a first bone anchor having an inner chamber may be advanced into a first vertebral body of a spinal column. One of more features of the inner chamber may, as the first bone anchor is rotatably or otherwise advanced, actively draw and compact vertebral bone into the inner chamber. A second bone anchor may be advanced into a second vertebral body of the spinal column, after which a tether may be coupled between the first and second bone anchors to apply a corrective force to at least a portion of the spinal column.

A system for installing a vertebral stabilization system. The system includes an installation tool including a handle portion and a shaft extending distally from the handle portion. The shaft includes a conduit and a staple mechanism. The system also includes a flexible implant member extending along the conduit configured to be advanced out from a distal end of the shaft, and a staple housed in the staple mechanism. The staple is configured to secure the flexible implant member to a vertebra. The handle portion is configured to selectively advance the flexible implant member from the shaft and to selectively actuate the staple mechanism.

A 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, 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, the spacer and the bumper. The bumper is compressed. Bone screws of the assembly include closure structures that lock against the bone screw independent of any fixing or sliding of the core with respect to the bone screw.