A pivotal bone anchor assembly includes a receiver with a cavity and a rod-receiving channel having opposed interior surfaces with a downwardly-facing surface located below a discontinuous closure mating structure, and a shank having an upper capture portion uploadable into the receiver cavity through a bottom opening. The pivotal bone anchor assembly also includes a retainer disposed within the receiver cavity for capturing the shank upper capture portion therein, and a compression insert disposed within the receiver channel having an upper rod-engaging surface, a lower retainer-engaging surface, and an overlapping arrangement with the receiver channel downwardly-facing surface to inhibit upward movement of the compression insert within the receiver after the retainer has captured the shank upper capture in the receiver cavity, with the compression insert remaining spaced apart from the shank upper capture portion when the shank is pivoted with respect to the receiver.

A method of assembling a pivotal bone screw assembly includes positioning a capture portion of a shank and a ring shaped structure into a central bore of a receiver, the central bore having an upper retaining recess and a support surface adjacent a lower opening and the capture portion having a partial spherical lower surface to provide for pivotal motion of the shank relative to the receiver. The method also includes top loading an insert into the central bore, the insert having an upward-facing insert channel for engaging the rod, laterally-outward-projecting flanges at an upper end, and a bottom surface for applying downward compressive force to the ring shaped structure. The method further includes downwardly displacing the insert within the central bore as the flanges resiliently deflect inwards and then spring back outwards to snap into the upper retaining recess to prevent the insert from moving back up within the receiver.

An implant for the stabilization of bones or vertebrae is provided, the implant being a solid body including a longitudinal axis that defines a longitudinal direction and including a flexible section that has a surface and has a length in the longitudinal direction, the flexible section including at least one cavity located near the surface and having a width in the longitudinal direction that is smaller than the length of the flexible section, the at least one cavity being connected to the surface through at least one slit, and a width of the slit in the longitudinal direction being smaller than the width of the cavity.

An orthopaedic stabilisation device is described. The orthopaedic stabilisation device comprises a stabilisation member and at least two legs coupled to the stabilisation member. Each leg is arranged for positioning in a respective bore hole in bone, and for receiving an element within the leg such that the element can facilitate fastening the leg within the bore hole in bone. The stabilisation member may be arranged such that a length of the stabilisation member is alterable by a predefined amount, the predefined amount being adjustable.

The present invention relates to a bio-flexible spinal fixation apparatus capable of realizing motions similar to general body mechanical motions during flexion and extension motions after spinal fixation surgery by configuring a center of a coil part of a rod to have a eccentricity at a certain distance from a center line of a straight part and a specific inclination, and conveniently performing an operation of setting a fixing position of the rod during spinal fixation surgery by machining the straight part section of the rod into a flat surface. The present invention includes a screw pike that includes a head part and a screw; a rod that has a straight part and a coil part wound to be inclined by a predetermined angle with an eccentricity from a center of the straight part; and a set screw.

A polyaxial bone screw assembly includes a threaded shank body having an upper portion with a capture structure thereon, a retaining and articulating structure, a compression structure and a receiver for holding the capture structure, retaining and articulating structure, compression structure and a rod. The receiver includes arms that define a channel for receiving the rod. The arms have inner surfaces with a discontinuous flange form thereon for mating with a cooperating continuous flange form of a closure structure for capturing the rod within the receiver. The shank capture structure and the retaining and articulating structure are threadably attached and secured to one another with a buttress stop. In operation, the compression structure is disposed within the receiver between the shank upper portion and a rod but presses only upon the retaining and articulating structure. The retaining and articulating structure has an external substantially spherical surface that mates with an internal surface of the receiver, providing a ball joint, enabling the receiver to be disposed at numerous angles relative to the shank body. The shank upper portion includes a tool engagement formation for driving the shank body into bone.

A spinal distraction system including a bearing connector fastened to a fixated rod and a sliding rod, wherein the sliding rod includes a spring and a stop ring is disclosed. A method of distracting vertebrae is also disclosed.

A dynamic fixation medical implant includes a longitudinal connecting member assembly having an elongate coil-like outer member and an inner cylindrical core attached to the outer member at only one end thereof. Some assemblies include a second longitudinal connecting member in the form of a rod that is fixed to the inner core and extends outwardly from the assembly. Certain assemblies include a threaded core or threaded inserts that cooperate with a helical slit of the coil-like outer member. Two or more cooperating bone screw assemblies attach to the connecting member assembly. The bone screw assemblies may include upper and lower compression members for affixing to and cradling the coil-like outer member only, allowing relative movement between the outer member and the inner cylindrical core. Press fit or snap-on features attach one end of the coil-like outer member to one end of the inner cylindrical core.

A functionally dynamic stabilization unit and system for treatment of spinal instability are provided. Each unit, and collectively, the system, is configured to control flexion, extension and translation of the affected unstable vertebral area, thereby stabilizing the vertebral segments by restoring normal function. This is achieved by providing a unit and system that allow for lateral bending, axial compression, rotation, anterior segmental height adjustment, and posterior segmental height adjustment. The unit and system provide sufficient segmental stiffness, while also limiting, or controlling, the range of motion (i.e., sufficient stiffness in the neutral or active zone, while limiting or preventing motion outside of the active zone) to stabilize the vertebral segments. In use, the system mimics the natural movement of the normal spine. Furthermore, the system includes a rigid, fusion-promoting coupler configured for use in an adjacent level, or as a substitute for the functionally dynamic unit. The modularity of the system allows adjustment over time and easier revision surgery, and is configured for minimally-invasive, delivery or implantation.

An implant for the stabilization of bones or vertebrae is provided, the implant being a solid body including a longitudinal axis that defines a longitudinal direction and including a flexible section that has a surface and has a length in the longitudinal direction, the flexible section including at least one cavity located near the surface and having a width in the longitudinal direction that is smaller than the length of the flexible section, the at least one cavity being connected to the surface through at least one slit, and a width of the slit in the longitudinal direction being smaller than the width of the cavity.