This report is being resubmitted for an incident that occurred earlier.Evaluation of the returned device shows the screw shank to have sheared approximately 10mm below the screw head.The larger diameter portion of the screw shank has a smooth fracture plane which is consistent with crack propagation associated with fatigue failure.It's possible that high levels of cyclic loading in the lower lumbar spine lead lo fatigue.Additionally, it's possible that the patient did not fully fuse at the instrumented levels leading to higher stress on the hardware.However , the exact cause of th:e reported issue could not be determined.
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