tetrad scar

例句：

1. 1.The patient had a tetrad scar on his left leg.
   病人左腿上有一个四元组疤痕。
2. 2. This surgery was complicated by the patient's tetrad scar.
   这次手术因为患者的四元组疤痕而变得复杂。
3. 3. The doctor examined the patient's tetrad scar and found it to be healing well.
   医生检查了患者的四元组疤痕，发现它正在良好愈合。