Modular orthopedic implants, associated instruments, and navigation methods. The modular orthopedic fixation assembly may include a modular bone fastener and a modular tulip head configured to be installed separately. The modular bone fastener may be installed and tracked with a screw extender instrument having an outer sleeve and an inner shaft coupled to the bone fastener. The screw extender instrument may continue to track the location and orientation of the bone throughout the surgical procedure for navigational integrity. The modular tulip head may be assembled to the bone fastener with a head inserter instrument, which ensures the modular head is properly seated on the installed bone fastener.

An implantable body for a posterior stabilization system includes a lateral end, a medial end, an inwardly facing surface configured to abut against a lamina when the body is implanted along a vertebra. A lateral bone outrigger extends from the inwardly facing surface and may include a bone-abutting surface along a medial portion disposed to abut against a lateral mass of the vertebra when the body is implanted along a vertebra. The lateral bone outrigger may have a first height. A penetrating feature extends from the inwardly facing surface between the bone-engaging portion of the inwardly facing surface and the lateral bone outrigger. The penetrating feature may have a second height less than the first height. A fastener bore extends through the body at an angle toward the lateral bone outrigger.

A modular spinal fixation system for securing an elongate rod to a bone of a patient includes a plurality of bone anchors, each having a universal shank head and an anchor portion opposite the universal shank head configured for fixation to the bone. The system further includes a plurality of pivoting and non-pivoting receiver sub-assemblies, with each receiver sub-assembly including a receiver having an upper portion defining a channel configured to receive the elongate rod and a base defining a lower portion of a central bore communicating with a bottom surface of the receiver through a bottom opening, and one of a shank head-engaging retainer or a rod-engaging insert positioned within the central bore. Each of the universal shank heads is configured for uploading into both the pivoting and non-pivoting receiver sub-assemblies through the bottom opening of the receiver and for axial rotation about a longitudinal axis of the shank relative to the receiver prior to locking the receiver sub-assembly to the head of the shank with the elongate rod and a closure.

A fastener device includes an anchor body that defines a through hole. The anchor body further includes an inner surface that defines a least a portion of the through hole. The fastener includes a head, a threaded shaft that extends out with respect to the head in a distal direction, and a neck between the head and threaded shaft. The head includes an outer surface configured to articulate along the inner surface when the fastener head is inserted in the through hole. At least a portion of the outer surface is convex and defines a portion of a sphere that defines a first diameter. The neck defines a second diameter and the fastener defines a ratio of the first diameter to the second diameter in a range between about 2 to 1 and about 3 to 1.

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.

A modular screw assembly for use in stabilizing a spinal column. The assembly has a fastener which couples to a screw head of a bone anchor, a screw head coupler, a retaining ring, and a friction ring. The fastener houses the screw head coupler, the retaining ring, and the friction ring. Translation of the fastener by the screw head results in the retaining ring elastically deforming and then snapping around the screw head.

Orthopedic fixation devices and methods of installing the same. The orthopedic fixation device may include a coupling element and a bone fastener, whereby the bone fastener can be loaded into the coupling element through the bottom of a bore in the coupling element and a retention member is configured to allow polyaxial rotation of the bone fastener and also to lock the bone fastener in place upon application of a force on a saddle and clamp in the coupling element.

Connector assemblies, systems, and methods thereof. A connector has a first end that clamps to a first rod in an existing construct and a second end, connected to the first end, that clamps to a second rod in a new construct such that the new construct can be extended from the existing construct at an adjacent level as the existing construct.

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.

An internal fixation member set includes an internal fixation member, an inner member, and an outer member. The outer member has a first opening and a second opening, and rotatably retains a head of the inner fixation member. The inner member is inside the outer member and movable between a first position farther from the head and a second position nearer the second opening than the first position. The head has a first rotation range with the inner member at the first position and a second rotation range with the inner member at the second position. The second rotation range is smaller than the first rotation range with an interference between interference parts. A reference rotational position at which the head is insertable into or extractable from the outer member is included in the first rotation range and is not included in the second rotation range.