In planning and research prior to design of the ARROW-LOK™ implant, the surgeon design team identified performance objectives for the new implant that would offer clinical advantages over current implant alternatives. These design imperatives included:
- Keep completely intramedullary with no parts of the implant exposed outside the skin.
- Maintain the initial compression applied at insertion.
- Resist the rotational and pull-out forces affecting the lesser toes.
Simple implant design
- Avoid introducing potential stress-risers and the need to assemble intraoperatively by developing a one-piece design.
- Provide anatomic sizing to fit a broad range of patient anatomy.
- Fit the patient’s natural toe anatomy by providing a neutral and 10° plantar angle.
- Minimize bone removal with a low-profile design.
- Maintain uniform strength characteristics throughout the implant.
- Ensure the product material has a proven long-term biocompatibility so it can be safely implanted permanently. Will not require removal like the K-wire.
- Create an operative technique similar to that for K-wire fixation with little additional complexity, such as drilling, tapping, or bulky instrumentation.
- Remove little or no bone when preparing the bone for implant insertion while compacting cancellous bone to enhance stable fixation.
- Enable variations in implant placement with respect to the fusion site without any impact on implant effectiveness.
- Allow enough versatility within the interaction between instrument and implant such that the technique may adapt to surgeon preference and patient anatomy.
- Must be biocompatible, clinically proven, extensively studied, and commonly used for permanently implanted medical devices.
- Bending and fatigue characteristics able to endure the forces exerted on the lesser toes without having to add unnecessary material volume.
- Capable of being efficiently manufactured to ensure reproducible results.
- Does not require special handling or storage either preoperatively or intraoperatively.
- Instrumentation resembles those with which surgeons are familiar.
- Emphasize simplicity to ensure reproducible results.