Subtalar implant for arthroereisis of the talocalcaneal joint

A subtalar implant for arthroereisis of the talocalcaneal joint, the implant configured to be inserted into the talocalcaneal joint via its lateral orifice, the implant being one-piece and comprising:

• an oblong shape that extends longitudinally along an axis of insertion of the implant;
• a head having a shape of a cone of revolution centred on the axis of insertion;
• an anchoring thread;
• a rod having a shape of a cylinder of revolution centred on the axis of insertion, the rod having, on its surface, the anchoring thread and being arranged to be inserted up to the axis of rotation of the talocalcaneal joint, the head flaring out from the rod and being located upstream of the head along the axis of insertion of the implant, the head having, on its radially outer surface, retaining elements for retaining the implant in rotation about the axis of insertion, the retaining elements being arranged to exert retention against a colonising tissue, wherein the retaining elements comprise:
• a plurality of depressions with respect to the shape of the cone of revolution of the head;
• at least one recess located inside each of the depressions, the at least one recess communicating with the at least one recess of at least one other of the plurality of depressions inside the head in order to create at least one annular cavity to be colonised by colonising tissue, each of the plurality of recesses having a bottom, which is flat,
• wherein, in a transverse cross-section perpendicular to the axis of insertion:
• the head is inscribed inside a first polygon, wherein sides of which extend at the depressions;
• for each of the at least one annular cavity, the bottoms of the recesses of that annular cavity joined end to end have a shape of a second polygon such that the annular cavity has a polygonal shape, suitable for allowing inscription of a fibrous integration polygon inside the head.