A bone anchor includes an anchor member including a first material, and having a tubular section extending along a longitudinal axis, a region configured to expand radially outwards from the longitudinal axis, and a bone engagement structure projecting from at least a portion of the expandable region of the tubular section, and a core member including a second material, and configured for insertion into and connection to the anchor member. When the core member is in the anchor member and is actuated relative to the anchor member, the tubular section is adjustable between a first position where the expandable region of the tubular member has a first length and a first maximum diameter, to a second position where the expandable region of the tubular member has a length shorter than the first length and a maximum diameter greater than the first maximum diameter.

A multiple drive interference screw device with a head having multiple insertion features. The screw component has a tubular body with a first end and a closed second end, and the head is positioned at the first end and configured to engage with a driver to advance the screw into the bone A penetrating tip is positioned at the second end. The head of the screw component has at least three insertion features, such as a hex shaped insertion feature around the major diameter of the head and a hexalobe shaped insertion feature within the hex shaped insertion feature, and a sprocket shaped insertion feature positioned exterior to the hex shaped insertion feature.

A compression screw comprising a threaded shaft and a head associated with the proximal end of the shaft. The head has a plurality of outwardly extending projections spaced from one another so as to define a plurality of recesses there between for receiving a screw drive in such a way that rotational force may be transferred from the screw drive to the screw. The projections of the head may be provided with suture fixation holes or a suture coupling may be positioned over the shaft so as to extend between the projections of the head.

Disclosed is a fixation system and method. The system and method may fix a selected member to a subject during a procedure. The selected member may include a tracking device or registration member.

A bone fastener includes a head, and a screw portion extends from the head. The screw portion includes a shaft and a thread extending along and about the shaft. The thread has a height extending from a root to a tip thereof. The thread also has first and second portions disposed between the root and the tip. The second portion has a porous structure configured to promote bone ingrowth and has a porosity greater than that of the first portion.

A bone fixation system with variable z-axis translation is provided. The system includes an outer tulip coupled to a bone fastener via a screw retainer. An inner tulip is coupled to the outer tulip such that the inner tulip is longitudinally movably relative to the outer tulip. The inner tulip includes a lock that provides a seat for a connecting rod. The inner tulip together with a seated rod is permitted to translate along the z-axis inside the outer tulip when in an unlocked position. Also in the unlocked position, the bone fastener is free to angulate relative to the outer tulip. The z-axis position of the inner tulip and rod relative to the outer tulip is fixed in a locked position. Also, in the locked position, the bone fastener is locked with respect to the outer tulip. The system may be adjusted between the locked and unlocked positions by way of a set screw.

A fixation device includes a head, a tapered body coupled to the head and extending along a central longitudinal axis, and a flexible tail extending distally from the tapered body and defining a central bore therethrough. The flexible tail is movable from an initial configuration aligned with the central longitudinal axis to a deflected configuration that extends away from the central longitudinal axis when a force is applied to the flexible tail.

A screwdriver assembly includes a screwdriver shaft and an insert. The screwdriver shaft extends longitudinally from a proximal end to a distal end and having a longitudinal channel extending therethrough. The insert has a longitudinal shaft received within the longitudinal channel and a distal end extending distally relative to the distal end of the screwdriver shaft. The insert shaft is rotatable relative to the screwdriver shaft. The distal end of the insert is sized and shaped to engage a head of a screw. The distal end of the insert is disengaged from the screw head by rotating the insert relative to the screwdriver shaft.

A subtalar arthroereisis screw may have a head and a body with a distal tip, a shank extending from the head to the distal tip, and a screw thread extending along the shank. The shank may have a leading end proximate the distal tip and a trailing end proximate the head. The screw thread may be continuously variable between a first pitch relatively closer to the trailing end, and a second pitch, larger than the first pitch, relatively closer to the leading end. The head may have a receiving end that is connectable to a tool to facilitate rotation of the head with the tool during implantation of the subtalar arthroereisis screw. The screw thread may taper continuously from a first major diameter at the trailing end, to a second major diameter, smaller than the first major diameter, and may have a plurality of notches distributed along its length.

Various surgical tools having a movable handle mechanism including a positioning handle are disclosed. The movable handle mechanism may be configured to move forward and backward in a longitudinal direction along the housing and rotate clockwise and counterclockwise around the housing. In various embodiments, the housing may include a plurality of channels and each channel may have at least one detent. The movable handle mechanism may be configured to securely couple to the housing via one channel of the plurality of channels and one detent of the plurality of detents. At least one surgical tool may include a drill having an angled tip portion and a sleeve configured to protect adjacent structures from lateral edges of the drill bit when the drill bit is rotating. Another surgical tool may include a screwdriver having an elastic retaining clip configured to progressively release a bone screw therein at an extraction force.