A New Device to Detect Early Cartilage Degeneration

Background Currently available arthroscopic techniques do not allow the quantification of cartilage stiffness without direct mechanical indentation or penetration of the tissue. Purpose A novel device, capable of quantifying cartilage stiffness during arthroscopy, is believed to detect degenerated cartilage. Study Design Controlled laboratory study. Methods The stiffness of biological materials was measured arthroscopically without contact between the instrument and the examined object. Object deformation was produced by a flow of sodium chloride and measured optically. Eight ovine femoral condyles and tibial plateaus were tested in a native and degenerated (0.1% trypsin solution) state. Cartilage stiffness was nondestructively determined by using the new device and by indentation methods. In addition, a standard probe was measured by 5 independent users. Results The trypsin caused cartilage degeneration and consequently stiffness reduction, measured at 30.8% by the new device and 33.0% by indentation. A good correlation (r = 0.69) between the new device and the standard indentation procedure was observed. Intraindividual and interindividual variability of the new device were low (<10%). Conclusions The developed device has demonstrated the ability to quantify the mechanical quality of cartilage by means of mechanical stiffness measurements. Clinical Relevance The findings suggest that this device has the capability to detect cartilage degeneration at an early stage.