A compression fastener may include a shaft and a helical thread disposed about the shaft. The shaft may include a proximal end, a distal end, a proximal shaft portion, and a distal shaft portion. The helical thread may include at least one concave undercut surface and a plurality of pitches that may include at least one first pitch along the proximal shaft portion and at least one second pitch along the distal shaft portion. The at least one concave undercut surface may be angled towards one of the proximal end and the distal end of the shaft, and the at least one first pitch and the at least one second pitch may not be equal to each other.

A bone implant may include a shaft having a proximal end, a distal end, a longitudinal axis, a proximal shaft portion, and a distal shaft portion. The proximal shaft portion may include a first minor diameter, and a first helical thread disposed about the proximal shaft portion defining a first major diameter. The first helical thread may include a first concave undercut surface. The distal shaft portion may include a second minor diameter, and a second helical thread disposed about the distal shaft portion defining a second major diameter. The second helical thread may include a second concave undercut surface. The first and second concave undercut surfaces may be angled towards the distal end of the shaft. The second minor diameter may be smaller than the first minor diameter and the second major diameter may be smaller than the first major diameter.

A method of preventing bone blowout may include forming a hole in a bone, the hole having a bone hole diameter, and inserting a bone fastener into the hole. The bone fastener may include a shaft having a minor diameter and a helical thread. The helical thread may be disposed about the shaft and may include a first undercut surface and a second undercut surface. The first undercut surface may be angled toward one of the proximal end and the distal end of the shaft, and the second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft. The minor diameter of the shaft may not be greater than 5% larger the bone hole diameter.

A pedicle bone fastener may include a shaft, a helical thread, and an integrated attachment feature. The shaft may include a proximal end, a distal end, and a longitudinal axis. The helical thread may be disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft. The helical thread may include a first undercut surface and a second undercut surface. The first undercut surface may be angled toward one of the proximal end and the distal end of the shaft and the second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft. The integrated attachment feature may be disposed at the proximal end of the shaft and configured to be adjustably secured to a spinal stabilization implement.

Spinal cage devices, systems, and methods of assembly and implanting the devices and systems are disclosed. The cage system includes a cage and at least one locking screw assembly configured to couple to the cage. The spinal cage system includes a cage with a body portion, an external plate, and a rod. The body portion includes at least one opening positioned between the first and second ends, a center opening in the first end, and at least one hole adjacent the center opening. The external plate includes an opening and at least two holes on opposite sides of the opening. The rod extends through the center opening in the cage, the first end configured to couple to the external plate, and the second end positioned in the at least one opening. Methods for assembling a spinal cage system and for implanting a cage system are also disclosed.

Implant assemblies for reverse shoulder arthroplasty are disclosed. In one embodiment, the implant assembly comprises a humeral component, an adaptor fixed to the neck of the humeral component, and a glenosphere bearing component coupled to the adaptor. The glenosphere bearing component comprises a first bearing surface that interfaces with an articulating surface of the adaptor to allow the adaptor to rotate relative to the adaptor and humeral component. The adaptor and the glenosphere bearing component form a locking mechanism that prevents the adaptor from decoupling from the glenosphere bearing component while allowing the adaptor to remain rotatable relative to the glenosphere bearing component after the implant assembly is implanted in the patient The second bearing surface is configured to interface with a glenosphere component to allow the glenosphere bearing component to articulate relative to the glenosphere component.

A laterally deflectable asymmetric implant for implanting into a body may comprise a deflectable piece having distal and proximal ends and assuming a straightened insertion state. The backbone may abut or interconnect with said deflectable piece at the distal end of the deflectable piece. In a fully deflected state the implant may define an asymmetric shape, e.g. a D-shaped loop, defining an at least partially enclosed volume. The deflectable piece may comprise a sequence of segments interconnected at effective hinges. Longitudinal pressure applied to the proximal end of the deflectable piece (or applied to the backbone in an opposite direction) may cause relative longitudinal movement between the backbone and the proximal end of the deflectable piece and may generate outward horizontal movement of the deflectable piece away from the backbone. In one embodiment, the implant is implanted using lateral access into an anterior zone of a vertebra and deployed posteriorly.

A laterally deflectable asymmetric implant for implanting into a body may comprise a deflectable piece having distal and proximal ends and assuming a straightened insertion state. The backbone may abut or interconnect with said deflectable piece at the distal end of the deflectable piece. In a fully deflected state the implant may define an asymmetric shape, e.g. a D-shaped loop, defining an at least partially enclosed volume. The deflectable piece may comprise a sequence of segments interconnected at effective hinges. Longitudinal pressure applied to the proximal end of the deflectable piece (or applied to the backbone in an opposite direction) may cause relative longitudinal movement between the backbone and the proximal end of the deflectable piece and may generate outward horizontal movement of the deflectable piece away from the backbone. In one embodiment, the implant is implanted using lateral access into an anterior zone of a vertebra and deployed posteriorly.

A spinal interbody device, system and method can include use of an interbody cage and plate. The interbody cage can include at least one of a key and a keyway configured to mate with at least one of a mating keyway and key located on the plate. The key and keyway can be configured such that the cage and plate are quickly and easily attached and detached from each other, and such that positional relationship between the cage and plate can be arrived at quickly, accurately, and with tactile and/or audile notice to the practitioner.