A Pilot Feasibility Study for Ultrasound Evaluation of Living Human Wrist Cartilage: Site-Specific Differences in Acoustic Properties

Abstract

The field of cartilage repair has changed dramatically in the past decade but has not answered the question of how to treat an articular cartilage lesion in the wrist. Indeed, the characteristics of wrist articular cartilage, such as cartilage thickness, hardness, and smoothness, have not been clarified. The purpose of this study was to evaluate and quantify the acoustic properties of wrist articular cartilage quantitatively using a new acoustic probe under arthroscopic observation. We evaluated 10 consecutive patients (9 men, 1 woman) who were examined or treated arthroscopically. The mean age at evaluation was 27 years. In total, 468 points of wrist articular cartilage were investigated using the ultrasonic probe, and the data were transformed into a wavelet map by wavelet transformation. Two parameters, maximum magnitude and echo duration, which are indices of articular cartilage stiffness and macroscopic surface roughness, respectively, were used to evaluate the acoustic properties of wrist cartilage. The distribution pattern of the acoustic properties was similar to that of previous results for the ankle joint. The mean maximum magnitude and echo duration were 3.41 +/- 1.50 (range, 0.89-7.53) and 1.33 mus +/- 0.30 (range, 0.51-2.17 mus), respectively. For the scaphoid fossa, the maximum magnitude of the radial side was significantly lower than that of the ulnar side, and the echo duration of the radial side was significantly longer than that of the ulnar side. A new measurement system using an acoustic probe made it possible to perform a quantitative analysis of wrist articular cartilage, similar to the case for knee and ankle articular cartilage. In addition, site-specific differences in the acoustic properties of the distal radial cartilage were detected in living human wrist cartilage.