External Fixator Use in Acute Trauma

Ahmed Thabet, M.D.
Texas Tech Health Science Center at El Paso

Introduction:

Fractures, also known as broken bones commonly occur in the injured. These types of injuries can happen due to motor vehicle collision (MVC), motorcycle accidents, falls, sports related trauma, indoor trauma and intentional trauma from assault. The severity of injuries varies from simple to complex fractures. The complex injuries include not only broken bones but extend to the soft tissues in the region (skin, muscles, nerves, arteries). Fractures with open skin wounds or blood-filled blisters are special entity and needs more complex treatment. The open wounds increase the risks for complications such as infection, delayed fracture healing and may even lead to limb loss. Bony fragmentations at the fracture ends, fractures at multiple locations on the same bone or bone loss can complicate the treatment of these injuries.

Open fractures are complex injuries with increased risk of complications. The open wounds can make a significant impact on treatment course and outcomes. The blood-filled blisters, severe swelling and bruising

Causes:

1- Motor vehicle collisions and motorcycle accidents
2- Sports related injuries
3- Indoor trauma
4- Falls
5- Assault

Symptoms:

The patient usually presents to emergency room with severe pain, bleeding, inability to use the extremity and crooked position of the bones. Not infrequently, the patient has multiple injuries including the head, chest and the belly. The patient may be very sick and need admission to the intensive care unit.

 Doctor Examination:

The examination includes the patient’s temperature, breathing rate, blood pressure, and heart rate to make sure that the patient is stable. The extremity exam includes the size of any open wounds about the fracture and documentations of blisters, bruising and the degree of swelling. Special attention is given to blood flow and the ability to move and feel the extremity. The size of the skin wound and the degree of contamination of the wound are key factors in fracture classification. Fractures with skin wounds <1cm are considered grade I, fractures with skin wounds between 1-10 cm are considered grade II, and fractures with skin wounds greater 10 cm or with extensive soft tissue damage are considered grade III. The grade III can be further classified into A: skin wound can be closed, B: open wounds needing complex closure technique such as muscle flap for closure, C: fractures with arterial injury that needs repair.

Treatment:

• These complex fractures with open wounds, severe swelling and blood-filled blisters,
multiple fractured pieces (called comminution of the fracture), and bone loss need a different approach from more simple fractures. Some fractures are not ideally treated with internal fixation methods (plates or nails), in which case an external fixation method is utilized. The external fixators are attached to the bone through pins or wires above and below the fracture(s). The bones are then aligned and these pins and wires are connected to each other with bars and clamps. The pins and wires may need to be arranged differently in different injury types.
• The external fixators can be used in these acute injuries as a temporary method until the soft tissues are ready for internal fixation, or as the definitive treatment until full fracture healing. The configuration of the external fixator and the number of the fixation’s points will vary according to the goal of using the external fixator.
• Circular ring based external fixators are used as definitive fracture fixations. These fixators allow stable fixation to achieve fracture fixation and can be easily adjusted to improve the position of the fracture. Web-based software computer can be used for adjusting the bony alignments. These types of adjustments may be necessary in cases with bone and soft tissue loss.
• The main advantages of the external fixators include their minimally invasive application without large incisions, minimizing of the risk of the infection by keeping the metal away from the injured soft tissues, the ability to begin early weight bearing, easy wound care to the traumatic wounds since no splint or cast is needed, the option to continue to modify the position of the bone as needed after surgery, and the ability to provide the stable fixation until full fracture healing.

Outcomes:

The outcomes of external fixators are generally good. Fracture healing, normal bone alignment and good functional outcomes can be achieved. The limitations of external fixators in acute fracture managements are:
• Pin-site infection. In most cases this is limited to the soft tissues and can be treated by antibiotics and local pin care. If the infection extends to the bone, it usually needs surgical cleaning and replacement of the pin
• Skin scarring from the pin sites
• Inconvenience and discomfort of having the external fixator on the limb
• Risk of refracture after frame removal either through the pin sites or the original fracture site
• Challenges with stiffness when an external fixator crossing a joint is worn for a prolonged period of time