A uniplane fixation device is a type of external fixator used in orthopedic surgery to stabilize broken bones from outside the body. It is applied to complex or unstable fractures, especially those resulting from high-energy trauma, where immediate internal fixation with plates and screws is not suitable. The device helps maintain the bone fragments in correct alignment, allowing for proper healing while keeping the fracture site accessible for wound care or observation. This approach often acts as a temporary bridge to definitive surgery, but it may also be used as the final treatment for certain injuries.
Device Structure and Operation
The structure of the uniplane fixator consists of three main elements: the pins, the clamps, and the external bar. Specialized screws, known as Schanz pins or half-pins, are inserted directly into the bone fragments through small incisions in the skin and muscle. These pins pass through only one side of the bone to minimize soft tissue disruption and are placed in the bone segments above and below the fracture site.
The pins are then connected to an external rod or bar using specialized clamps or connectors. The defining characteristic is that all the pins are inserted in a single plane, and the external bar runs parallel to this plane. This is why the device is called “uniplane” or “monolateral,” meaning it is attached to only one side of the limb.
The uniplane design offers high rigidity in the plane of the bar, which is sufficient for simple long-bone fractures like those in the tibia or femur. Surgeons can manipulate the clamps and the bar to adjust the bone’s length, rotation, and alignment after the pins are secured. This ability to make subtle adjustments without re-entering the surgical site is a significant advantage compared to a traditional cast.
Primary Uses in Orthopedics
Orthopedic surgeons select a uniplane external fixator when the surrounding soft tissues are compromised. This device is valuable in cases of open fractures, where the bone has broken through the skin, presenting a high risk of infection. By stabilizing the bone externally, the fixator keeps the fracture reduced while allowing medical teams full access to the wound for cleaning and dressing changes.
The fixator serves as provisional stabilization in the emergency setting for severely injured patients who may not be stable enough for a longer, more invasive surgery. It secures the limb quickly, which helps control pain and prevents further damage to the nerves and blood vessels. Uniplane fixators are also employed in the treatment of long-bone fractures, such as those in the tibia, to maintain length and alignment of the limb.
Other indications include the correction of bone deformities or gradual bone lengthening procedures. In these scenarios, the external bar often incorporates a distraction mechanism that permits the slow, controlled movement of the bone fragments over time. This controlled mechanical environment encourages new bone formation and ensures a successful outcome in complex limb reconstruction.
Patient Experience and Device Removal
Living with a uniplane fixation device requires meticulous care, as the entry points of the pins through the skin are the most common source of complications. Patients must adhere to a strict pin site care protocol, which involves regularly cleaning the skin around the pins to prevent bacteria from traveling down to the bone. This cleaning is typically done using cotton swabs and a cleansing solution, working gently away from the pin site to remove drainage or crusting.
While the fixator stabilizes the fracture, mobility is limited, and patients require assistive devices like crutches or walkers to move around. The bulky nature of the external frame can affect a patient’s psychological well-being, causing distress or anxiety related to the device. However, many patients adapt over time, and early rehabilitation is encouraged to maintain joint function and muscle strength.
Once X-rays confirm that the bone has healed sufficiently, the uniplane fixator is ready for removal. This procedure is straightforward and is often performed in an outpatient clinic or minor operating room setting. While some patients may receive minimal sedation, removal is frequently done without general anesthesia, involving the loosening of the clamps and the manual extraction of the pins. After the device is removed, the limb may require a period of protection, often through a cast or brace, and a formal physical rehabilitation program is necessary to restore full strength and range of motion.