Evaluation of wave velocity in bovine meniscus by laser ultrasound technique

Abstract

Laser ultrasound technique is suitable to measure the ultrasound velocity of small samples such as meniscus. In this study, longitudinal wave velocities in bovine meniscus samples were measured using a short pulsed laser. The samples were obtained from the knee joint of bovine femurs and five cubes (3×3×3 mm3) were manually manufactured. The ultrasonic wave generated by the laser was propagated through the samples and the corresponding velocities in the axial, radial, and tangential directions were measured. The obtained velocity range was 2820–3560 m/s. The highest velocities were found in the tangential direction, followed by the velocities in the radial and axial directions, except for the samples extracted from the most posterior part of the meniscus, where the velocities were highest in the radial direction. In order to investigate the anisotropy of the meniscus, the cube samples were processed into octagonal prisms, and the velocities in the directions between tangential and axial directions were measured. The velocities observed in these directions were between the values of the ones in the tangential and the axial directions, showing the uniaxial anisotropy.