Method: visual inspection, material analysis, product history review, complaint history review, labelling review, risk assessment.Result: the customer reported event was confirmed via visual inspection and x ray.The returned screw was fractured at the screw shank.The fractured piece was not returned.Device was sent for material analysis.The fractured screw was visually consistent with a fatigue fracture.The fracture surface was too damaged post fracture to determine the exact mode.The elemental constituents were consistent with the print.No material or manufacturing defects were found.Manufacturing records were reviewed for the corresponding lot and no relevant issues were identified.It was reported that the screw was implanted in (b)(6) 2015.According to the ifu, "while the expected life of spinal implant components is difficult to estimate, it is finite.These components are made of foreign materials which are placed within the body for the potential fusion of the spine and reduction of pain.However, due to the many biological, mechanical and physicochemical factors which affect these devices but cannot be evaluated in vivo, the components cannot be expected to indefinitely withstand the activity level and loads of normal healthy bone.Fatigue fracture of spinal fixation devices, including screws and rods, has occurred." conclusion: the most likely root cause is fatigue fracture due to length of implantation.
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