TOTAL CONSTRICTED ELBOW PROSTHESIS MADE OF SHAPE-MEMORY ALLOY WITH HINGE-LIKE FIXATION AND COUPLING SYSTEM BASED ON SHAPE-MEMORY EFFECT

摘要

The invention relates to a total constricted elbow prosthesis made of biocompatible shape-memory metal materials and polymer materials, the prosthesis being meant to replace the human elbow joint affected as a consequence of accidents or bone and joint diseases. The claimed prosthesis comprises an ulnar component (1) made of CoCr, TiAlV, TiNi alloys or other equivalent alloys, which is fixed in the medullary channel of the ulna and consists of a fixation rod of truncated pyramid shape with a length of 50...200 mm, with a square-shaped end cross-section with a side of 7...20 mm and an angle of flaring of 1...5° towards some attachment eyelets, with rounded edges, with an end with rounded edges and a transverse cylindrical end having a diameter of 7...20 mm and a length of 10...30 mm, the passage from the rod to the cylinder being carried out smoothly, by means of connections, the transverse cylindrical end being symmetrically continued in both directions with two cylindrical axles with a radius of 4...10 mm and a length of 7...20 mm on which some polymer or ceramic rings (2 and 3) will be fixed, each axle ending with a disk with rounded borders having a diameter of 9...25 mm and a thickness of 2.5...4 mm which limits without blocking the axial displacement of the humeral component (4) which is fixed on the humeral bone and which comprises a fixation rod with a length of 50...200 mm, with a square-shaped end cross-section with a side of 3...10 mm and an angle of flaring of 1...5° towards some attachment eyelets, an element of support on the bone with a length of 10...20 mm, having an intermediary paralellepipedal element and some attachment eyelets which remain in the closed position, being wound on the rotation axle of the ulnar component (1), at a temperature slightly below the temperature of the human body, i.e. 30...33°C and being unwound into open position at low temperatures of 1...2°C, for revision.