This report is being resubmitted for an incident that occurred earlier.Evaluation of the provided x-rays show the rods broke bilaterally just cephalad to the head offset connectors joining the rods to the iliac bolts between the ls and s1 screws.This is an area of high stress as the head offset connectors are connecting the spine to the ilium.The long fixation construct above also creates a large lever arm, further stressing the bottom of the construct at s1.Additionally, the double screw head had come disconnected from the bone screw.It was reported that the patient has pseudoarthrosis at l5-s1 which indicates this segment had not fused, and the construct continued to carry some of the load at this level.The rods were returned for evaluation and the fracture surfaces of the rods were found to be consistent with fatigue fracture.The diameter of the rod segments was measured in the area of the fracture and found to be within specification.It is possible that the high stress concentration in this area caused a fatigue fracture in the rods.This is consistent with the pseudoarthrosis at this level resulting in continuous motion.The patient also underwent 3 previously failed spinal surgeries.No information was available regarding these surgeries.It is possible that factors associated with these previous surgeries also contributed, such as a previous fusion at the treated levels.However, it is not possible to determine the exact cause of the reported issue.
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