K Wire (Kirschner Wire) Specification,Uses, Sizes and Surgical Techniques.

Kirschner wires or K wires are metallicwire (stainless steel) sharpened one or both side, are used to hold bonefragments together (pin fixation) or to provide an anchor for skeletaltraction.

K wire (Kirschner wire) is now widely usedin orthopedics and other types of surgery. These wirescan be drilled through the bone to hold the fragments in place. They can beplaced percutaneously (through the skin) or can be buried beneath the skin.

K-wires are often used to stabilize abroken bone and can be removed in the office once the fracture has healed. SomeK-wires are threaded, which helps prevent movement or backing out of the wire,although that can also make them more difficult to remove.

K Wires (KirschnerWires)are available in various Types, lengths and diameters.

Types: Single Trocar, Double Trocar, Fully Threaded

Diameters: 0.8mm, 1mm, 1.2mm, 1.4mm, 1.5mm, 1.6mm, 1.8mm, 2mm.2.2mm, 2.3mm, 2.5mm, 3mm

Lengths: 80mm, 100mm, 125mm, 150mm, 175mm, 200mm, 225mm, 250mm

K Wire (Kirschner Wire) Indications for Use

K Wire (Kirschner Wire) is indicated foruse in the fixation of bone fractures, bone reconstruction, and as guide pinsfor insertion of other implant. The size of the Pin chosen should be adapted tothe specific indication. Surgeon judgement is required to ensure a K Wire(Kirschner Wire) is appropriate for the indication.

K Wires (Kirschner Wires) are indicated foruse in the following conditions:

• K Wires (Kirschner Wires) are used for temporary fixation     during some operations. After definitive fixation they are then removed.     The pins are usually removed four to five weeks post operation.
       

• They can be used for definitive fixation if the fracture     fragments are small. 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.
       

• K Wire (Kirschner 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. In traction of the femur for example, the protruding     ends of the wire are fixed to the legs of a horsehoe shaped frame which     maintains tension in the wire while the crook of the horseshoe is attached     via line and pulleys to weights which maintain the traction.
       

• K Wire (Kirschner Wire) can be used to guide cannulated screws     to a precise location.
       

K Wire (Kirschner Wire) General principles

K Wire (Kirschner Wire) size is chosenaccording to the age of the child and the size of the fragment.

The entry point, together with the correctdirection of the K-wire, is the key to optimal fixation.

For most simple fractures, two,occasionally three, K Wires (Kirschner Wires) give sufficient stabilization ifthe K-wires:

• Are of the correct size (1.6/2.0 mm)
       

• Do not cross each other at the fracture level
       

• Are intraosseous  

K Wire (Kirschner Wire) osteosynthesisusually requires additional plaster cast protection.

Advantages:

• Cheap  

• Universally available  

• Can be inserted by hand (with a T-handle), but also with a     drill provided thermal injury is avoided
  

• Easy to remove  

Disadvantages:

• Not functionally stable  

Size of K Wire (Kirschner Wire)

The following points influence the size ofthe K Wire (Kirschner Wire)

Patient age/weigh

In children younger than 5-6 years, 1.6 mmK Wires (Kirschner Wires) are used for fractures around the shoulder, elbow,knee, and ankle joints.

In children above this age, 2.0 mm K Wires(Kirschner Wires) are usually used.

It is important to consider the weight ofthe patient when choosing the diameter of the K-wire.

Fracture location

Metaphyseal fractures of the long bonesrequire at least 1.6 mm K-wires (Kirschner Wires). If only two wires are used,larger diameter wires may be necessary.

Fractures of small bones (hand and foot)require 1.0 – 1.6 mm K-wire.

Fragment size

The size of the K Wire (Kirschner Wire)should be chosen according to the size of the fragment. For example, a fractureof the medial epicondyle of the humerus requires a K-wire of smaller diameterthan a fracture of the lateral humeral condyle.

K Wire (Kirschner Wire) trajectory

For fractures fixed with two (or three) KWires (Kirschner Wires) from only one side, one size larger K-wires are usedthan for bilateral crossed K-wiring.

For example, for bilateral crossed K-wiringof a supracondylar humeral fracture, 1.6 mm K-wires can be used, whereas forradial divergent wiring of the same fracture, 2.0 mm K-wires are preferable.

K Wire (Kirschner Wire) Planning

K Wire (Kirschner Wire) entry point

K Wires (Kirschner Wires) are, in mostcases, inserted from the free fragment into the main fragment. This allows theK-wire to be used as a joystick for manipulating the free fragment.

The entry points of the K Wires (KirschnerWires) should be chosen so that they are as far apart as possible where theycross the fracture line. This guarantees maximal rotational stability.

The choice of the entry point mustcorrelate with the planned direction of the K-wires and the end fixation pointin the main fragment.

