Which material is used to test Kerrison rongeurs?

Kerrison rongeurs are surgical instruments used primarily to remove bone, as well as for accessing the epidural space. To test their function and ensure that they open and close properly for precision cutting, an index card serves as a practical test object. The stiffness and thickness of an index card make it an appropriate material to evaluate the sharpness and functionality of the cutting edges of the rongeur, as the instrument should easily cut through the card without excessive effort.

Using other materials, such as a surgical sponge, plastic container, or metal ruler, would not adequately simulate the resistance needed to test the specific action of the rongeurs. A surgical sponge is soft and would not provide the necessary tactile feedback to assess sharpness, while a plastic container or metal ruler doesn't mimic the cutting action required for effective testing. Thus, the index card is the best choice for effectively assessing the operational readiness of Kerrison rongeurs.