Geister K-Rex rongeurs

The Geister K-Rex rongeurs are manually operated surgical instruments made of stainless steel with a TiAIN coating, designed for cutting or biting bone during neurosurgical procedures involving the skull or spinal column. They are reusable, non-sterile, and available in multiple bite sizes (1–6 mm) and lengths (180–280 mm).

The K-Rex rongeurs feature bite sizes of 1–6 mm, shaft lengths of 180–280 mm, jaw opening of 12 mm, cutting angles of 40° and 90° up, and are available with regular or thin footplates. They are constructed from stainless steel (420, 303, 301 per ASTM F-899) with TiAIN surface coating, and are detachable with an ejector mechanism.

Biocompatibility testing per ISO 10993 (cytotoxicity, sensitization, intracutaneous reactivity, acute systemic toxicity, blood interactions, hemolysis, pyrogenicity); reprocessing and sterilization validation per ANSI/AAMI ST98:2022, ISO 17665, and ISO 17664; and cutting performance testing via 10,000-cycle cutting test.

The Geister K-Rex rongeurs share the same intended use (bone cutting during skull and spinal surgery) and similar design, materials, and performance characteristics as the predicate devices (CERAMO KERRISION and SQ.line KERRISONS). Minor differences in jaw sizes, angles, and shaft lengths do not raise new safety or effectiveness questions because the non-clinical performance data (biocompatibility, reprocessing validation, and cutting performance testing) demonstrate equivalent functionality, and these devices have been on the market for many years with proven safety and efficacy.