Cannulated Headless Screw (Fully Threaded) System

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Cannulated Headless Screw (Fully Threaded) System

Tom Fischer, Sudhir Warrier, Alex Lluch, Martin Langer, Stephen Tham

Fig 1: The Cannulated Headless Screw System - Fully Threaded

Developed by members of the Hand Expert Group and approved by the AO Technical Commission in September 2025, the Cannulated Headless Screw (Fully Threaded) System (Fig 1) is indicated for use in bone reconstruction, osteotomy, arthrodesis, joint fusion, fracture repair, and fracture fixation of bones appropriate for the size of the device. The initial product launch in 2025 will focus on hand and wrist procedures (screw diameters 2.0-4.5 mm).

The new system was developed as a line extension to the Cannulated Compression Headless Screw (CCHS) System, approved in 2019 with indications for the foot and ankle. The use of cannulated screws follows the principles of interfragmentary screw fixation and aims to optimize screw position.

The new screw design incorporates a patented self-tapping, self-drilling screw tip that allows for precise placement. The screw cannulation feature allows placement over a guidewire to facilitate better accuracy before drilling or screw insertion (Fig 2). Containing a comprehensive range of implants, the system is engineered to meet the needs of patients with diverse anatomy (see Details tab below).

Details
Disclaimer

The Cannulated Headless Screw (Fully Threaded) features a constant thread pitch and is fully threaded with a non-compressive screw design. With self-drilling and self-tapping elements (Fig 2), the cutting tip design is identical to that of CCHS. Screws are available in a range of diameters (2.0, 2.5, 3.0, 3.5, 4.0, 4.5 mm) and in lengths from 10 mm – 110 mm (Fig 3). Screws are manufactured in titanium alloy (Ti-6Al-4V ELI) and are cannulated for use with a guide wire.

For ease of handling, the screws are color-coded to the instrumentation in a schema identical to that of CCHS (Fig 3). The new system is available in sterile and non-sterile implant and instrument packaging options and is provided in modular sets. A significant advantage for hospital inventory management is the similar geometry of the new screws and CCHS, offering compatibility with CCHS screw racks, graphic cases, and instrumentation.

Fig 2: Design features of the Cannulated Headless Screw - Fully Threaded

Features and Benefits of the new Cannulated Headless Screw (Fully Threaded) System

Unique angled cutting tip: increased sharpness at the screw tip may reduce surgeon effort to achieve screw insertion, allowing better final screw alignment.
Stiffer Guidewire (CoCr): may reduce guidewire deflection during screw insertion, allowing the surgeon to better judge screw depth and trajectory, and ultimately to place the screw more accurately.
Comprehensive options: the extensive range of screw diameters and lengths in the new Cannulated Headless Screw (Fully Threaded) System addresses the complexity and unforeseen challenges in surgical procedures arising from varying patient anatomy.
Broadened portfolio: previously, only cannulated compression headless screws were offered. This line extension introduces fully threaded, constant pitch headless screws that are non-compressive.

Fig 3: Range of implants and instruments included in the Cannulated Headless Screw (Fully Threaded) System.

Indications in EU and US

The Cannulated Headless Screw (Fully Threaded) System is indicated for use in bone reconstruction, osteotomy, arthrodesis, joint fusion, fracture repair, and fracture fixation of bones appropriate for the size of the device. Screws are intended for single use only.

Contraindications

The implant should not be used in a patient who has current, or who has a history of:

Local or systemic acute or chronic inflammation;
Active infection or inflammation;
Suspected or documented metal allergy or intolerance

Fig 4: The new Cannulated Headless Screws (Fully Threaded) System offers comprehensive options for surgical procedures in the wrist and hand.

Hazards and labeling

Due to varying countries’ legal and regulatory approval requirements, consult the appropriate local product labeling for approved intended use of the products described on this website. All devices on this website are approved by the AO Technical Commission. For logistical reasons, these devices may not be available in all countries worldwide at the date of publication.

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