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

Highly Adhesive Antimicrobial Coatings for External Fixation Devices

“…The metallic wires that are used in external fixation were developed in 1909 by Martin Kirschner and are now called Kirshner wires or pins (K-wires) [ 7 ]. A K-wire’s functions include: penetrating and holding bone fragments together, providing an anchor for skeletal traction, and guided cannulated screw placement [ 7 , 8 , 9 ]. In some instances, they are driven into the bone using a power drill and stay inserted until the fracture heals, which is typically 2–4 months [ 7 ].…”

“…Complications associated with this procedure vary from minor to life-threatening and can occur immediately after the implantation [ 10 ]. For example, heat generation and the subsequent temperature rise caused by the friction between the rotating wire and bone can result in thermal osteonecrosis, which, in turn, gives rise to pin loosening and eventual loss of fixation [ 7 , 8 , 9 , 11 ]. Additionally, it can lead to K-wire migration, during which the fixation is lost and the pin deviates from its intended anatomic location [ 12 , 13 ].…”

“…Bending the distal end of the K-wire prevents this migration in most cases, but even bent wires can migrate after breakage, so periodic radiographs should be made until the wire is removed [ 14 ]. A few strategies have been proposed to decrease the heat generation during the drilling, including tip design, drilling technique, and cooling methods [ 7 , 8 , 9 , 11 , 15 , 16 , 17 ]. Hammering, as opposed to rotary drilling, has been one of the more recent trends to reduce the thermal stressing of osteocytes [ 18 ].…”

Comparison of k‐wire insertion using oscillatory and unidirectional drilling modes under constant thrust force

“…The thrust force, mainly reported as resultant force in previously machine‐based studies, is the major haptic feedback for surgeons in surgery and thus a focus of this study. Studies have also been conducted under unidirectional insertion mode to investigate modified K‐wire tip geometries to achieve lower bone temperature compared to commonly used trocar and diamond K‐wire tips 21–24 . The oscillatory drilling mode, introduced by Nichter et al in 1992, 25 oscillates the K‐wire about its longitudinal axis during insertion.…”

“…Studies have also been conducted under unidirectional insertion mode to investigate modified K-wire tip geometries to achieve lower bone temperature compared to commonly used trocar and diamond K-wire tips. [21][22][23][24] The oscillatory drilling mode, introduced by Nichter et al in 1992, 25 oscillates the K-wire about its longitudinal axis during insertion. The oscillatory mode was reported to reduce the bone temperature rise and tissue damage around the drilling site.…”