Partial joint resurfacing implant, instrumentation, and method

An implant, comprising:

• an implant fixation portion including an upper segment and a bone interfacing segment coupled to the upper segment;
• a top articulating portion including a bearing portion and at least one engagement surface positioned on a side opposite the bearing portion;
• and
• a locking mechanism comprising:
• a first locking segment coupled to the upper segment;
• and
• a second locking segment coupled to the at least one engagement surface and structured to engage the first locking segment.

An implant, comprising:

• an implant fixation portion, comprising:
• an upper segment;
• and
• a bone interfacing segment extending out from a bottom surface of the upper segment;
• a top articulating portion, comprising:
• a bearing portion on a top surface of the top articulating portion;
• and
• at least one engagement surface extending out from a bottom surface of the top articulating portion;
• and
• a locking mechanism, comprising:
• a first locking segment coupled to the upper segment, the first locking segment comprising:
• a first portion comprising at least two sidewalls extending from a top surface of the upper segment and into the upper segment;
• a second portion comprising at least two sidewalls and a base, wherein the at least two sidewalls are angled away from the at least two sidewalls of the first portion and to the base, the first portion and second portion forming a channel;
• and
• at least one groove recessed into the upper segment and positioned adjacent to the channel;
• a second locking segment coupled to the at least one engagement surface, the second locking segment comprising:
• a first member extending away from a bottom surface of the top articulating portion;
• a second member extending away from the first member and at least a portion of the second member is larger than the first member, the first member and second member forming a protrusion;
• and
• at least one lip extending away from the bottom surface of the top articulating portion, positioned adjacent to the protrusion, and structured to engage the at least one groove of the first locking segment;
• wherein the locking mechanism comprises at least two channels and at least two protrusions and the at least two channels are structured to couple to the at least two protrusions to secure the top articulating portion to the implant fixation portion.