Ideally, if the anatomical site permits,the K Wires (Kirschner Wires) should be introduced as perpendicular as possibleto the fracture plane. In certain sites, this is not achievable and mechanicalstability should not be compromised by obsessive adherence to the aboveprinciple.

K Wire (Kirschner Wire) direction intransverse

The direction of the K Wires (KirschnerWires) should be chosen so that the K-wires are well separated at the fracturelevel.

To achieve this, the length of the fractureline is divided into four equal parts. Ideally, when using two K-wires, thewires should pass approximately through the green areas in the illustration.

Monolateral divergent K Wires (KirschnerWires)

For oblique (>30°) metaphyseal fracturescrossed K Wire (Kirschner Wire) fixation may be very difficult, or impossible,as at least one of the K Wires (Kirschner Wires) will run nearly parallel tothe fracture line.

For oblique fractures, therefore, divergentmonolateral K-wire fixation is more suitable. For this technique, one sizelarger K Wires (Kirschner Wires) should be used than for cross K-wiring.

If lateral divergent K Wire (KirschnerWire) fixation is not possible, for example, due to soft tissue condition or astructure at risk, another stabilization technique should be used (eg, externalfixator or plate).

K Wire (Kirschner Wire) insertion

Stab incision

A small incision or a direct puncture withthe K-wire is made over the planned entry point. An incision is recommended toavoid skin damage, which might cause pin-track infection.

K Wire (Kirschner Wire) insertion

To avoid thermal injury, especially to thephysis, K Wires (Kirschner Wires) should be inserted by hand or using anoscillating drill.

If a standard drill is used, it must be runas slowly as possible to avoid a thermal effect.

Additionally, irrigate the K Wire(Kirschner Wire) during drilling with a cooled irrigation fluid.

If a drill is used, the K Wire (KirschnerWire) is initially inserted manually through the skin incision, onto the chosenbony entry point. While maintaining the correct position of the tip, the drillis attached to the wire.

To prevent bending of the K Wire (KirschnerWire), it can be helpful to insert the K-wire using an appropriate drill sleeve– this steadies the wire, protects the soft tissues, and ensures optimaldirection.

It is helpful to reduce the length of the KWire (Kirschner Wire) protruding from the drill to avoid whipping of the wireand loss of trajectory.

To avoid skidding, the K Wire (KirschnerWire) tip should initially be held as orthogonal as possible to the bonesurface until the tip of the wire has a good purchase.

Once the tip of the K Wire (Kirschner Wire)has obtained a good purchase, the angulation of the K-wire should be correctedaccording to the planned direction of the K-wire.

As soon as increased resistance is felt,check that the tip of the K Wire (Kirschner Wire) is engaged in the far cortexof the main fragment.

The tip of the K-wire should penetrate thewhole depth of the far cortex, but not protrude more than 2–3 mm. This is toavoid neurovascular damage and soft tissue irritation.

The free end of the wire is usually leftprotruding through the skin and is bent through 180°. A sterile dressingprotects the entry wound around the wire.

No more than two attempts should be made toinsert any one wire across a physis. Repeated puncture of the physis bymultiple attempts to insert the wire can result in subsequent growthdisturbance.

K Wire (Kirschner Wire) removal

The timing of K Wire (Kirschner Wire)removal is a matter of judgment by the treating surgeon, based on the age ofthe child, the pattern of the injury, as well as additional injuries.

Depending on the age of the child, fracturehealing has reached the stage where redisplacement is highly unlikely after 3–4weeks and the K-wires can be removed.

K Wire (Kirschner Wire) Contraindications

Contraindications may be qualified ortotal, and need to be taken into consideration when evaluating the prognosis ineach case. The physician’s education, training and professional judgement mustbe relied upon to choose the most appropriate device and treatment. Conditionspresenting an increased risk of failure include:

• Any active or suspected latent infection or marked local     inflammation in or about the affected area.
       

• Compromised vascularity that would inhibit adequate blood     supply to the fracture or the operative site.
       

• Bone stock compromised by disease, infection or prior     implantation that can not provide adequate support and/or fixation of the     devices.
       

• Material sensitivity, documented or suspected.
       

• Obesity. An overweight or obese patient can produce loads on     the implant that can lead to failure of the fixation of the device or to
     
       failure of the device itself.
       

• Patients having inadequate tissue coverage over the operative     site.
       

• Implant utilization that would interfere with anatomical     structures or physiological performance.
       

• Any mental or neuromuscular disorder which would create an     unacceptable risk of fixation failure or complications in postoperative     care.
       

• Other medical or surgical conditions which would preclude the     potential benefit of surgery.
       

• All associated diseases which could endanger the function and     success of the K Wire (Kirschner Wire).
       

