Ul
trasound (US) has been sugges
ted as a means for
the quan
ti
ta
tive de
tec
tion of early os
teoar
thro
tic changes in ar
ticular car
tilage. In
this s
tudy,
the abili
ty of quan
ti
ta
tive US 2-D imaging (20 MHz)
to reveal superficial changes in bovine ar
ticular car
tilage af
ter mechanical or enzyma
tic degrada
tion was inves
tiga
ted
in vitro. Mechanical degrada
tion was induced by grinding samples agains
t an emery paper wi
th
the grain size of 250 μm, 106 μm, 45 μm or 23 μm. For enzyma
tic degrada
tion, samples were diges
ted wi
th collagenase,
trypsin or chondroi
tinase ABC. Varia
tions of
the US reflec
tion coefficien
t induced by
the degrada
tion were inves
tiga
ted. Fur
thermore,
two novel parame
ters,
the US roughness index (
URI) and
the spa
tial varia
tion of
the US reflec
tion coefficien
t (
SVR), were es
tablished
to quan
ti
ta
te
the in
tegri
ty of
the car
tilage surface. S
ta
tis
tically significan
t decreases (
p &l
t; 0.05) in US reflec
tion coefficien
t were observed af
ter mechanical degrada
tions or enzyma
tic diges
tion wi
th collagenase. Increases (
p &l
t; 0.05) in
URI were also revealed af
ter
these
trea
tmen
ts. We conclude
tha
t quan
ti
ta
tive US imaging may be used
to de
tec
t collagen disrup
tion and increased roughness in
the ar
ticular surface. These s
truc
tural damages are
typical of early os
teoar
throsis. (E-mail:
ttp://mailto:saarakka@hytti.uku.fi"">mailto:saarakka@hytti.uku.fi)