Fontenelle C R C, Mannarino P, Ribeiro F B D O, Milito M A, Carvalho A C P, Menegaldo L L, Oliveira L F
Department of Orthopaedic Surgery, UFRJ, Clementino Fraga Filho University Hospital, Rio de Janeiro, Brazil.
UFRJ, Biomedical Engineering Program, LAMFE, Rio de Janeiro, Brazil.
Clin Physiol Funct Imaging. 2018 Feb 7. doi: 10.1111/cpf.12506.
Shear modulus (μ) is directly correlated to the tissue stiffness and can predict the tendon ultimate force to failure. With the knee extended 0° (K0), semitendinosus tendon (ST) is tensioned while patellar tendon (PT) is relaxed. At 80 , knee flexion (K80) tendons present an opposite stress pattern; however, the relation between ST and PT μ in both situations was not studied yet.
We accessed the μ of the ST and PT at 0 and 80 knee flexion by supersonic shear wave imaging (SSI) elastography from 18 healthy males. Relative μ indexes were calculated for relaxed and tensioned conditions.
The average μ for ST was μ = 197·62 ± 31·93 kPa and μ = 77·76 ± 30·08. For TP, values were μ = 23·45 ± 5·89 and μ = 113·92 ± 57·23 kPa. Relative μ indexes were calculated for relaxed (IR = μ /μ ) and tensioned conditions (IT = μ /μ ). The relative μ indexes were IR = 3·63 ± 1·50 and IT = 2·00 ± 0·96 (P<0·05).
Semitendinosus tendon μ was significantly higher than PT μ in both tensioned and relaxed positions. This can predict a higher ultimate force to failure and a less elastic behaviour in ST grafts when compared to PT grafts. This new parameter could aid physicians in graft choice previous to anterior cruciate ligament reconstruction.
剪切模量（μ）与组织硬度直接相关，并且可以预测肌腱的极限破坏力。在膝关节伸展0°（K0）时，半腱肌肌腱（ST）处于紧张状态，而髌腱（PT）处于松弛状态。在膝关节屈曲80°（K80）时，肌腱呈现相反的应力模式；然而，尚未研究这两种情况下ST和PT的μ之间的关系。
我们通过超声剪切波成像（SSI）弹性成像技术，对18名健康男性在膝关节屈曲0°和80°时的ST和PT的μ进行了测量。计算了松弛和紧张状态下的相对μ指数。
ST的平均μ值为μ = 197.62±31.93 kPa和μ = 77.76±30.08。对于PT，其值为μ = 23.45±5.89和μ = 113.92±57.23 kPa。计算了松弛状态（IR = μ /μ ）和紧张状态（IT = μ /μ ）下的相对μ指数。相对μ指数分别为IR = 3.63±1.50和IT = 2.00±0.96（P<0.05）。
在紧张和松弛状态下，半腱肌肌腱的μ均显著高于髌腱的μ。这可以预测与髌腱移植物相比，半腱肌肌腱移植物具有更高的极限破坏力和更低的弹性行为。这一新参数可在进行前交叉韧带重建之前帮助医生选择移植物。
