According to some embodiments, systems and methods of ultrasonic detection of implantable medical device distraction are provided. The system includes a first elongate member and a second elongate member. The first elongate member has a first end that is configured to be attached to a first location on the skeletal system of a subject, a second end, and at least one landmark identifiable using ultrasound. The second elongate member has a first end that is movably coupled to the second end of the first elongate member, a second end configured to be attached to a second location on the skeletal system, and at least one landmark identifiable using ultrasound. Movement of the first elongate member in relation to the second elongate member causes a corresponding movement of the at least one first landmark in relation to the at least one second landmark which can be detected using ultrasound.

Some embodiments relate to a pedicle screw implant construct kit, comprising: at least one pedicle screw including a head; an embracing structure shaped and sized for embracing at least a portion of the screw head; an upper fastener for mounting onto the embracing structure, the upper fastener having a polygonal profile at least on a face of the upper fastener facing a direction opposite the screw.

A method for securing a longitudinal connection member assembly into multiple bone anchors by inserting the assembly into the bone anchors before or after the assembly is tensioned. The assembly includes a tensionable cord, an outer end blocker, and a set screw. The cord has a first end portion fixedly connected to a first structure, extends through a through-bore of a second structure, and has a second end portion that extends through a blocker through-bore of the outer end blocker. The outer end blocker has oppositely spaced lateral external planar surfaces and a threaded closed bore. The set screw is releasably engageable to the outer end blocker via the threaded closed bore. The method further includes tensioning the cord from the second end portion, holding the planar surfaces during tensioning of the cord within the blocker, and securing the tensioned cord to the outer end blocker by the set screw.

A coupling device for coupling a rod to a bone anchor includes a receiving part configured to receive a head of the bone anchor, the receiving part having a first end and a second end, a central axis that extends between the first and second ends, and two legs at the first end that define a recess extending in a longitudinal direction transverse to the central axis for receiving the rod, and a monolithic pressure member positionable in the receiving part, the pressure member including a rod support surface and an engagement portion to adjust the pressure member to exert pressure on the head. The engagement portion is positioned farther radially from the central axis in the longitudinal direction than a first portion of the rod support surface, and extends closer axially to the first end of the receiving part than the entire first portion of the rod support surface.

A dynamic longitudinal connecting member assembly includes an anchor member having an integral or otherwise fixed elongate core of circular or non-circular cross-section. The core is pre-tensioned and extends through at least one elastic spacer and at least one outer sleeve. The anchor member and the outer sleeve each attach to at least one bone anchor. In operation, the core is held in tension by the spacer.

A dynamic longitudinal connecting member assembly includes an anchor member having an integral or otherwise fixed elongate core of circular or non-circular cross-section. The core is pre-tensioned and extends through at least one elastic spacer and at least one outer sleeve. The anchor member and the outer sleeve each attach to at least one bone anchor. In operation, the core is held in tension by the spacer.

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. In a first embodiment, the transition portion includes a rigid length or rod having apertures therein for tying or otherwise attaching the rigid length to a second rigid length or to a flexible cord. Slender ties or cords extend through a plurality of apertures in the rigid lengths or are threaded, tied or plaited to the larger flexible cord or cable. In a second embodiment, a transition portion includes slender ties of a cord that are imbedded in a molded plastic of a more rigid member. The outer sleeve may include compression grooves. 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.

An artificial functional spinal unit including an expandable intervertebral implant that can be inserted via a posterior surgical approach and used with one or more facet replacement devices to provide an anatomically correct range of motion is described. Lordotic and non-lordotic expandable, articulating implants and cages are described, along with embodiments of facet replacement devices and instruments for insertion. Methods of insertion are also described.

Systems, devices, and associated methods for correcting spinal column deformities that help minimize a number of attachment anchors utilized for correction, facilitate use of straight or contoured rods, and/or help promote a more natural, physiologic motion of the spinal column.

A pivotal bone anchor assembly includes a receiver having upright arms defining a receiver channel for receiving an elongate rod, and an axial bore extending downward from the receiver channel to a bottom opening. The upright arms include break-off extensions, outer horizontally extending curvate tool engagement grooves, and side apertures extending inwardly from outer surfaces of the upright arms to deformable crimp wall portions adjacent the axial bore. The assembly also includes a shank having an anchor portion and an integral upper portion that is positionable in the axial bore of the receiver with the shank extending downward through the bottom opening. The assembly further includes an insert with an insert channel positionable within the axial bore and having opposing depressions formed into side surfaces that are configured to cooperate with the crimp wall portions of the receiver to maintain the insert channel in alignment with the receiver channel.