Biotribology: articular cartilage friction, wear, and lubrication

This study developed, explored, and refined techniques for the in vitro study of cartilage-on-cartilage friction, deformation, and wear. Preliminary results of in vitro cartilage-on- cartilage experiments with emphasis on wear and biochemistry are presented. Cartilage-bone specimens were obtained from the stifle joints of steers from a separate controlled study. The load, sliding speed, and traverse of the lower specimens were held constant as lubricant and test length were varied. Lubricants tested consisted of a phosphate buffered saline solution, bovine serum, and bovine synovial fluid.

Synovial fluid as a lubricant produced the least amount of damage to the cartilage. Serum produced more wear and damage than synovial fluid, but less than buffered saline (which produced the most damage). Three-hour tests produced more wear than one-hour tests, with severe damage to the lower plug in several of the three-hour tests.

Analysis of the results was possible through: data acquisition of normal load, tangential load, and LVDT displacement; photomacrographs; ESEM and SEM surface studies; stained cross-sectional slides of cartilage; and hydroxyproline analysis of cartilage wear.

Detailed procedures and discussion of results are presented along with recommended changes for future biotribology research.