The present disclosure includes bone screws and assemblies thereof for surgical procedures of the spine including but not limited to posterior spinal fixation procedures.

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blades to enable the blades to pivot with respect to the connecting element to a position in which they can be withdrawn from the connecting element.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.

A polyaxial bone screw assembly includes a threaded shank body having an upper portion, a receiver member or head, a retaining and articulating structure, and a pressure insert disposed between the shank upper portion and a rod. The receiver has a U-shaped cradle defining a channel for receiving a spinal fixation rod and a receiver cavity. The retaining and articulating structure attaches to the shank and rotates with the shank in the cavity during positioning. The pressure insert presses upon the shank upper portion and not the retaining and articulating structure.

The present invention relates to stable fixation of spine segments, allowing for fusion in, e.g., skeletally mature patients. More particularly, the invention relates to a bone fixation device that can be affixed to vertebrae of a spine to provide reduction (or enlargement) capabilities and allow for fixation in the treatment of various conditions, including, e.g., spondyloslisthesis, degenerative disc disease, fracture, dislocation, spinal tumor, failed previous fusion, and the like, in the spine. The invention also relates to a method for delivering and implanting the bone fixation device.

A bone screw assembly includes an anchor portion and a head portion, such as a rod-receiving portion, movably mounted to the anchor portion to allow for controlled angulation between the anchor portion and the head portion. The anchor portion is pivotable in one or more selected directions about an axis relative to the head portion. A restriction member, which may be a rod seat, prevents the anchor portion from pivoting in one or more different directions about another axis relative to the head portion and/or a spinal fixation element received in the head portion. The restriction member may be inserted in the head portion to control direction that the anchor portion pivots relative to the head portion. The restriction member may also serve as a compression member and/or rod seat for seating a spinal rod coupled to the bone screw assembly.

A device may include an outer sleeve with a hollow interior, and an inner sleeve with a hollow interior to couple axially and slidingly. The outer sleeve may include an outer central body, an outer proximal end part and an outer distal end part integrally connected to one another, and an outer channel extending along the entire outer proximal end part and along a substantial portion of the outer central body. The inner sleeve may include an inner central body, an inner proximal end part and an inner distal end part integrally connected to one another, and an inner channel extending along the entire inner proximal end part and along a substantial part of the inner central body. The inner sleeve may include, in the inner proximal end of the inner sleeve, a lateral engagement element, and an axial engagement element for releasably engaging a surgical screw.

A spinal stabilization system and method are provided for treating a patient's spinal column, for maintaining preselected spacing and movement between adjacent vertebrae in a spinal column, and for providing overall stability thereto. The system includes an interlaminar member positioned in the space intermediate a first vertebra and the vertebrae positioned immediately below and adjacent to the first vertebra. The interlaminar member is operatively connected to an adjustable support structure and cooperates therewith to maintain the preselected spacing between adjacent vertebrae and to provide overall stability to the spinal column.

A bone fastener system can comprise a fastener and a first sizing component. The fastener can comprise a shaft that provides an anchoring footprint. The first sizing component can be configured to be connected to the shaft and can include a first anchoring feature, or circumferential bone engaging feature, to increase a size of the anchoring footprint. The first anchoring feature can comprise a sleeve that radially expands a diameter of the threaded shaft. The first anchoring feature can comprise axially extending teeth. The system can further comprise a second sizing component including a second anchoring feature to increase the size of the anchoring footprint, the second anchoring feature being different from the first anchoring feature. The second anchoring feature can expand the diameter of the threaded shaft a greater amount than the first anchoring feature. The second anchoring feature can have a length greater than the first anchoring feature.

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.

A load sensing assembly for a spinal implant includes a set screw having a central opening that extends from a first end of the set screw toward a second end of the set screw. The second end of the set screw is configured to engage with an anchoring member. The load sensing assembly includes an antenna, an integrated circuit in communication with the antenna, where the integrated circuit is positioned within the central opening of the set screw, and a strain gauge in connection with the integrated circuit. The strain gauge is located within the central opening of the set screw in proximity to the second end of the set screw.