Overview
Kirschner wires, also known as K-wires, are small metallic wire segments that are used in various medical procedures to hold bone fragments together or to provide an anchor for skeletal traction. They are typically used in surgeries of the upper and lower limbs, fingers, toes, and feet. The size of the Kirschner wire is determined by several factors, including the age and weight of the child, the size and location of the fracture, and the specific indication for use.
Size Information
Kirschner wires are available in various sizes, which typically range from 0.64mm to 3mm in diameter. The most commonly used sizes for children younger than 5-6 years old are 1.6mm, while for older children and adults, the 2.0mm size is more frequently selected. The diameter of the Kirschner wire depends on several factors, including patient age and weight. The table below provides a summary of the recommended sizes for different age groups:
| Age Group | Recommended KirschnerWire Diameter (mm) |
|---|---|
| Children aged < 5-6 years | 1.6mm |
| Children aged 5-6 years | 2.0mm |
| Older children and adults | 2.0mm |
Fracture Location Considerations
The size of the Kirschner wire chosen should be adapted to the specific indication for use. For example, metaphyseal fractures of long bones require at least 1.6mm K-wires, while if only two wires are used, larger diameter wires may be necessary. Fractures of small bones (hand and foot) require 1.0–1.6mm K-wires. The size of the Kirschner wire should be chosen according to the size of the fragment. For example, a fracture of the medial epicondyle of the humerus requires a K-wire of smaller diameter than a fracture of the lateral humeral condyle.
Planning and Entry Point
K-wire insertion usually starts from the free fragment into the main fragment. This allows the K-wire to be used as a joystick for manipulating the free fragment. The entry point of the K-wire should be chosen so that it is as far apart as possible where it crosses the fracture line. This guarantees maximal rotational stability. The planing of the entry point mustCorrelate with the planned direction of the K-wire and the end fixation point in the main fragment. The ideal approach is to introduce the K-wire perpendicular to the fracture plane when possible, but in some cases, this may not be feasible, and compromising mechanical stability should not be an option.
Insertion Techniques
Insertion of K-wires is monitoring by using intermittent image intensification. A small incision or direct puncture with the K-wire is made over the planned entry point. To avoid thermal injury, especially to the physis, K-wires should be inserted by hand or using an oscillating drill. If a standard drill is used, it must be run as slowly as possible to avoid a thermal effect. Additionally, irrigation of the K-wire during drilling with a cooled irrigation fluid
Removal
Removal of K-wires is a matter of judgment by the treating surgeon, based on the age of the child, the pattern of the injury, as well as additional injuries. Depending on the age o
