In ultrasonic devices, what is the function of the passive jaw?

In ultrasonic devices, what is the function of the passive jaw?

• A. To aspirate tissue
• B. To cut tissue
• C. To trap tissue against the active blade as a backstop
• D. To deliver irrigation

Answer: (C)

The passive jaw acts as the grasper and backstop. It grabs and compresses tissue so it sits firmly against the vibrating active blade, allowing the ultrasonic energy to cut and coagulate efficiently. This stable tissue apposition reduces slippage and helps protect nearby structures during transection. It does not perform suction, cutting, or irrigation—those functions come from other parts of the instrument or separate devices.

The passive jaw acts as the grasper and backstop. It grabs and compresses tissue so it sits firmly against the vibrating active blade, allowing the ultrasonic energy to cut and coagulate efficiently. This stable tissue apposition reduces slippage and helps protect nearby structures during transection. It does not perform suction, cutting, or irrigation—those functions come from other parts of the instrument or separate devices.