Ability of ultrasound backscattering to predict mechanical properties of bovine trabecular bone.

Ultrasound (US) backscatter measurements have been proposed for the quantitative evaluation of bone quality. In this study, we explored the ability of broadband US backscatter (BUB) and integrated reflection coefficient (IRC) to predict density and mechanical properties of trabecular bone, as compared to normalized broadband US attenuation (nBUA) and speed of sound (SOS). These acoustic parameters were measured in 41 in vitro samples of bovine trabecular bone and correlated with a number of mechanical parameters and with volumetric bone mineral density (BMDvol).

Ultrasonic quantitation of superficial degradation of articular cartilage.

Ultrasound (US) has been suggested as a means for the quantitative detection of early osteoarthrotic changes in articular cartilage. In this study, the ability of quantitative US 2-D imaging (20 MHz) to reveal superficial changes in bovine articular cartilage after mechanical or enzymatic degradation was investigated in vitro. Mechanical degradation was induced by grinding samples against an emery paper with the grain size of 250 microm, 106 microm, 45 microm or 23 microm.

Ultrasound attenuation in normal and spontaneously degenerated articular cartilage.

High-frequency ultrasound (US) measurements may provide means for the quantification of articular cartilage quality. Bovine patellar cartilage samples (n = 32) at various degenerative stages were studied using US attenuation measurements in the 5- to 9-MHz frequency range. The results were compared with the histologic, biochemical and mechanical parameters obtained for the same samples, to identify which structural or functional factors could be related to the attenuation and its variations.

Ultrasound indentation of bovine knee articular cartilage in situ.

We have earlier developed a handheld ultrasound indentation instrument for the diagnosis of articular cartilage degeneration. In ultrasound indentation, cartilage is compressed with the ultrasound transducer. Tissue thickness and deformation are calculated from the A-mode ultrasound signal and the stress applied is registered with the strain gauges.

Mechano-acoustic diagnosis of cartilage degeneration and repair.

Background: The combined use of high-frequency ultrasound and mechanical indentation has been suggested for the evaluation of cartilage integrity. In this study, we investigated the usefulness of high-resolution B-mode ultrasound imaging and quantitative mechanical measurements for the diagnosis of cartilage degeneration and for monitoring tissue-healing after autologous chondrocyte transplantation.

Methods: In the first study, osteochondral samples (n = 32) were obtained from the lateral facet of a bovine patella, and the samples were visually classified as intact (n = 13) or degenerated (n = 19) and were graded with use of the Mankin scoring system.

Real-time ultrasound analysis of articular cartilage degradation in vitro.

The sensitivity of the reflection coefficient, attenuation and velocity to the enzymatic degradation of bovine patellar cartilage was evaluated in real-time with high-frequency ultrasound (US) (29.4 MHz). These parameters were estimated from the radiofrequency (RF) signal, which was recorded at 5-min intervals during the digestion of the tissue by collagenase or by trypsin.