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The devices was available for evaluation along with associated parts including a single creo threaded locking cap, a single 5.5mm curved rod, titanium alloy, 100mm length, and a single creo one 7.5x35mm robotic, self-drilling, modular screw.It was reported that the screw head disconnected from the screw at the right side s1 on an l3-s1 construct originally completed on (b)(6) 2022.The patient had a revision/extension of the fusion from l2-pelvis done on (b)(6) 2024.During the surgery is when the screw head was found to be disassociated from the screw shank.Review of the provided ct section shows the head of the screw within s1 is dissociated from screw shank.All parts were evaluated and imaging was taken.Visual inspection indicated that the head of the screw shows significant wear along where the screw head is attached and within the hexalobe feature.One of the clamps has been completely fractured perpendicular to the axis of the screw assembly.The other clamp shows a fracture half way through the same perpendicularity.The bottom of the saddle exhibits deep gashes and signs of deformation and these same marks can be seen on the tops of the clamps that connect to the same region where deformation is present.The body of the screw head exhibits signs of deformation along the bottom ring and a deep gash within one of the sides.Fracture and dissociation are indicative of high forces or repetitive stresses being placed on the screws and a lack of fusion over time.The orientation of the fractured clamps are consistent with exposure to high forces which is possible at the ends of a screw construct.However, it is unknown exactly how this failure may have occurred or which factors were the primary contributors to the failure.The surgical and post-operative conditions cannot be replicated, therefore, no determinations could be made as to the cause of the reported issue.
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