Abstract: Embodiments of the invention provide intramedullary nail assemblies that provide particularly good internal fixation, are particularly easy to deploy, or both. Embodiments also provide methods of using such nail assemblies.

Abstract: Methods and apparatuses for fixing a bone fragment or a bone prosthesis onto a bone. To affix a bone fragment to the bone, an internal fastener is attached from within the interior of the bone to a bone fragment with a length of flexible, inelastic cord extending within the bone interior and attached to the fastener and passing outwardly through an opening in a second bone fragment. An axially rigid tubular support may be placed along the cord to reduce particulate shedding, to reduce ingrowth of bone into the cord, to provide compressive resistance to the cable, or to deliver antibiotics or other pharmaceuticals. The fastener and cord are so positioned as to draw respective fracture surfaces together to reduce the fracture when the cord is pulled outwardly of the opening in the second bone fragment. A second fastener desirably is attached to the bone opening, this fastener including an open bore to receive the cord and a lock to secure the cord to this fastener and maintain the cord under tension.

Abstract: Methods and apparatuses for fixing a bone fragment or a bone prosthesis onto a bone. To affix a bone fragment to the bone, an internal fastener is attached from within the interior of the bone to a bone fragment with a length of flexible, inelastic cord extending within the bone interior and attached to the fastener and passing outwardly through an opening in a second bone fragment. The fastener and cord are so positioned as to draw respective fracture surfaces together to reduce the fracture when the cord is pulled outwardly of the opening in the second bone fragment. A second fastener desirably is attached to the bone opening, this fastener including an open bore to receive the cord and a lock to secure the cord to this fastener and maintain the cord under tension.

Abstract: A ball (14) and cup (18) prosthesis is provided with articulating metal surfaces (25, 24), the surfaces (25, 24) having an area of intimate contact (.theta.) in which the surfaces (25, 24) are formed on radii (R.sub.3, R.sub.1) which differ by at most 50 micrometers. The area of intimate contact (.theta.) has a surface area that ranges from 0.12 .pi.R.sub.3.sup.2 to 1.65 .pi.R.sub.3.sup.2, and the centerline average surface roughness of the metal articulating surfaces (25, 24) in the area of intimate contact (.theta.) preferably is not greater than 0.1 micrometers.

Abstract: A joint prosthesis for replacing a joint between two elongated bones of the hand. A first member is provided with an elongated stem for reception in one of the elongated bones and includes a head remote from the stem, the head having a central arcuate dovetail rib arising from a spheroidal convex articulating surface. A second member has a stem for reception in the other bone and a base remote from the stem, the base having a central arcuate dovetail slot formed in a spheroidal concave surface shaped to articulate with the convex articular surface. The central arcuate dovetail rib of the first member and arcuate dovetail slot of the second member are assembled to fully engage and articulate with each other to restrain separation of the members at all degrees of flexion ranging from 0 degrees extension through to 110 degrees of flexion, the force between the members being borne primarily by said spheroidal articular surfaces throughout the range of motion.

Abstract: A joint prosthesis for replacing a joint between two elongated bones of the hand. A first member is provided with an elongated stem for reception in one of the elongated bones and includes a head remote from the stem, the head having a convex articulating surface and lateral articulating surfaces adjacent the convex surface and on each side thereof. A second member has a stem for reception in the other bone and a base remote from the stem, the base having a concave articulating surface and lateral articulating surfaces on each side thereof, the concave and lateral surfaces being adapted to engage and articulate with the respective convex and lateral articulating surfaces of the first member.

Abstract: A joint prosthesis is provided for replacing a joint between two bones in which one bone is normally permitted a substantial degree of rotary circumduction with respect to a second bone. A first member of the prosthesis is provided with a coupling portion enabling it to be attached to the elongated bone and includes a head having a generally saddle-shaped articulating surface facing away from the stem. The second member similarly has a connector adapted to connect the second member to the second bone, and has a head provided with a saddle-shaped articulating surface configured and sized to articulate with the saddle-shaped surface of the first member to enable one of the long bones to move in rotary circumduction with respect to the other. The saddle-shaped surfaces preferably are substantially congruent in shape.