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.

In vivo telemetric determination of shear and axial loads on a regenerative cartilage scaffold following ligament disruption

“…This foam simulated the mechanical properties of trabecular bone . Testing was performed on a servo‐hydraulic materials testing system (MTS Corp, Minneapolis, MI) and a silicone layer was placed between the scaffold and loader during axial and shear calibration to uniformly distribute the load over the scaffold . Scaffolds were loaded at 100 N/s up to the peak load of 180 N to simulate expected axial physiological loads and load rates.…”

Determination of joint loads using new sensate scaffolds for regenerating large cartilage defects in the knee

“…The overall goal of this work was to develop an approach to extend the success of earlier studies [19][20][21][22]32 to the treatment of large defects. One specific aim of this study was to create a polymeric "sensate" medial condyle replacement scaffold to anchor autologous ASCs to regenerate cartilage on the medial condyle.…”

“…One specific aim of this study was to create a polymeric "sensate" medial condyle replacement scaffold to anchor autologous ASCs to regenerate cartilage on the medial condyle. Recently, preliminary studies with adult pluripotent stromal cells (ASCs) have demonstrated cartilage regeneration is possible in some osteochondral defects 19,32 and this has led to the potential of growing complete cartilage surfaces on scaffolds.…”