Quantitative measurement of muscle atropy after ACL reconstruction

(1)利用磁共振成像(MRI)对髂胫束重建前交叉韧带后股四头肌萎缩、突出的情况进行定量测量。对11名竞技水平运动员进行了调查。在MRI的15个轴位切片上，测量股四头肌和股四头肌各部分的肌肉体积。股内侧肌体积较健侧减少8%。股四头肌的空间位置较健侧向外旋转约40ﾟ。股外侧旋转量最大，但股内侧肌和中间肌也表现出一定的过度外旋倾向。在60度/秒和180度/秒的伸直角度下，手术侧的峰值扭矩分别比对照侧下降了15%和9%。(2)用同样的MRI技术对重建前交叉韧带后的股四头肌和腿肌肌进行了定量测量。33名竞技或娱乐水平的运动员接受了半腱肌腱和股薄肌重建前交叉韧带，术后1年以上。股四头肌、股四头肌、摘除肌腱部分后，半腱肌和股薄肌仍保留对照侧的60%和71%的体积，并在标记快照时显示肌肉收缩。拔除的肌腱没有再生。其中6例可见半膜肌和股二头肌轻度肥大。股部肌肉的这些形态变化与膝关节屈伸最大力矩略有关系。

(1) Quantitative measurement of the quadriceps atrophy and herniation after the ACL reconstruction using the iliotibial tract were performed with the magnetic resonance image (MRI). 11 competitive level athletes were investigated. From the 15 axial slices of the MRI,muscle volume of all components of qurdriceps femoris and hamstrings were measured. The muscle volume of the vastus medialis showed 8% decrease comparing to the normal side. The spatial position of the quadriceps femoris rotated about 40ﾟ externaly comparing to the normal side. Though the largest external rotation occured at vastus lateralis, vastus medialis and intermedius also showed certain tendency of the excessive external rotation. At 60 and 180 deg/sec leg extension of the operated side showed 15% and 9% decrease of the peak torque in comparison with the control side.(2) Quantitative volume measurements of quadriceps femoris and hamstrings after ACL reconstruction were performed with the same MRI technique. 33 competitive or recreational level athletes who underwent ACL reconstruction with semitendinosus and gracilis tendons were investigated more than 1 year after the operatio. The muscle volume of quadriceps femoris and hamstrings showed 5-9% decrease in comparison with the control side. Though the tendinous portions were extirpated, the semitendinosus and gracilis muscles still preserved 60% and 71% of the control side volume, and exhibited muscle contraction at the Tagging Snapshot. There was no regeneration of the extirpated tendons. Slight hypertrophy of semimembranosus and biceps femoris muscle were observed in ha f of the cases. These morphological changes of thigh muscles were slightly related to the peak torque of knee extension and flexion.