External fixation is a surgical method used to stabilize broken bones from outside the body. This technique involves placing a frame or device on the exterior of the injured limb, which is connected to the bone using pins or wires. It provides stability to the fractured bone, allowing it to heal while addressing other aspects of the injury.
Understanding External Fixation
External fixation uses pins or wires inserted into the bone through small incisions in the skin. These pins extend outside the body and connect to an external frame, typically made of metal or carbon fiber rods and clamps. This assembly holds bone fragments in proper alignment, providing a stable environment for healing. The device acts as a scaffold, immobilizing the fracture while allowing access to surrounding soft tissues.
The pins or wires are carefully placed to avoid nerves and blood vessels, securing bone segments above and below the fracture. The external frame then connects these pins, creating a rigid construct that maintains the bone’s length, alignment, and rotation. This setup allows the surgeon to stabilize the bone without extensive internal dissection, which can be beneficial in certain injury scenarios. Over time, the external frame may be adjusted to optimize bone alignment as healing progresses.
Common Scenarios for Use
External fixation is frequently chosen for severe open fractures, where the bone has broken through the skin. These cases carry a high infection risk due to bone exposure. External fixators stabilize the fracture without inserting internal hardware into a contaminated wound, reducing infection risk and facilitating wound care. This provides immediate stability while allowing wound management, cleaning, and soft tissue monitoring.
Another common application is in the management of comminuted fractures, which involve the bone breaking into multiple fragments. External fixation can effectively stabilize these complex fractures by holding numerous small bone pieces in place. This technique is useful when other stabilization methods are difficult due to fragment number or size. It provides necessary support for the bone to heal, even with its fragmented nature.
For unstable pelvic fractures, external fixation serves as a rapid and effective method for initial stabilization. These high-energy trauma injuries can cause significant bleeding. Applying an external fixator helps control hemorrhage and reduce the need for blood transfusions by stabilizing the pelvic ring. This immediate stabilization is crucial for managing severely injured patients, often as a temporary measure before definitive treatment.
External fixation is also a tool in “damage control orthopaedics,” particularly for patients with multiple severe injuries (polytrauma). When a patient’s condition is too unstable for lengthy internal fixation surgery, external fixators offer a quick, minimally invasive way to stabilize major fractures. This reduces further injury and allows the patient to become stable for other necessary treatments. This temporary stabilization helps prevent secondary complications and improve overall recovery.
Specialized and Temporary Applications
Beyond common acute trauma, external fixation is used in specialized procedures like limb lengthening and deformity correction. This process, known as distraction osteogenesis, involves gradually pulling apart two bone segments after a surgical cut. The external fixator is adjusted incrementally, about 1 millimeter per day, to create a small gap where new bone tissue forms. This controlled separation stimulates natural healing processes to generate new bone and soft tissue, effectively lengthening the limb or correcting deformities.
External fixators also play a role in joint fusion, or arthrodesis, a procedure that permanently joins two bones at a joint. For joints severely damaged by arthritis, infection, or trauma, external fixation stabilizes the bones in a fixed position, promoting fusion. This immobilization allows bones to grow together, eliminating pain and providing joint stability.
When a fracture fails to heal and becomes infected (infected non-union), external fixation offers a solution. The external frame stabilizes the bone, essential for successful infection treatment. This setup allows surgeons to access the infected area for debridement, removing dead or infected tissue, without compromising fracture stability. Managing the infection while maintaining bone alignment is a significant advantage in these complex cases.
Choosing External Fixation
The decision to use external fixation is influenced by several factors, often contrasting with internal fixation methods. One consideration is the injury’s nature and severity, particularly the condition of surrounding soft tissues. When there is extensive soft tissue damage, swelling, or a high infection risk, external fixation is preferred. It avoids further disruption of compromised tissues, preserving blood supply for healing.
The patient’s overall health and stability also play a significant role. For polytrauma patients or those unable to tolerate longer, more invasive surgery, external fixation offers a quick, less demanding option for immediate stabilization. It rapidly stabilizes major fractures, allowing medical teams to address other life-threatening injuries first.
External fixation offers advantages like adjustability and ease of removal. The external frame can be modified post-operatively to fine-tune bone alignment as healing progresses. Once the bone has healed sufficiently, the fixator can be removed in a less invasive procedure than extracting internal implants. This flexibility and direct wound access make it suitable for challenging orthopedic scenarios.