K wires (Kirschner wires) are a type of stabilization wire/pin used in orthopaedic surgery. They are pointed stainless steel wires that can be used in multiple roles during internal fixation:
- as a temporary measure before more definitive fixation
- thin wires are especially useful for smaller bones (e.g. hands, paediatrics)
- in combination with plates and screws for complex fractures
- for fixation in patients with poor bone quality (lag screws may not have much purchase)
Steinmann pins (or "intramedullary pins") are a similar type of fixation wire/pin. In early orthopaedics the terms for the wires were sometimes used synonymously. Today, a Steinmann pin usually refers to a wire thicker than the K-wire.
- "wire": 0.9-1.5 mm
- "pin": 1.5-6.5 mm
K-wires used to be only inserted with open pre-drilling (in the 1920s), but the infection rate prompted development of a percutaneous approach (now with a pistol-grip wire driver). Pin-track infections are much less common than they used to be.
Another disadvantage of K-wire placement is the potential for migration, which can be especially problematic if the wire/pin migrates into the thorax or the abdomen/pelvis from an adjacent fracture fixation (e.g. from a sacral fracture into the pelvis). Bending the wire or use of threaded wires are thought to decrease the likelihood of migration.
History and etymology
The original Steinmann nail was introduced by Dr Fritz Steinmann in 1907. The original Kirschner wire was introduced in 1909 by Dr Martin Kirschner (1879-1942). Both wires/pins were at first used for traction and only began to be used for fixation in the 1930s.
- 1. Canale ST, Beaty JH. Campbell's Operative Orthopaedics: Expert Consult Premium Edition - Enhanced Online Features. Mosby. ISBN:B00A9LS8TA. Read it at Google Books - Find it at Amazon
- 2. Franssen BB, Schuurman AH, Van der Molen AM et-al. One century of Kirschner wires and Kirschner wire insertion techniques: a historical review. Acta Orthop Belg. 2010;76 (1): 1-6. Pubmed citation