Warnings and Precautionary for K Wire(Kirschner Wire)

Before using K Wire (Kirschner Wire), thesurgeon and ancillary staff should study the safety information in theseinstructions, as well as any product-specific information in the productdescription, surgical procedures and/or brochures.

wire is made from medical grade materialsand are designed, constructed and produced with utmost care. These quality wireassure best working results provided they are used in the proper manner.Therefore, the following instructions for use and safety recommendations mustbe observed.

Improper use of wire can lead todamage to the tissue, premature wear, destruction of the instruments andinjury to the operator, patients or other persons.

It is vital for the operating surgeon totake an active role in the medical management of their patients. The surgeonshould thoroughly understand all aspects of the surgical procedure andinstruments including their limitations. Care in appropriate selection andproper use of surgicalinstruments isthe responsibility of the surgeon and the surgical team. Adequate surgicaltraining should be completed before use of implants.

Factors which could impair the success ofthe operation:

• Allergies to implanted materials.
       

• Localized bone tumours.

• Osteoporosis or osteomalacia.
       

• System disease and metabolic disturbances.
       

• Alcohol and drug abuse.

• Physical activities involving excessive shocks, whereby the     implant is exposed to blows and/or excessive loading.
     

• Patients who are mentally unable to understand and comply with     the doctor’s instructions.
       

• Poor general health.

Possible Adverse Effects

The following adverse effects are the mostcommon resulting from implantation:

• Loosening of the wire, which may result from cyclic loading of     the fixation site and/or tissue reaction of the implant.
       

• Early and late infection.
       

• Further bone fracture resulting from unusual stress or weakened     bone substance.
       

• Temporary or chronic neural damage resulting from pressure or     hematomata.
       

• Wound hematomas and delayed wound healing.
       

• Vascular disease including venal thrombosis, pulmonary embolism     and cardiac arrest.
       

• Heterotopic ossification.
       

• Pain and discomfort due to presence of the K Wire (Kirschner     Wire).
       

• Mechanical failure of the implant, including bending, loosening     or breakage.
       

• Migration of implant resulting in injury.
     

Preoperative Planning for K Wire (KirschnerWire)

The operating planning is carried outfollowing a thorough clinical evaluation of the patient, Also, x-rays must betaken to allow a clear indication of the bony anatomy and associateddeformities. At the time of the operation, the corresponding implantationinstruments inaddition to a complete size of K Wire (Kirschner Wire) must be available.

The clinician should discuss with thepatient the possible risks and complications associated with the use ofimplants. It is important to determine pre-operatively whether the patient isallergic to any of the implant materials. Also, the patient needs to beinformed that the performance of the device cannot be guaranteed ascomplications can affect the life expectancy of the device.

K Wire (Kirschner Wire) Precautions

• Confirm functionality of instruments and check for     wear during reprocessing. Replace worn or damaged instruments prior to     use.
       

• It is recommended to use the instruments identified for this     wire.
   

• Handle devices with care and dispose worn bone cutting     instruments in a sharps container.
       

• Always irrigate and apply suction for removal of debris     potentially generated during implantation or removal.
       

K Wire (Kirschner Wire) Warnings

• K Wire (Kirschner Wire) can break during use (when subjected to     excessive forces). While the surgeon must make the final decision on     removal of the broken part based on associated risk in doing so, we     recommend that whenever possible and practical for the individual patient,     the broken part should be removed. Be aware that implants are not as     strong as native bone. Implants subjected to substantial loads may fail.
       

• Instruments, screws and cut plates may have sharp edges or     moving joints that may pinch or tear user’s glove or skin.
       

• Take care to remove all fragments that are not fixated during     the surgery.
     

• While the surgeon must make the final decision on implant     removal, we recommend that whenever possible and practical for the     individual patient, fixation devices should be removed once their service     as an aid to healing is accomplished. wire removal should be followed by     adequate post-operative management to avoid refracture.
       

K Wire (Kirschner Wire) General AdverseEvents

As with all major surgical procedures,risks, side effects and adverse events can occur. While many possible reactionsmay occur, some of the most common include: Problems resulting from anesthesiaand patient positioning (e.g. nausea, vomiting, dental injuries, neurologicalimpairments, etc.), thrombosis, embolism, infection, nerve and/or tooth rootdamage or injury of other critical structures including blood vessels,excessive bleeding, damage to soft tissues incl. swelling, abnormal scarformation, functional impairment of the musculoskeletal system, pain,discomfort or abnormal sensation due to the presence of the device, allergy orhypersensitivity reactions, side effects associated with hardware prominence,loosening, bending, or breakage of the device, mal-union, non-union or delayedunion which may lead to breakage of the K Wire (Kirschner Wire), reoperation.