Article

Articular cartilage of young healthy individuals is dynamic and
responsive to loading behaviors. The purpose of this study was to evaluate the
relationship of cartilage T(1rho) and T(2) relaxation times with loading kinetics
during jumping tasks in healthy young individuals. METHODS: Fourteen healthy
subjects underwent: 1) motion analysis while performing a unilateral hopping task
and bilateral drop jumping task; and 2) quantitative imaging using a 3 Tesla MRI
for T(1rho) and T(2) relaxation time analysis. Three dimensional net joint
moments and angular impulse was calculated using standard inverse dynamics
equations. Average T(1rho) and T(2) relaxation times and medial-lateral ratios
for each were calculated. Multiple regression was used to identify predictors of
cartilage relaxation times. FINDINGS: Average knee flexion moment during hopping
was observed to best predict overall T(1rho) (R(2)=.185) and T(2) (R(2)=.154)
values. Peak knee adduction moment during a drop jump was the best predictor of
the T(1rho) medial-lateral ratio (R(2)=.220). The T(2) medial-lateral ratio was
best predicted by average internal rotation moment during the drop jump
(R(2)=.174). INTERPRETATION: These data suggest that loads across the knee may
affect the biochemistry of the cartilage. In young healthy individuals, higher
flexion moments were associated with decreased T(1rho) and T(2) values,
suggesting a potentially beneficial effect. The medial-to-lateral ratio of
T(1rho) and T(2) times appears to be related to the frontal and transverse plane
joint mechanics. These data offer promising findings of potentially modifiable
parameters associated with cartilage composition.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS