The purpose of this research is to design analogues for periprosthetic fluid, normal synovial fluid, degenerative synovial fluid, and inflammatory synovial fluid. The objective is to obtain initial values for rheological properties that match the analogues. The analogues should Theologically match the natural fluids. The joint after prosthesis implantation is thought to develop its own synovial fluid (Saari et al., 1993). An analogue to periprosthetic fluid is intended to substitute bovine calf serum (BCS) in wear testing of joint prosthesis. An analogue to normal synovial fluid is intended for use in the lubrication of tissue-engineered cartilage. Analogues to pathological synovial fluids are intended for in vitro simulation of joint disorders.

Reference baseline data were obtained by extracting viscosity vs. shear rate curve data from Tanner et al., (2003) and Schurz and Ribitsch, (1987). BCS and hyaluronic acid (HA) solutions were analysed. Polymer solutions of sodium carboxymethyl cellulose (CMC), xanthan, and blends of both CMC and xanthan were prepared;​ viscosity vs. shear rate curves were obtained and compared to the natural fluids using the modified Cross model. The accuracy of fitting the data to the modified Cross model parameters was found to be 20% for η₀, 100% for λ, and 10% for k.

Results indicated that BCS did not rhcologically match periprosthetic fluid nor did HA solutions yield rheological properties that match normal synovial fluid.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. A polymer blend of 0.25% CMC and 0.1% xanthan yielded a rheological match to periprosthetic fluid. A normal synovial fluid analogue was designed with 0.5% xanthan solution. A degenerative synovial fluid analogue was designed using a polymer solution of 0.5% CMC. An inflammatory synovial fluid analogue was designed using a blend of CMC and xanthan at 0.35% total polymer concentration with mass ratio of 3:​1 (CMC:​ xanthan).

Test-retest variability on the periprosthetic fluid analogue and the normal synovial fluid analogue revealed no apparent degradation of structure. It is expected that these fluids could be suitable for wear testing of prosthetic components, and in mechanical stimulation of cartilage respectively.