Suydam Stephen M, Cortes Daniel H, Axe Michael J, Snyder-Mackler Lynn, Buchanan Thomas S
Delaware Rehabilitation Institute, University of Delaware, Newark, Delaware, USA.
Department of Mechanical and Nuclear Engineering, Pennsylvania State University, State College, Pennsylvania, USA.
Orthop J Sports Med. 2017 Jun 27;5(6):2325967117712944. doi: 10.1177/2325967117712944. eCollection 2017 Jun.
Semitendinosus/gracilis (STG) tendon autograft has been used effectively for restoring knee stability after anterior cruciate ligament (ACL) rupture. Though ACL reconstruction with STG autograft is an effective surgical technique for return to sports, short-term hamstring strength asymmetries exist after surgery. Although imaging evidence has demonstrated regrowth and reorganization of the semitendinosus (ST) tendon, no studies show whether the regrowth is associated with residual muscle function. Continuous shear wave elastography (cSWE) using an external actuator and high-frame rate ultrasound is a promising technique for evaluating the mechanical properties of regrown tendons in vivo.
To demonstrate recovery of the mechanical properties of the hamstring tendons after ACL reconstruction using an STG tendon autograft.
Case series; Level of evidence, 4.
Thirteen patients underwent an STG autograft reconstruction after ACL rupture. Regrowth of the ST tendon was confirmed via b-mode ultrasound between 6 and 24 months postreconstruction. The shear elastic () and viscosity moduli () of the ST tendons were ascertained through cSWE using an external actuator and high-frame rate ultrasound.
Significant differences in both shear elastic (129.4 vs 73.0 kPa) and viscous moduli (192.6 vs 114.3 Pa·s) existed bilaterally for uninvolved and involved limbs, respectively. Additionally, a positive correlation between time postoperative and shear elasticity was observed ( = 0.60). More than 12 months were required for patients to regain a large percentage of the tendon's mechanical properties compared with the contralateral side (, 80.6% at >12 months vs 39.9%; , 78.7% at >12 months vs 46.0%).
The imaging and elastography data demonstrate tendon regrowth and recovery of functional biomechanical properties with time. The elastic modulus of the recovered tendon indicates the ability to transmit muscle force across the joint and recovery of semitendinosus function after its use for an ACL graft.
半腱肌/股薄肌（STG）肌腱自体移植已被有效地用于恢复前交叉韧带（ACL）断裂后膝关节的稳定性。尽管采用STG肌腱自体移植进行ACL重建是一种使患者恢复运动的有效手术技术，但术后短期内腘绳肌力量存在不对称。虽然影像学证据已证明半腱肌（ST）肌腱的再生和重塑，但尚无研究表明这种再生是否与残余肌肉功能相关。使用外部驱动器和高帧率超声的连续剪切波弹性成像（cSWE）是一种在体内评估再生肌腱力学性能的有前景的技术。
证明采用STG肌腱自体移植进行ACL重建后腘绳肌腱力学性能的恢复。
病例系列；证据等级，4级。
13例患者在ACL断裂后接受了STG自体移植重建。通过B超在重建后6至24个月确认ST肌腱的再生。使用外部驱动器和高帧率超声通过cSWE确定ST肌腱的剪切弹性（）和粘性模量（）。
未受累侧和受累侧的剪切弹性（分别为129.4与73.0 kPa）和粘性模量（分别为192.6与114.3 Pa·s）均存在显著差异。此外，观察到术后时间与剪切弹性之间呈正相关（= 0.60）。与对侧相比，患者需要超过12个月才能恢复大部分肌腱的力学性能（，>12个月时为80.6%，而39.9%；，>12个月时为78.7%，而46.0%）。
影像学和弹性成像数据表明肌腱随时间再生并恢复功能生物力学性能。恢复肌腱的弹性模量表明其具有跨关节传递肌肉力量的能力以及在用于ACL移植后半腱肌功能的恢复。
