POSTER ABSTRACTS - ISAKOS

Materials and methods: This original system was
developed for evaluating the material properties
of articular cartilage by analyzing the reflected
waves by means of wavelet transformation. Using
this system, information on the material and
structural properties of articular cartilage can be
obtained easily and non-invasively. In addition to
intensity (index of stiffness), duration time (index
of surface irregularity) and interval (index of
cartilage thickness) can be assessed
simultaneously. Therefore this system appears to
be useful for evaluating the material and
structural properties of, not only articular
cartilage, but also the meniscus, especially in
vivo.
Five pairs of menisci were obtained from five
knee joints of mature 6-month-old pigs and each
meniscus was divided equally into three sections
to make block-shaped specimens. Both the
femoral and tibial articular surfaces of these
specimens were measured with the ultrasound
system. Three-millimeter and 1-mm-thick discs
with a diameter of 6-mm were harvested from
both articular surfaces of each specimen and
measured in the same way. An unconfined
compression test was also carried out with 1-mmthick
discs harvested from another five pairs of
menisci, and a stress-strain curve was prepared.
Results: There was no statistically significant
difference in the maximum magnitude of the wave
reflected at the articular surface of the meniscus
between the three shapes of specimen. This
indicated that the shape of the specimen did not
influence this index. This index also had a good
correlation with the gradient of the stress-strain
curve at 20-30% strain in unconfined compression
(r=0.61, p