A cannulated screw looks like an ordinary bone screw until it's cut in half: running through its center is a hollow channel from tip to head. That single design feature changes how the screw is placed. Instead of drilling a pilot hole and hoping the trajectory lines up with the fracture plane, a surgeon first places a thin guidewire under imaging guidance, confirms its position, and then advances the cannulated screw directly over that wire. Cannulated screws are widely used across orthopedic trauma surgery precisely because this guided approach supports accurate, repeatable placement through small incisions.
What Makes a Screw "Cannulated" in the First Place?
The defining feature is the hollow core running the full length of the screw shaft, sized to slide over a guidewire of matching diameter. This is different from a solid-core screw, which must be positioned freehand or with the help of an external drill guide alone. Because the guidewire can be advanced, checked on imaging, and repositioned before any screw is inserted, the surgical team effectively confirms the fixation trajectory before committing to a definitive implant path. Cannulated screws are typically self-tapping or paired with a cannulated drill bit, and thread patterns vary depending on whether the intended use is compression across a fracture line or simple fixation without compression.
How Does Guidewire-Assisted Placement Actually Work?
The general workflow follows a consistent sequence regardless of anatomical site. A guidewire is inserted through a small skin incision and advanced across the fracture under fluoroscopic imaging. Its position is checked in at least two imaging planes to confirm it crosses the fracture appropriately without entering a joint space or violating an unintended cortex. A cannulated drill or reamer is then passed over the wire to prepare the bone, followed by the cannulated screw itself, which threads down the same path the wire established. The guidewire is removed once the screw is seated, or, in staged techniques, once the intended number of screws are confirmed and sequentially placed.
Where Are Cannulated Screws Commonly Used?
This fixation approach is well established across several fracture types where minimally invasive access and accurate trajectory both matter:
- Femoral neck fractures, where percutaneous cannulated screw fixation is a widely used technique, often placed in a triangular configuration for rotational stability.
- Scaphoid fractures, where the small bone and limited surgical corridor make guidewire confirmation particularly useful before committing to a screw path.
- Ankle and syndesmotic injuries, where cannulated screws can stabilize the distal tibiofibular joint or specific malleolar fracture patterns.
- Select small-fragment and periarticular fractures where a percutaneous, image-guided technique is preferred over an open approach.
The common thread across these applications is a fracture pattern that benefits from a confirmed screw trajectory and a less invasive surgical footprint than traditional open fixation.
What Are the Practical Advantages of a Percutaneous Technique?
Because the guidewire and cannulated instruments allow fixation through a small incision, percutaneous cannulated screw techniques are generally associated with reduced soft tissue disruption compared with open approaches for the same fracture pattern. This can be a relevant consideration in patients where soft tissue viability, wound healing capacity, or surgical time are concerns. It is important to note that the appropriateness of a percutaneous, cannulated approach versus an open technique depends on fracture pattern, displacement, associated soft tissue injury, and the clinical judgment of the treating surgeon — a percutaneous technique is not universally applicable to every fracture.
CytroFIX Cannulated Screws
INVAMED's orthopedic division, Cytronics, manufactures the CytroFIX Cannulated Screws, designed with the cannulated architecture described above to allow placement over a guidewire using a percutaneous technique. As with other devices in the CytroFIX line, the cannulated screw system is intended for use by trained orthopedic surgeons who determine the appropriate screw size, configuration, and fracture indication on a case-by-case basis.
Do cannulated screws provide the same holding strength as solid screws?
Cannulated screws are engineered for their intended fixation role, though the hollow core does mean a slightly reduced cross-sectional area compared with an equivalent solid screw of the same outer diameter. In clinical practice, screw selection, number, and configuration are chosen by the surgeon to achieve adequate fixation for the specific fracture pattern, and cannulated designs remain a standard option across many trauma indications.
Can cannulated screws be used without a guidewire?
Technically a cannulated screw could be inserted without first placing a wire, but doing so removes the main advantage of the design. The guidewire step is what allows trajectory confirmation on imaging before the screw itself is committed, so in standard practice cannulated screws are almost always placed using the guided technique they were designed for.
Are cannulated screws removed after the fracture heals?
This depends on the fracture location, screw size, patient symptoms, and surgeon preference. Some cannulated screws, particularly in small bones or near joint surfaces, are removed if they cause irritation or interfere with adjacent structures, while others are left in place indefinitely if asymptomatic. The decision is individualized and made in consultation with the treating orthopedic surgeon.
To review other trauma fixation devices in this category, visit orthopedic trauma solutions on invamed.com.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.