Subtalar joint implant
AssigneeUCL Business PLC
InventorsAndy Goldberg, Gordon Blunn
Life of this patent
Estimating the term…
Abstract
A subtalar joint implant (20) is disclosed for replacing a natural subtalar joint existing between the talus (102) and calcaneum (104) bones of a patient. In an embodiment the implant comprises talar (22) and calcaneal (24) portions that are configured to slide over each other in the implanted state. The implant is shaped so that the sliding is constrained to trajectories that involve pivoting of the talar portion relative to the calcaneal portion about a pivot point (36) or a line (38) of pivot points.
Claims20
A subtalar joint implant for replacing a natural subtalar joint existing between the talus and calcaneum bones of a patient, the implant comprising:
- a talar portion configured to be rigidly attached to the talus;
- and
- a calcaneal portion configured to be rigidly attached to the calcaneum, wherein, where upper and lower directions are defined relative to the orientation of the implant when implanted in a weight bearing or standing patient:
- a first and a second region of a lower surface of the talar portion are configured to be in contact with respective first and second regions of an upper surface of the calcaneal portion during use;
- the first regions are shaped so as to allow sliding of the first region of the lower surface of the talar portion over the first region of the upper surface of the calcaneal portion;
- and
- the second regions are shaped so as to define a pivot point or line of pivot points and constrain said sliding of the first region of the lower surface of the talar portion over the first region of the upper surface of the calcaneal portion to trajectories that involve pivoting of the talar portion relative to the calcaneal portion about the pivot point or pivot points.
A method of implanting a subtalar joint implant for replacing a natural subtalar joint existing between the talus and calcaneum bones of a patient,
- wherein the implant comprises:
- a talar portion configured to be rigidly attached to the talus;
- and
- a calcaneal portion configured to be rigidly attached to the calcaneum, wherein, where upper and lower directions are defined relative to the orientation of the implant when implanted in a weight bearing or standing patient:
- a first and a second region of a lower surface of the talar portion are configured to be in contact with respective first and second regions of an upper surface of the calcaneal portion during use;
- the first regions of the lower and upper surfaces are shaped so as to allow sliding of the first region of the lower surface over the first region of the upper surface;
- and
- the second regions of the lower and upper surfaces are shaped so as to define a pivot point or line or pivot points and constrain said sliding of the first region of the lower surface over the first region of the upper surface to trajectories that involve pivoting of the talar portion relative to the calcaneal portion about the pivot point or pivot points,
- wherein the method comprises:
- preparing a space between the talus and calcaneum that is suitable for accommodating the implant;
- implanting the implant in the space in such a way that, when viewed from above, the first regions overlap with a region where the posterior facet of the subtalar joint was located prior to implantation of the implant and the second regions overlap with a region where the middle facet of the subtalar joint was located prior to implantation of the implant.
Dependencies are inferred from the claim text.