An intervertebral implant may include a shaft having a proximal end, a distal end, a longitudinal axis, a minor diameter, and a helical thread disposed about the shaft along the longitudinal axis between the proximal end and the distal end of the shaft. The helical thread may include a major diameter and a concave undercut surface angled towards one of the proximal end and the distal end of the shaft. The intervertebral implant may be implanted within an intervertebral space between a superior vertebral body and an inferior vertebral body. A ratio of the major diameter to the minor diameter may be less than 1.50. The concave undercut surface may engage the superior vertebral body and the inferior vertebral body and may be shaped to resist at least one force transmitted between the superior vertebral body and the inferior vertebral body to stabilize the intervertebral space.

An interbody implant system for use in the spine includes a base comprising two or more bone contacting surfaces, at least one recess in at least one of the two or more bone contacting surfaces, the recess configured for containing a tooth, a deployable tooth to provide fixation between the base and the anatomy of a subject, a break-away bridge between the tooth and the base for providing a first relative position between the tooth and the base, and a locking mechanism for providing a second relative position between the tooth and the base.

A bone disunion fastener may include a fastener shaft, a helical thread, and a bone staple. The helical thread may include a concave undercut surface oriented towards one end of the fastener shaft. The bone staple may include a first bone-engaging feature, a second bone-engaging feature, and a middle portion with an opening. The bone disunion fastener may be implanted along a disunion between a first bone portion and a second bone portion. The concave undercut surface may be shaped to resist at least one force transmitted between the first bone portion and the second bone portion to stabilize the disunion. The first bone-engaging feature may engage the first bone portion and the second bone-engaging feature may engage the second bone portion to couple the bone staple to the bone portions and resist at least one force transmitted between the bone portions to stabilize the disunion.

A system for stabilizing a cervical spine segment includes a pair of uncinate joint stabilizers for stabilizing a respective pair of uncinate joints. Each uncinate joint stabilizer is elongated along a lengthwise dimension and is configured for placement in the respective uncinate joint with the lengthwise dimension substantially oriented along an anterior-to-posterior direction of the cervical spine segment. Each uncinate joint stabilizer has height configured to define spacing of the respective uncinate joint. Each uncinate joint stabilizer includes a generally cylindrical portion with cylinder axis in the lengthwise dimension. The generally cylindrical portion has threads for threading the uncinate joint stabilizer into the respective uncinate joint along the anterior-to-posterior direction. The threads are interrupted by one or more fenestrations configured to accommodate bone graft material, bone growth, and/or tissue displaced from the respective uncinate joint by the uncinate joint stabilizer.

A vertebral body system and method having a polyaxial fastener receiving member, adjustable width plates and a pedicle screw having a pedicle threaded portion and a threaded portion for fastening to the vertebral body.

A spinal implant system is provided for bridging an intervertebral space between vertebral bodies bordering the intervertebral space. The spinal implant system includes at least one adjustable end cap and a spinal implant. The end cap can be used with additional end caps and/or the spinal implant. Multiple end caps can be stacked on top of one another, and one end cap can be attached to a first end of the spinal implant, and another end cap can be attached to a second end of the spinal implant. Thus, one or more of the end caps can be attached to either end of the spinal implant.

An interbody fusion cage having upper and lower canals for receiving the heads of bone screws that have been pre-installed in opposing vertebral body endplates. The proximal wall of the cage preferably has a vertical slot that communicates with each canal and is adapted to allow access by a screwdriver and tightening of the screws.

A method of treating a spine includes implanting a spinal implant within a patient. The spinal implant includes a first member having a first wall defining an axial passageway and a first opening, the first opening being in communication with the axial passageway. A second member includes a second wall defining an axial channel having the first member disposed therein, the second wall defining a second opening in communication with the axial channel. Bone graft is injected through the first opening and into the axial passageway and through the second opening and into the axial channel after the spinal implant is implanted within the patient.

An expandable vertebral body device, system, instrument, and methods of assembly and using the device, system, and instrument are disclosed. The vertebral body device includes a body with a first end and a second end, a first rotating member rotatably coupled to the first end, a second rotating member rotatably coupled to the second end, a first extension member moveably coupled to the first end, and a second extension member moveably coupled to the second end. The expandable cage system comprises a vertebral body device and an insertion instrument. Methods for assembling and using the vertebral body device and instrument are also disclosed.

An interbody spacer for a spine includes a housing having a plurality of clearance holes configured to engage bone of the spine. A contact plate including a plurality of apertures is positioned a distance away from the housing configured to engage bone of the spine. A plurality of rivets adjoin the housing and the contact plate. A plurality of springs are included with each spring configured to encircle a respective rivet and translate the distance between the housing and contact plate from a minimum distance to a maximum distance.