METATARSAL ARTHROPLASTY DEVICES, SYSTEMS, AND METHODS
Implants, systems, instruments, methods, and kits for metatarsophalangeal joint arthroplasty may include metatarsal arthroplasty implants, repositioning guides, broach tools, inserter tools, and sterilizable packaging configured to facilitate metatarsal arthroplasty surgical procedures. The metatarsal arthroplasty implants may generally include an articular member having a convex articular surface, a concave bone-facing surface opposite the convex articular surface, and at least one side surface intermediate the convex articular surface and the concave bone-facing surface, as well as a central shaft sized for insertion into a metatarsal bone having a central shaft longitudinal axis, a central shaft proximal end coupled to the concave bone-facing surface of the articular member, and a central shaft distal end extending away from the concave bone-facing surface of the articular member along the central shaft longitudinal axis.
1 . A metatarsal arthroplasty implant comprising:
an articular member comprising:
a convex articular surface;
a concave bone-facing surface opposite the convex articular surface; and
at least one side surface intermediate the convex articular surface and the concave bone-facing surface;
a central shaft sized for insertion into a metatarsal bone comprising:
a central shaft longitudinal axis;
a central shaft proximal end coupled to the concave bone-facing surface of the articular member;
a central shaft distal end extending away from the concave bone-facing surface of the articular member; and
at least one surface feature formed along at least a portion of the central shaft and configured to promote bone in-growth therein.
2 . The metatarsal arthroplasty implant of claim 1 , wherein the at least one surface feature configured to promote bone in-growth comprises at least one of:
a surface roughness feature;
a nano texture feature; and
at least one pore.
3 . The metatarsal arthroplasty implant of claim 2 , wherein the at least one surface feature comprises a plurality pores formed along a proximal portion of the central shaft configured to promote bone in-growth therein.
4 . The metatarsal arthroplasty implant of claim 3 , wherein:
the proximal portion of the central shaft comprises a first width; and
a distal portion of the central shaft comprises a second width,
wherein the first width of the proximal portion is greater than the second width of the distal portion.
5 . The metatarsal arthroplasty implant of claim 4 , wherein the proximal portion of the central shaft comprises substantially circular cross-sectional shapes taken transverse the central shaft longitudinal axis.
6 . The metatarsal arthroplasty implant of claim 5 , wherein the distal portion of the central shaft comprises at least one central shaft barb shaped to resist removal of the central shaft from the metatarsal bone.
7 . The metatarsal arthroplasty implant of claim 1 , wherein:
the articular member further comprises a plurality of notches formed in the at least one side surface with undercut surfaces extending below the convex articular surface configured to facilitate installation and removal of the metatarsal arthroplasty implant from the metatarsal bone.
8 . A metatarsal arthroplasty implant comprising:
an articular member comprising:
a convex articular surface;
a concave bone-facing surface opposite the convex articular surface; and
at least one side surface intermediate the convex articular surface and the concave bone-facing surface; and
a central shaft sized for insertion into a metatarsal bone comprising:
a central shaft longitudinal axis;
a central shaft proximal end coupled to the concave bone-facing surface of the articular member;
a central shaft distal end extending away from the concave bone-facing surface of the articular member along the central shaft longitudinal axis;
an enlarged proximal portion comprising a substantially cylindrical shape; and
a distal portion comprising at least one central shaft barb shaped to resist removal of the central shaft from the metatarsal bone.
9 . The metatarsal arthroplasty implant of claim 8 , wherein:
the enlarged proximal portion of the central shaft comprises a first diameter; and
the distal portion of the central shaft comprises a second diameter,
wherein the first diameter is greater than the second diameter.
10 . The metatarsal arthroplasty implant of claim 8 , wherein the enlarged proximal portion of the central shaft comprises substantially circular cross-sectional shapes taken transverse the central shaft longitudinal axis.
11 . The metatarsal arthroplasty implant of claim 8 , wherein:
the enlarged proximal portion of the central shaft comprises a first length; and
the distal portion of the central shaft comprises a second length,
wherein the second length is greater than the first length.
12 . The metatarsal arthroplasty implant of claim 8 , wherein the central shaft further comprises a transition portion intermediate the enlarged proximal portion and the distal portion of the central shaft.
13 . The metatarsal arthroplasty implant of claim 12 , wherein the transition portion comprises a circular surface.
14 . The metatarsal arthroplasty implant of claim 12 , wherein the transition portion comprises a ramped surface.
15 . The metatarsal arthroplasty implant of claim 12 , wherein at least one of the transition portion and the enlarged proximal portion comprise at least one surface feature configured to promote bone in-growth therein.
16 . A method of performing a revision surgical procedure on a metatarsal bone comprising:
removing a first metatarsal arthroplasty implant from the metatarsal bone, the first metatarsal arthroplasty implant comprising a first central shaft having a first proximal portion with a first diameter; and
inserting a second metatarsal arthroplasty implant into the metatarsal bone, the second metatarsal arthroplasty implant comprising a second central shaft having a second proximal portion with a second diameter,
wherein the second diameter of the second proximal portion is larger than the first diameter of the first proximal portion.
17 . The method of claim 16 , wherein removing the first metatarsal arthroplasty implant from the metatarsal bone further comprises:
grasping at least one notch formed in the first metatarsal arthroplasty implant; and
transmitting at least one extraction force proximally through at least one undercut surface associated with the at least one notch to remove the first metatarsal arthroplasty implant from the metatarsal bone.
18 . The method of claim 16 further comprising:
forming a recess within the metatarsal bone configured to receive the second proximal portion of the second metatarsal arthroplasty implant therein.
19 . The method of claim 18 , wherein forming the recess within the metatarsal bone comprises at least one of:
drilling the recess into the metatarsal bone;
reaming the recess into the metatarsal bone; and
broaching the recess into the metatarsal bone.
20 . The method of claim 16 , wherein inserting the second metatarsal arthroplasty implant into the metatarsal bone further comprises:
engaging a concave abutment surface of an inserter tool against a convex articular surface of an articular member of the second metatarsal arthroplasty implant; and
transmitting at least one insertion force distally through the concave abutment surface of the inserter tool to the convex articular surface of the second metatarsal arthroplasty implant to insert the second metatarsal arthroplasty implant into the metatarsal bone.