Joint implants with interface surfaces having registration features

An interphalangeal joint implant, comprising:

• a proximal joint implant element having a proximal curved interface surface and a proximal base portion, wherein the proximal curved interface surface comprises a plurality of proximal registration features;
• a distal joint implant element rotatably coupled to the proximal joint implant element, the distal joint implant element having a distal curved interface surface facing the proximal curved interface surface and having a distal base portion, wherein the distal curved interface surface comprises a plurality of distal registration features that are complementary to the proximal registration features such that the distal registration features and the proximal registration features directly interface with one another to maintain registration between the proximal and distal joint implant elements through a range of rolling motion of the proximal and distal joint implant elements relative to one another;
• a proximal bone interface connector connected to the proximal base portion, the proximal bone interface connector sized and configured to be implanted into a phalanx bone;
• a distal bone interface connector connected to the distal base portion, the distal bone interface connector sized and configured to be implanted into a phalanx bone;
• and
• a joint implant element connector comprising a connector base positioned in slots formed in central portions of the proximal joint implant element and the distal joint implant element, a proximal pin supporting the proximal joint implant element, and a distal pin supporting the distal joint implant element such that the distal curved interface surface interfaces with the proximal curved interface surface through the range of motion of the proximal and distal joint implant elements relative to one another;
• wherein at least one of the proximal curved interface surface or the distal curved interface surface comprises a protrusion that prevents rotation of the proximal joint implant element with respect to the distal joint implant element upon the protrusion contacting the other of the proximal curved interface surface or the distal curved interface surface, such that the protrusion restricts a range of motion of the relative rotation of the proximal joint implant element and the distal joint implant element;
• wherein the proximal pin extends transversely through the proximal curved interface surface and through the connector base along the rotational axis of the proximal joint implant element, and wherein the distal pin extends transversely through the distal curved interface surface and through the connector base along the rotational axis of the distal joint implant element.