An external fixator is a holding device used for the therapy of injured parts of the body. The treatment method counts as osteosynthesis.
What is external fixator?
External fixator is a holding system that is used to immobilize bone fractures. External fixator is a support system used to immobilize bone fractures. In particular, complicated fractures associated with open wounds are treated with this osteosynthesis procedure. The term external fixator comes from the French and means “external fixator”. An external fixator is composed of elongated screws and a rigid frame. The doctor places this outside the body and attaches it to the affected bone using screws. The bone fragments resulting from the fracture can be stabilized in this way. In addition, they cannot move against each other. Various procedures are used in osteosynthesis to restore fractured bones. These include the insertion of wires, screws and plates made of metal. However, these materials are not always suitable for open fractures because they further increase the high risk of infection. For example, there is a risk that the germs will remain in the body, causing the infection to spread and worsen. In contrast, the use of an external fixator, which can stabilize the bone fragments until the infection heals, is considered more appropriate.
Function, effect, and goals
External fixators are most commonly used in trauma surgery for the initial treatment of bone fractures such as comminuted fractures. Typical indications include pronounced open bone fractures, a double fracture on the same bone, closed bone fractures in which there is severe damage to the soft tissues, and infections caused by bone fractures. Other areas of application are polytrauma, i.e. multiple life-threatening injuries that are present at the same time, and pseudarthrosis. This is a so-called false joint. It forms after insufficient bone healing. Sometimes, however, the external fixator is also used to intentionally stiffen joints. Furthermore, the special apparatus can be used for segmental transport. The Ilisarov method, which originated from the Soviet surgeon Gavril Ilisarov, who lengthened bones with an external ring fixator, is most commonly used. By cutting the bone at a specific point, an artificial fracture is created. Then both parts of the bone are fixed to an appliance, which progressively widens the gap of the fracture site. As a result of the bone being pulled apart, its growth occurs. Over the years, this procedure has been further improved. Also among the applications of the external fixator are fractures of the cervical spine and various deformities in which it is used for callus distraction. These mostly involve different leg lengths. Before an external fixator is applied, the patient receives general anesthesia. How the patient is positioned depends on his or her injury. For example, in the case of a wrist fracture, the doctor angles the patient’s arm slightly and elevates it slightly. During the procedure, the surgeon constantly checks the patient’s wrist via X-rays. In this way, it can be determined whether the bone fragments are also brought into the correct position by the external fixator. For this purpose, it is necessary that the positioning table has a permeability for X-rays. The patient’s skin must be carefully disinfected. Furthermore, the patient must be covered with sterile drapes. If the bone fragments have shifted during the fracture, their correct position in relation to each other may be affected. The surgeon returns them to their correct position by pulling on them. A number of smaller skin incisions are then made in the region of the injured bone. This gives the surgeon access to the bone. Holes are also drilled into the bone through the incisions. The surgeon then screws elongated rods made of metal into the holes, which connect the external fixator’s outer frame to the bone. Punch screws are used to attach the appliance to the bone.They are connected to a force carrier via special jaws. The screws are inserted percutaneously. The connecting force carrier is located outside the soft tissues. After the external fixator has been attached, an X-ray examination of the patient takes place. If all the bone fragments are in the desired position, the physician can cover the entry points of the metal rods to prevent infection. The patient is then taken to a recovery room to recover from the procedure.
Risks, side effects, and hazards
There are certain risks associated with the placement of an external fixator. For example, unforeseen incidents may occur due to anesthesia, nerve injury, and bleeding. Furthermore, the development of unsightly scars as well as wound infections are within the realm of possibility. In addition, there is a risk of special complications. These include malpositions, infections of the bone, delays in bone healing, and permanent pronounced movement restrictions of adjacent joints. However, if prudent treatment planning takes place, complications can often be counteracted. After surgery, the patient begins physical therapy two to three days later. In the hospital, the physiotherapist introduces him to exercises that he can then perform in his own home. Two to six weeks later, the doctor takes further X-ray examinations. Consistent care of the external fixator is also important. Due to the metal rods, there is a risk that the wound cavity will be affected by germs. For this reason, careful cleaning of the rods with disinfectants is necessary. In addition, the wound must remain dry.
