Marker for tracking objects in medical procedures
Tracking objects in medical procedures. At least one example is a method comprising: retaining a bone marker on a distal end of an installation tool, the bone marker comprising a polyhedron having a fiducial pattern on each of at least three outward facing surfaces of the polyhedron, an externally-threaded screw extending distally from the polyhedron, and a flange proximate to an intersection of the polyhedron and the externally-threaded screw; positioning a distal end of the externally-threaded screw against a bone at a marker location; screwing the externally-threaded screw into the bone by way of the installation tool; and trapping tissue against the bone beneath the flange.
1 . A method comprising:
retaining a bone marker on a distal end of an installation tool, the bone marker comprising a polyhedron having a fiducial pattern on each of at least three outward facing surfaces of the polyhedron, an externally-threaded screw extending distally from the polyhedron, and a flange proximate to an intersection of the polyhedron and the externally-threaded screw;
positioning a distal end of the externally-threaded screw against a bone at a marker location;
screwing the externally-threaded screw into the bone by way of the installation tool; and
trapping tissue against the bone beneath the flange.
2 . The method of claim 1 wherein trapping tissue against the bone further comprises trapping tissue between an exterior surface of the bone and a bottom face of the flange being a polymeric material.
3 . The method of claim 1 wherein trapping tissue against the bone further comprises trapping tissue between an exterior surface of the bone and a bottom face of the flange being a metallic material.
4 . The method of claim 1 wherein trapping the tissue against the bone further comprises trapping the tissue with the flange, and a vector normal to a plane defined by a portion of flange beneath the polyhedron forms an acute angle with a longitudinal central axis of the externally-threaded screw.
5 . The method of claim 1 wherein trapping tissue against the bone further comprises trapping tissue between an exterior surface of the bone and a bottom face of the flange defining at least one outside shape consisting of: circular; and oblong.
6 . The method of claim 1 wherein retaining the bone marker further comprises:
telescoping the polyhedron into an internal volume at the distal end of the installation tool, the bone marker comprising a retention bore having an entrance aperture through an upper face of the polyhedron; and
placing a retention fastener within the retention bore, the retention fastener retains the bone marker in a mating relationship with the installation tool.
7 . The method of claim 6 further comprising, after screwing the externally-threaded screw into the bone, removing the retention fastener from within the retention bore.
8 . The method of claim 6 wherein screwing the externally-threaded screw into the bone further comprises applying force to the flange to the exclusion of the polyhedron.
9 . The method of claim 6 wherein placing the retention fastener within the retention bore further comprises threading external threads of the retention fastener into mating relationship with internal threads of the retention bore.
10 . The method of claim 9 further comprising, after screwing the externally-threaded screw into the bone, unscrewing the external threads of the retention fastener from the internal threads of the retention bore.
11 . The method of claim 6 wherein screwing the externally-threaded screw into the bone further comprises applying force to the at least three outward facing surfaces of the polyhedron.
12 . The method of claim 11 wherein applying force to the at least three outward facing surfaces of the polyhedron further comprises applying force at a location on each of the at least three outward facing surfaces that does not overlap the respective fiducial pattern on each of the at least three outward facing surfaces.
13 . A bone marker comprising:
a polyhedron defining a first outward-facing surface, a second outward-facing surface, and a third outward-facing surface;
an externally-threaded screw projecting from a side of the polyhedron, the externally-threaded screw and polyhedron are monolithic;
a retention bore having an entrance aperture through the polyhedron, the retention bore defining a retention feature on an inside surface of the retention bore;
a first fiducial pattern on the first outward-facing surface, a second fiducial pattern on the second outward-facing surface, and a third fiducial pattern on the third outward-facing surface, the first, second, and third fiducial patterns distinct from each other; and
a flange disposed proximate to an intersection of the polyhedron and the externally-threaded screw.
14 . The bone marker of claim 13 wherein the polyhedron is a cube.
15 . The bone marker of claim 13 wherein the externally-threaded screw is a self-tapping screw.
16 . The bone marker of claim 13 wherein the first, second, and third fiducial patterns are each three dimensional patterns.
17 . The bone marker of claim 13 wherein the retention feature further comprises threads defined on an inside surface of the retention bore.
18 . The bone marker of claim 17 wherein the externally-threaded screw comprises right-handed threads, and the threads on the inside surface of the retention bore comprises left-handed threads.
19 . The bone marker of claim 13 wherein the flange further comprises a polymeric material defining a top surface, a bottom surface opposite the top surface, a throughbore defining a throughbore axis, and a thickness measured parallel to throughbore axis, the throughbore telescoped over the externally-threaded screw, and the flange disposed at the intersection of a bottom face of the polyhedron and the proximal end of the externally-threaded screw.
20 . The bone marker of claim 19 wherein the flange comprises at least one material selected from a group consisting of: polymeric material; metallic material; and silicone.
21 . The bone marker of claim 19 wherein the flange further comprises at least one shape selected from a group consisting of: circular; and oblong.
22 . The bone marker of claim 19 further comprising:
an annular trough disposed at the intersection of the polyhedron and a proximal end of the externally-threaded screw, the annular trough circumscribing a longitudinal central axis of the externally-threaded screw; and
an inside diameter of the throughbore of the flange forming a friction fit with the annular trough.
23 . The bone marker of claim 19 further comprising:
an annular trough disposed at the intersection of the polyhedron and a proximal end of the externally-threaded screw, the annular trough circumscribing a longitudinal central axis of the externally-threaded screw;
an installation thread defined between threads of the externally-threaded screw and the annular trough; and
an inside diameter of the throughbore disposed within the annular trough.
24 . The bone marker of claim 13 wherein the flange further comprises:
an upper surface that intersects the first, second, and third outward-facing surfaces;
a lower surface that intersects the externally-threaded screw;
a diameter greater than a largest dimension of the polyhedron measured perpendicular to a longitudinal central axis of the externally-threaded screw; and
the flange, the polyhedron, and the externally-threaded screw are monolithic.
25 . The bone marker of claim 24 further comprising an interface feature defined by the flange, the interface feature being at least one selected from a group consisting of: an outside surface of the flange; an indention on the upper surface of the flange.