Metatarsophalangeal joint implants and methods thereof
Systems, methods, and devices described herein relate an implant adapted to be placed in a bone in the metatarsophalangeal joint or a metacarpophalangeal joint. In some embodiments, the implant includes a head portion extending from a first surface to a second surface and having a plurality of layers located between the first surface and the second surface. In some embodiments, the first surface is lubricious. In some embodiments, the implant comprises a post portion extending from the second surface of the head portion to a bone facing surface.
1 . A method for disposing an implant at least partially into a metatarsal bone in a metatarsophalangeal joint, the method comprising the steps of:
disposing a recess through an articular surface of a metatarsal head of the metatarsal bone such that the metatarsal head maintains articulation with a sesamoid bone;
inserting an alignment pin into the recess; and
inserting the implant into the metatarsal bone at an angle between 15-30 degrees with respect to a longitudinal axis of the metatarsal bone;
wherein the implant comprises a head portion and a post portion extending from the head portion, the implant further comprises a cavity at least partially disposed into a distal end of the post portion, and the cavity extends along a longitudinal axis of the post portion.
2 . The method of claim 1 , wherein the implant further comprises a foot portion extending from the head portion towards a distal end of the foot portion, thereby creating an articulating surface with a phalangeal bone.
3 . The method of claim 1 , wherein the recess is formed by contacting a distal end of a drill bit with the articular surface of the metatarsal head of the metatarsal bone, and wherein the method further comprises the steps of:
forming a first cavity of the recess with a first drill bit portion having a first drill bit diameter about equal to a diameter of the post portion of the implant; and
forming a second cavity of the recess with a second drill bit portion having a second drill bit diameter about equal to a diameter of the head portion of the implant, wherein a distal end of the first drill bit portion extends distally from a distal end of the second drill bit portion, and wherein the first drill bit diameter is smaller than the second drill bit diameter.
4 . The method of claim 3 , wherein the drill bit comprises a depth guide configured to contact a drill guide when the drill bit reaches a final depth of the recess.
5 . The method of claim 1 , further wherein the implant comprises a post extension having a first end configured to be at least partially disposed in the metatarsal bone and a second end configured to couple with the cavity of the post portion.
6 . The method of claim 2 , wherein a first surface of the head portion extends along a length of the foot portion.
7 . The method of claim 1 , wherein a first surface of the head portion is convex having a substantially spherical curvature.
8 . The method of claim 1 , wherein a first surface of the head portion comprises a first curvature and a second curvature.
9 . The method of claim 8 , wherein the first curvature has a more acute angle than the second curvature.
10 . The method of claim 1 , further comprising visually evaluating a pin guide against the articular surface, such that the pin guide has a diameter that is equal to a diameter of the recess, wherein the pin guide makes three points of contact against the articular surface.
11 . The method of claim 1 , wherein the alignment pin is inserted into the recess to a depth of 30-50 mm.
12 . A method for disposing an implant at least partially into a metatarsal bone in a metatarsophalangeal joint, the method comprising the steps of:
disposing a recess through an articular surface of a metatarsal head of the metatarsal bone such that the metatarsal head maintains articulation with a sesamoid bone; and
inserting the implant into the metatarsal bone at an angle between 15-30 degrees with respect to a longitudinal axis of the metatarsal bone; and
inserting a trial implant into the recess to visually inspect a relative location of the articular surface and the trial implant;
wherein the trial implant comprises a defined etched band disposed along a circumference of the trial implant.
13 . The method of claim 12 , wherein the articular surface is located proximally to a distal border of the defined etched band and distally to a proximal border of the defined etched band when the trial implant is inserted into the recess.
14 . The method of claim 12 , wherein the articular surface is aligned with a proximal edge of the defined etched band when the trial implant is inserted into the recess.
15 . The method of claim 12 , wherein the implant comprises a head portion and a post portion extending from the head portion, wherein the implant further comprises a foot portion extending from the head portion towards a distal end of the foot portion, thereby creating an articulating surface with a phalangeal bone.
16 . The method of claim 15 , wherein a first surface of the head portion extends along a length of the foot portion.
17 . The method of claim 12 , wherein the recess is formed by contacting a distal end of a drill bit with the articular surface of the metatarsal head of the metatarsal bone, and wherein the method further comprises the steps of:
forming a first cavity of the recess with a first drill bit portion having a first drill bit diameter about equal to a diameter of the post portion of the implant; and
forming a second cavity of the recess with a second drill bit portion having a second drill bit diameter about equal to a diameter of the head portion of the implant, wherein a distal end of the first drill bit portion extends distally from a distal end of the second drill bit portion, and wherein the first drill bit diameter is smaller than the second drill bit diameter.
18 . The method of claim 17 , wherein the drill bit comprises a depth guide configured to contact a drill guide when the drill bit reaches a final depth of the recess.
19 . The method of claim 12 , further wherein the implant comprises a post extension having a first end configured to be at least partially disposed in the metatarsal bone and a second end configured to couple with the cavity of the post portion.
20 . The method of claim 12 , wherein the implant comprises a head portion and a post portion extending from the head portion, wherein a first surface of the head portion is convex having a substantially spherical curvature.
21 . The method of claim 12 , wherein the implant comprises a head portion and a post portion extending from the head portion, wherein a first surface of the head portion comprises a first curvature and a second curvature.
22 . The method of claim 21 , wherein the first curvature has a more acute angle than the second curvature.
23 . A method for disposing an implant at least partially into a metatarsal bone in a metatarsophalangeal joint, the method comprising the steps of:
disposing a recess through an articular surface of a metatarsal head of the metatarsal bone such that the metatarsal head maintains articulation with a sesamoid bone; and
inserting the implant into the metatarsal bone at an angle between 15-30 degrees with respect to a longitudinal axis of the metatarsal bone;
wherein the metatarsal head comprises at least 2 mm of bone surrounding the recess;
wherein the recess is formed by contacting a distal end of a drill bit with the articular surface of the metatarsal head of the metatarsal bone, and wherein the method further comprises the steps of:
forming a first cavity of the recess with a first drill bit portion having a first drill bit diameter about equal to a diameter of the post portion of the implant; and
forming a second cavity of the recess with a second drill bit portion having a second drill bit diameter about equal to a diameter of the head portion of the implant, wherein a distal end of the first drill bit portion extends distally from a distal end of the second drill bit portion, and wherein the first drill bit diameter is smaller than the second drill bit diameter.
24 . The method of claim 23 , wherein the drill bit comprises a depth guide configured to contact a drill guide when the drill bit reaches a final depth of the recess.
25 . A method for disposing an implant at least partially into a metatarsal bone in a metatarsophalangeal joint, the method comprising the steps of:
disposing a recess through an articular surface of a metatarsal head of the metatarsal bone such that the metatarsal head maintains articulation with a sesamoid bone; and
inserting the implant into the metatarsal bone at an angle between 15-30 degrees with respect to a longitudinal axis of the metatarsal bone;
wherein the metatarsal head comprises at least 2 mm of bone surrounding the recess;
further wherein the implant comprises a post extension having a first end configured to be at least partially disposed in the metatarsal bone and a second end configured to couple with a cavity within the post portion.