Hollow Notched K‐Wires for Bone Drilling With Through‐Tool Cooling

Abstract

Kirschner wire (K‐wire) is a common tool in clinical orthopedic surgery for bone fracture fixation. A significant amount of heat is generated in bone drilling using K‐wires, causing bone thermal necrosis and osteonecrosis. To minimize the temperature rise, a hollow notched K‐wire in a modified surgical hand drill with through‐tool cooling was developed to study the bone temperature, debris evacuation, and material removal rate. The hollow notched K‐wire was fabricated by grinding and micro‐milling on a stainless steel tube. Bone drilling tests were conducted to evaluate its performance against the solid K‐wires. Results showed that compared with solid K‐wires, hollow notched K‐wire drilling without cooling reduced the peak bone temperature rise, thrust force, and torque by 42%, 59%, and 62% correspondingly. The through‐tool compressed air reduced the peak bone temperature rise by 48% with the forced air convection and better debris evacuation. The through‐tool water cooling decreased the bone temperature by only 26% due to accumulation and blockage of bone debris in the groove and channel. This study demonstrated the benefit of using the hollow notched K‐wire with through‐tool compressed air to prevent the bone thermal necrosis. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2297–2306, 2019