Abstract: An artificial joint is characterized by: having a first member including a caput part on which a prescribed curved surface is formed, and a second member including a fossa part having a surface which abuts the prescribed curved surface of the caput part; the second member being rotatable in a flexing direction of a joint with a prescribed point on the caput part being the center of rotation; and the prescribed curved surface of the caput part being defined by a curve which depicts a convex arc toward the side abutting the fossa part when the caput part is viewed from the axial direction of the rotation, and in which, when two arbitrary points are taken on the curve, the radius of curvature of the point positioned further toward the flexing side of the joint on the curve is smaller than the radius of curvature of the other point.

Abstract: The present invention provides a precursor for producing a tissue regenerating instrument that regenerates a tissue, including: a tube made of a biodegradable material provided with a lumen in a longitudinal direction; a rod made of a biodegradable material swellable with a softening solvent, fixed to an inner wall of the tube substantially parallel to the longitudinal direction of the tube; and an adhesive that fixes the rod to the inner wall of the tube, in which the rod in a non-swelled state has an occupied cross-sectional area perpendicular to the longitudinal direction that is smaller than a cross-sectional area of the lumen of the tube, and the occupied cross-sectional area perpendicular to the longitudinal direction of the rod in a saturated swelled state with the softening solvent is substantially the same as the cross-sectional area of the lumen of the tube.

Abstract: The present invention provides a precursor for producing a tissue regenerating instrument that regenerates a tissue, including: a tube made of a biodegradable material provided with a lumen in a longitudinal direction; a rod made of a biodegradable material swellable with a softening solvent, fixed to an inner wall of the tube substantially parallel to the longitudinal direction of the tube; and a fixing means that fixes the rod to the inner wall of the tube, in which the rod in a non-swelled state has a occupied cross-sectional area perpendicular to the longitudinal direction is smaller than a cross-sectional area of the lumen of the tube, and the occupied cross-sectional area perpendicular to the longitudinal direction of the rod in a saturated swelled state with the softening solvent is substantially the same as the cross-sectional area of the lumen of the tube.