An external fixator is a medical device used to stabilize broken bones from outside the body. It holds bone fragments in alignment, facilitating healing. For tibia fractures, external fixators provide stability when other methods may not be suitable. The device acts as a rigid support system while the bone mends.
Why an External Fixator is Used
An external fixator is often chosen for tibia fractures where internal fixation, such as plates or rods placed inside the body, is not ideal. This includes severe or open fractures, where the bone has broken through the skin, increasing the risk of infection. In such cases, the external nature of the fixator allows for easier access to the wound for cleaning and managing soft tissue injuries.
The device is also employed for comminuted fractures, where the tibia is shattered into multiple pieces, as it can provide stable alignment for these complex breaks. When there is significant bone loss or a bone defect, an external fixator can help maintain space and stability.
It is also used in cases of non-union, where a fracture has failed to heal over several months, sometimes involving distraction or compression to stimulate healing. Furthermore, external fixators are utilized in procedures for limb lengthening or correcting bone deformities, offering adjustable support for gradual changes.
How an External Fixator Works
An external fixator consists of several components to stabilize the tibia. Metal pins or wires are inserted directly into the bone through small incisions in the skin and muscle. These pins, typically 3.0 to 5.0 mm in diameter, are designed to be approximately one-quarter to one-third of the external bone diameter.
The pins are then connected to an external frame using clamps and connecting rods. The frame provides rigid support, holding the fractured bone segments in their correct anatomical position. This external assembly allows for precise adjustments to be made to the alignment of the bone fragments without further surgery.
Some fixator designs, like circular or triangular constructs, offer varied levels of stability and can be adjusted to correct multi-planar deformities. The pins are often coated with hydroxyapatite to enhance their grip within the bone and reduce loosening.
Living with an External Fixator
Pin site care is a primary concern, as the areas where the pins enter the skin are susceptible to infection. Regular cleaning of these sites, often daily or every other day, is necessary to prevent complications. Consistent monitoring for signs of infection, such as redness, discharge, or pain, is important.
Pain management is also a common consideration, which can often be addressed with oral analgesics. Mobility and weight-bearing status will depend on the fracture type and the stability of the fixator. While some circular fixators may permit early full weight-bearing, others may require non-weight-bearing or partial weight-bearing with crutches or a walker. Fatigue can be a significant factor due to the increased effort required for movement, making it helpful to plan activities and prioritize tasks.
Hygiene routines may need modification; showering with the frame is generally permissible as long as pin sites are not infected, but submerging the frame in water should be avoided. Thorough drying of the frame and pin sites after showering is important. Clothing may need to be adapted to fit over the bulky frame. Psychological adjustments are also common, and maintaining social connections and engaging in enjoyable activities can support overall well-being during the treatment period.
Recovery and Removal
The external fixator is typically removed once the tibia fracture has sufficiently healed, which can take several weeks to many months depending on the injury’s severity. The removal procedure is usually performed as a day case, and it often does not require general anesthesia. Specialized wrenches are used to remove the external frame and pins.
Immediately after removal, a cast or brace may be applied to provide continued protection and support to the healing bone. The pin sites will scab over, and it may take 6-8 weeks for the holes in the bone to start healing.
Physical therapy is a significant part of the post-removal recovery process, aiming to restore strength, range of motion, and mobility in the leg. Exercises such as walking, biking, and stretching are often recommended, while high-impact activities are typically avoided until the bone is fully consolidated.