Relationship of surface damage appearance and volumetric wear in retrieved TKR polyethylene liners.

Recently developed techniques have enabled volume loss measurements on surgically retrieved total knee replacements (TKR). However, it is not well understood how volume loss relates to polyethylene surface damage appearance. Sixty-four fixed bearing cruciate retaining components retrieved from revision and postmortem surgeries were analyzed for penetration and volume loss on the topside articular surface. An autonomous reconstruction method was used to approximate the original unworn surfaces. Surface damage patterns were also mapped using a video microscope, and each pattern's contribution to volume loss was calculated. With consideration for creep, a total wear rate of 12.9 ± 5.97 mm3 /year was found for the population. The penetration rate was 0.035 ± 0.017 mm/year medially and 0.034 ± 0.011 mm/year laterally, of which the location on the plateau varied greatly. Although striated patterns contributed to most to volume loss, damage patterns generally were only moderate predictors of material volume loss.