Abstract: The present invention relates to an artificial synovial fluid composition that mimics the tribological and biochemical properties of human, osteoarthritic synovial fluid for in vitro testing of implantable materials. The artificial synovial fluid comprises new-born calf serum or alpha-calf serum (iron-free or iron-supplemented) that contains a specific total protein concentration, specific protein constituent fractions (albumin, ?-1 globulin, ?-2 globulin, ?-globulin, and ?-globulin), specific trace element concentrations (Ca, Mg, inorganic P, and Fe), and a specific low-molecular weight peptide concentration important for in vitro testing of implantable materials. In addition, the artificial synovial fluid contains a hyaluronic acid concentration and level of osmolality (preferably using phosphate buffered-saline solution) to mimic the thermal stability (transition mid-point temperature, enthalpy, and entropy) and pH level as measured clinically.

Abstract: A prosthetic knee system includes a tibial tray, a non-rotating tibial insert, and a rotating tibial insert. The non-rotating tibial insert and the rotating tibial insert are selectively coupleable to the tibial tray such that a fixed or a mobile orthopaedic prosthesis may be configured. In some embodiments, the tibial tray may be a fixed or mobile tibial tray. Additionally, in some embodiments, the prosthetic knee system may include a femoral component.

Abstract: The present invention relates to an artificial synovial fluid composition that mimics the tribological properties of human, osteoarthritic synovial fluid (SF) for the main purpose of in vitro wear testing. There is described an artificial synovial fluid composition comprising: a) a mammalian serum having i) a total protein concentration of from about 10 to about 45 g/L; ii) an albumin fraction of from about 55% to about 80% w/w %; iii) an ?-1 globulin fraction of from about 3% to about 6% w/w %; iv) an ?-2 globulin fraction of from about 5% to about 10% w/w %; v) a ?-globulin fraction of from about 3% to about 20% w/w %; vi) a ?-globulin fraction of from about 5% to about 20% w/w %; vii) a calcium (Ca) concentration of from about 0.1 mmol/L to about 3 mmol/L; viii) a magnesium (Mg) concentration of from about 0.05 mmol/L to about 0.8 mmol/L; ix) an inorganic phosphate (P) concentration of from about 0.1 mmol/L to about 1.5 mmol/L; x) an iron (Fe) concentration of from about 0.001 mmol/L to about 0.