Objective: To assess the bio-mechanical properties of paraspinal muscles in adolescent idiopathic scoliosis (AIS). Methods: The MyotonPro® device and shear wave elasticity imaging(SWEI) technique were applied to detect the paraspinal muscle tone (F), stiffness (S), relaxation time (R), Deborah number (C) and elasticity (D) of paravertebral muscles on the concave side and convex side of scoliosis curvature at several points: apex of the curve (a), upper (b) and lower (c) limits of the curve in 23 cases of AIS treated from October to December 2017 in Beijing Chaoyang Hospital.Cobb angle of the main curve was measured on the standing anteroposterior whole spine radiograph.Pearson correlation analysis was applied to detect the relation between the bio-mechanical properties and Cobb angle of the main curve. Results: A total of 23 AIS patients [3 males and 20 females, mean age was (15±4) years] were assessed in this study.The mean Cobb angle was (66±33) degrees.The MyotonPro® data showed that the muscle tone on the concave side were all significantly greater than those on the convex side [a: (18.9±2.2) Hz vs (17.4±1.6) Hz, t=4.435, P<0.05; b: (18.2±2.0) Hz vs (16.7±1.7) Hz, t=4.183, P<0.05; c: (18.0±2.3) Hz vs (16.8±1.7) Hz, t=4.520, P<0.05]. The muscle stiffness on the concave side were all significantly greater than those on the convex side at the three points (t=1.974, 2.048, 1.749, all P<0.05). The relaxation time were all longer on the convex side (t=-3.422, -2.713, -2.380, all P<0.05). The Deborah number were greater on the convex side at a and b points (t=-2.939, -2.466, both P<0.05). No significant difference in elasticity was found between the muscles of the two sides.The SWEI results also indicated that the elasticity of the paraspinal muscles of the two sides were similar.The Pearson correlation analysis showed that stiffness on the concave side was moderate positively correlated with Cobb angle of the main curve (r=0.582, P<0.05). Deborah number on the two sides and relaxation time on the concave were moderate negatively correlated with Cobb angle of the main curve (r=-0.632, -0.432, -0.611, all P<0.05). Conclusions: The bio-mechanical properties of paraspinal muscles in AIS are different significantly between the concave and convex side and affected by the severity of scoliosis.
目的： 评估青少年特发性脊柱侧凸患者(AIS)主弯曲椎旁肌肉生物力学属性。 方法： 对在2017年10至12月于北京朝阳医院就诊的AIS患者应用MyotonPro®肌肉检测技术和超声弹性剪切成像(SWEI)技术评估其主弯曲两侧椎旁肌肉张力(F)、硬度(S)、机械压力释放时间(R)、德博拉数(C)和弹性值(D)。测量点选择为主弯曲顶点(a)、主弯上端(b)、下端(c)水平棘突旁开2 cm，凹侧与凸侧共3对(6个)测量点。在站立位脊柱全长正位X线片上测量患者主弯曲Cobb角。分析AIS患者主弯两侧椎旁肌肉生物力学性能的差异。应用Pearson相关性分析检验生物力学属性与脊柱侧凸Cobb角之间的相关性。 结果： 本研究共纳入23例AIS患者，男3例，女20例，平均年龄(15±4)岁(10～20岁)。患者主弯Cobb角为66°±33°。MyotonPro®肌肉检测仪测量结果显示主弯凹侧各点椎旁肌肌张力较凸侧高，差异有统计学意义[a：(18.9±2.2) Hz比(17.4±1.6) Hz，t＝4.435，P<0.05；b：(18.2±2.0) Hz比(16.7±1.7) Hz，t＝4.183，P<0.05；c：(18.0±2.3) Hz比(16.8±1.7) Hz，t＝4.520，P<0.05]。凹侧各点肌肉硬度较凸侧高，差异均有统计学意义(t＝1.974、2.048、1.749，均P<0.05)。凸侧椎旁肌机械压力释放时间较凹侧长，差异均有统计学意义(t＝－3.422、－2.713、－2.380，均P<0.05)。在a和b点，凸侧椎旁肌德博拉数较凹侧大，差异均有统计学意义(t＝－2.939、－2.466，均P<0.05)。MyotonPro®和SWEI技术检测数据均显示双侧椎旁肌的弹性值差异无统计学意义。Pearson相关性分析显示，在顶椎水平凹侧椎旁肌硬度与主弯Cobb角大小呈中等正相关(r＝0.582，P<0.05)，双侧椎旁肌的德博拉数、凹侧椎旁肌机械压力释放时间与主弯Cobb角大小呈中等负相关(r＝－0.632、－0.432、－0.611，均P<0.05)。 结论： AIS患者主弯两侧椎旁肌生物力学属性存在差异，且椎旁肌生物力学特点与主弯严重程度相关。.
Keywords: Adolescent idiopathic scoliosis; Biomechanics; Paraspinal muscles.