Kirschner wires or K-wires or pins are sterilized

Sterilization (microbiology)

Sterilization is a term referring to any process that eliminates or kills all forms of microbial life, including transmissible agents present on a surface, contained in a fluid, in medication, or in a compound such as biological culture media...

, sharpened, smooth stainless steel

Stainless steel

In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....

 pins. Introduced in 1909 by Martin Kirschner

Martin Kirschner

Martin Kirschner was a German surgeon, born 28 October 1879 in Breslau, died on 30 August 1942 in Heidelberg.Kirschner was the son of Margarethe Kalbeck, sister of Max Kalbeck, and Judge Martin Kirschner , who later served as city councillor of Breslau since 1873 and a member of the city...

, the wires are now widely used in orthopaedics

Orthopedic surgery

Orthopedic surgery or orthopedics is the branch of surgery concerned with conditions involving the musculoskeletal system...

 and other types of medical and veterinary surgery

Veterinarian

A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....

. They come in different sizes and are used to hold bone fragments together (pin fixation) or to provide an anchor for skeletal traction. The pins are often driven into the bone through the skin (percutaneous pin fixation) using a power or hand drill. They also form part of the Ilizarov apparatus

Ilizarov apparatus

The Ilizarov apparatus is named after the orthopedic surgeon Gavriil Abramovich Ilizarov from the Soviet Union, who pioneered the technique. It is used in surgical procedures to lengthen or reshape limb bones; to treat complex and/or open bone fractures; and in cases of infected non-unions of bones...

.

Variations

Threaded K-wires are manufactured. They are used in situations where backing out of the pin is undesirable but they are weaker.

"Denham Pins" are strong stout wires with a threaded portion in the middle. They are used for skeletal traction with the threads engaging the bone.

Indications

• K-wires are used for temporary fixation during some operations. After definitive fixation they are then removed.
• They can be used for definitive fixation if the fracture fragments are small (e.g. wrist fractures
  Distal radius fracture
  A distal radius fracture is a common bone fracture of the radius in the forearm. Because of its proximity to the wrist joint, this injury is often called a wrist fracture...
  
   and hand injuries). In some settings they can be used for intramedullary fixation of bones such as the ulna.
• Tension band wiring is a technique in which the bone fragments are transfixed by K-wires which are then also used as an anchor for a loop of flexible wire. As the loop is tightened the bone fragments are compressed together. Fractures of the kneecap and the olecranon process of the elbow are commonly treated by this method.
• A wire is passed through the skin then transversely through the bone and out the other side of the limb. The wire is then attached to some form of traction so that the pull is applied directly to bone.
• They can be used for temporary immobilization of a joint.

Complications

• Pin tract infection: Because K-wires often pass through the skin into bone they form a potential passage for bacteria
  Bacteria
  Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
  
   from the skin to migrate into the bone and cause an infection
  Osteomyelitis
  Osteomyelitis simply means an infection of the bone or bone marrow...
  
  . In such cases, the area around the pin becomes red and swollen and may start to drain pus. Usually this infection clears up after removal of the pin.
• Breakage: K-wires may bend or break, especially if the fracture does not heal.
• Loss of fixation: Smooth K-wires may back out of the bone losing the fixation. This is especially likely if they pass between two mobile bones.
• Migration of K-wires can occur; instead of backing out the wire can move deeper. K-wires passed across the acromioclavicular (AC) joint in the shoulder have been found to migrate into the chest with the potential to penetrate the major blood vessels, the trachea, lung, or the heart.