Affixus Tibial Nailing System - 4mm screws

The Affixus Tibial Nailing System with 4mm screws is a long bone nailing system designed for temporary stabilization and fixation of tibial fractures and osteotomies, including proximal, metaphyseal, distal, closed, open, and pathologic fractures, as well as non-unions, malunions, and deformity corrections. The system consists of titanium alloy implants (Ti-6AL-4V) with versatile locking options and is available in multiple lengths and diameters to accommodate different anatomical needs.

The proposed device introduces 4mm cortical bone screws made of Ti-6AL-4V with a double-lead thread design and self-tapping tip, available in lengths from 20-90mm. All other components—including materials, MRI conditional status and language, sterilization methods and validations, packaging materials and validations, shelf life validations, and biocompatibility—are identical to the primary predicate Affixus Tibial system cleared under K241651.

Mechanical testing per ASTM F1264 Annex 4 (construct bending fatigue strength), ASTM F543 Annexes 1-4 (screw torque, breaking angle, insertion/removal torque, pullout strength, and self-tapping performance), and MR compatibility evaluation per ASTM F2182, F2052, F2119, and ASTM 2213.

The device achieves substantial equivalence because the 4mm screws are a minor design addition to an already-cleared system; they use identical materials, sterilization, packaging, and biocompatibility to the predicate; they feature similar technological characteristics and design principles; non-clinical testing demonstrates they meet or exceed established mechanical performance standards without raising new safety or effectiveness questions; and the indications for use remain identical to the primary predicate device.