Image review: pre-revision and post revision x-rays for thoraco lumbar stabilization construct provided.In two of the provided images, there appears to be broken screw at the inferior level of a construct around a burst fracture.Each of the screws is connected probably 2 degree to osteoporosis.The construct was revised to a compacting graft at the fracture level.Hardware failure was likely 2 degree to failure of fusion given osteoporosis.Product analysis: visual, microscopic and dimensional evaluation confirmed the bone screw disassembled from the head.The ring and crown were still assembled in the head.A portion of the ring has been sheared through the cross-sectional area, with the remaining portion of the ring still seated in the groove of the head.The retaining ring is fully seated but has been deformed and partially sheared off.The deformed and sheared areas are on either side of the retaining ring gap and would reduce the force required for head disassembly.The diameter of the bone screw head in the undamaged area was checked and meets print spec.The above observations are consistent with overload as the mechanism of failure.If information is provided in the future, a supplemental report will be issued.
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