膝側副靱帯のストレイン超音波エラストグラフィによる生体内剛性評価

抄録

To determine the stiffness of the medial (MCL) and lateral (LCL) collateral ligaments in varying knee flexion angles. Strain ultrasound elastography with an acoustic coupler as the reference was applied to obtain relative stiffness of the proximal, middle, distal portions of the superficial MCL (sMCL) and LCL, and meniscofemoral and meniscotibial portions of the deep MCL (dMCL) in 10 healthy males while placing the knee in different flexion angles. The relative stiffness of the ligaments was defined using strain ratio (SR); strain develops in the target tissue to that in the reference. Reliability of the SR values were tested using Intraclass correlation coefficient (ICC). The intra ICC (1, 3) and interrater ICC (2, 3) values for the SR measurements were good (0.6–0.9) for all the ligament portions. The relative stiffness was highest in 0°, and it was decreased when increasing the knee flexion in the MCL. However, LCL have shown a fluctuating stiffness behavior through the flexion pathway. Strain ultrasound elastography is a reliable and feasible tool in routine clinical practice to monitor stiffness of the collateral ligaments. The ligament stiffness decreased from knee extension to flexion.