The customer reported event of a es2 integrated blade screw tulip disengagement post-op was confirmed via visual inspection and provided x rays.Visual inspection: the screw was returned with the tulip disengaged from the screw shank.The tulip locking ring was deformed.The shank bulb had a deep and angled rod indentation, indicative of tulip angulation and overtightening.Device and complaint history records were reviewed for the corresponding lot and no relevant manufacturing issues or similar complaints were identified.As the disengagement was discovered on the day of the surgery, the screws most likely disengaged during the initial surgery.The x ray provided, indicated one screw was disengaged.The compromised construct likely caused additional stress on other screws, causing them to disengage as well.It cannot be determined which of the three screws returned was the first to disengage.It is unknown what torque the blockers were tightened to or if anti-torque was used, however, the surgical technique states they must be tightened to 12nm and anti torque must be used.Based on the deformation found on the returned screw, the most likely cause is overtightening of the blocker causing the tulip to disengage.
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