Load measurement accuracy from sensate scaffolds with and without a cartilage surface

ABSTRACT The use of "sensate" scaffolds covered with tissue-engineered cartilage has emerged as a possible treatment option for focal articular cartilage defects. The ability to monitor joint loading provides several benefits that can be useful in both clinical and research situations. Previous studies have shown that these scaffolds can accurately monitor in vivo joint loading during various activities. However, the effect that an articular cartilage layer or soft tissue overgrowth has on scaffold sensitivity has not been tested. Eight scaffolds were tested with cartilage samples taken from four hounds. Three strain gauges were attached to each scaffold and a servo hydraulics system was used to test sensitivity while the scaffold was in contact with cartilage, metal, or silicone surfaces. Strain gauge sensitivity was calculated from load and strain measurements collected during testing. There was no significant difference between the mean strain gauge sensitivities when the scaffolds were in contact with the different surfaces: cartilage 30.9 +/- 16.2 muepsilon/N, metal 31.8 +/- 18.6 muepsilon/N, and silicone 30.6 +/- 12.3 muepsilon/N. These results indicate that "sensate" scaffolds can be calibrated and used to monitor load with the presence of an articular cartilage layer.