Does the bone drill bit remain sharp after a collision with the intramedullary pin? a study on isolated canine tibias.

Abstract

BACKGROUND: Blunting of the tip, as well as smoothing and abrasion of the cutting edges, are natural signs of wear observed under magnification after repeated use of bone drill bits. The lack of a standardized surgical protocol for using drill bits in human and veterinary surgery often results in their use beyond the manufacturer’s recommended limits. Drilling with a dull drill bit results in excessive local material degradation, increased surface roughness, and inaccurate hole dimensions. In bone surgery, an additional factor is thermal damage to the bone. Colliding with a metallic object while rotating can cause the cutting edges of the drill bit to become blunt or chipped, or the drill bit to bend or break. This study aimed to analyze damage to bone drill bits resulting from collisions with an intramedullary Kirschner wire. METHODS: The experiment was performed on the left and right isolated tibias of an adult female Boxer dog. Kirschner wires were inserted intramedullary, and holes were drilled in mediolateral and craniocaudal directions to mimic plate-rod osteosynthesis. The drill bits were evaluated for suitability for repeated use based on an examination using a binocular stereomicroscope and digital microscope. RESULTS: One bone drill bit broke. Only 17 / 44 unbroken bone drill bits (39%) could be reused following collision with the Kirschner wire. Twenty-seven drill bits sustained significant damage to their main cutting edges and were deemed unsuitable for reuse. CONCLUSIONS: Contact between the rotating drill bit and the intramedullary implant is undesirable. If this occurs, the drill bit should be examined under a microscope to determine its suitability for further use. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12917-026-05313-1.