An external fixator is an apparatus that is mounted to the outside of the body to lengthen or straighten limbs. External fixators can also be used to treat fractures in some cases. The two types of external fixators that are used in limb lengthening are:
- Monolateral fixator: This fixator is mounted to one side of the limb (typically the femur and humerus). Monolateral fixators are usually placed on the outer thigh or arm or the inner leg. Sometimes, they are used to treat broken bones, especially if the bone or skin is badly damaged.
- Circular fixator: This fixator, or frame, is mounted around the limb. The frame is made of at least two carbon fiber or aluminum rings connected by four or six struts.
For either type of external fixator, monolateral or circular, the frame is mounted to the body by placing special pins or wires through the skin and into the bone. There is a special coating (hydroxyapatite) on the pins to allow them to stick to the bone. This coating decreases, but does not eliminate, the risk of pin infections , which are common but preventable. It’s extremely important that the pins are cleaned daily.
What does an external fixator look like?
Your child will likely require:
- Weekly doctor visits
- Multiple adjustments to the frame (on a daily basis)
- Physical therapy
- Crutches to help with daily activities
How can my child get dressed with an external fixator?
Dressing around the external fixator can sometimes be challenging—particularly if it is on the femur—but your doctor can help guide you and your child through the process.
When can the external fixator be removed?
Your child’s doctor will work with you to decide when the treatment is complete. Before the external fixator is removed, your child’s doctor will likely want your child to be walking without any limitations. The external fixator is removed in the operating room under general anesthesia. Once it is removed, your doctor may place your child’s leg in a walking cast for a short period of time or require him to use crutches for three to four weeks, or until the bone is stronger.