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US 4,921,499 AGranted
Adjustable prosthesis
AssigneeOrdev B.V.
InventorsErik L. Hoffman, Antonius L. J. Hopstaken
Life of this patent
Estimating the term…
Abstract
A fixation element for securing a prosthesis in a bone, whereby the effective diameter of the fixation element can be increased by increasing the temperature of at least one element of a material which shrinks or expands when heated, such as shape memory metal, by means of an inductive magnetic field, whereby the change in shape generated with the shrinkage or expansion of the material is converted into an increase in diameter of the fixation element.
Claims6
A fixation element for securing a prosthesis in a bone, said element comprising:
- a tapered core adapted to be secured to a prosthesis;
- a substantially cylindrical sleeve configured to surround said core, said sleeve defining a plurality of discrete segments, each of said segments having an inner surface complementary tapered to engage the tapered core;
- a plurality of shape memory metal rods each having a transition temperature and being capable of changing shape in response to a change in temperature above or below the transition temperature;
- and
- said rods extending between and interconnecting the core and each of the segments, whereby a change in shade of the rods is converter into an increase in diameter of the fixation element so as to effect a secure fixation of the prosthesis in the bone.
2 more elements
A fixation element for securing a prosthesis in a bone, said element comprising:
- a first element having a first wedge shaped surface;
- a second element configured to surround said first element and having an inner second surface with a complementary wedge shape to engage said first surface;
- at least one shape memory rod having a transition temperature and being capable of changing shape in response to a change in temperature above or below the transition temperature;
- and
- said rod being arranged with respect to said first and second elements such that the change in the shape of the rod is converted into relative motion between said first and second elements so as to produce an increase in diameter of the fixation element thereby effecting a secure fixation in the bone of the fixation element and a prosthesis connected thereto.
2 more elements
Dependencies are inferred from the claim text.