ASTM International Standard Specification for Total Knee Prosthesis ASTM F2083-08e1

This specification covers total knee replacement (TKR) prostheses used to provide functioning articulation by employing femoral and tibial components, allowing a minimum of 110' of flexion to high flexion. Replaceable components of modular designs, for example, tibial articulating surfaces and all components labeled for or capable of being used with cement, regardless of whether the same components can also be used without cement are described. Primary and revision prostheses and also covers fixed and mobile bearing knee designs are discussed. Basic descriptions of material and prosthesis geometry are provided. Additionally, those characteristics determined to be important to in vivo performance of the prosthesis are defined. The prostheses are classified into three kinds according to degree of constraint. The first kind is considered constrained which prevents dislocation of the prosthesis in more than one anatomic plane and consists of either a single, flexible, across-the-joint component or more than one component linked together or affined. The second one is a semiconstrained joint prosthesis which limits translation or rotation, or both, of the prosthesis in one or more planes via the geometry of its articulating surfaces. It has no across-the-joint linkages. The third kind is a nonconstrained joint prosthesis which minimally restricts prosthesis movement in one or more planes. Its components have no across-the-joint linkages. The choice of materials is understood to be a necessary but not sufficient assurance of function of the device made from them. All devices shall be fabricated from materials with adequate mechanical strength and durability, corrosion resistance, and biocompatibility.