A visual inspection was performed and found the underside of the tulip to be deformed.Proximal threads are deformed.A functional inspection performed found that the tulip is jammed and has lost all ability to articulate on the screw shank.Tulip is too proximal on the shank, evidence of screw being inserted too far.Location of tulip deformation indicates screw was most likely inserted too far and the base of the tulip became jammed on bone.The bone may have caused the tulip to disengage.Device history records were reviewed for the corresponding lot and no relevant issues were identified.Complaint history record review was performed for this lot and subject catalog number, and no adverse trends were observed.The customer reported an event of a xia ii lp polyaxial screw tulip jamming intra-op which was confirmed via visual and functional inspection.Initial report states that once the screw was inserted into the patient the tulip was jammed and could not be moved.The surgeon attempted to remove the screw and the tulip disengaged from the screw shank.The xia surgical technique was reviewed: ¿with the pedicle pathways prepared and proper screw length and diameter determined, the screw is prepared for insertion.¿ note: ¿the poly axial screws may lock upon insertion.Use the inserter to unlock the heads before introducing the rod.¿ the most likely cause of the reported event was determined to be due to screw tulip contacting bone during insertion.Over insertion of screws can cause the tulip to jam on the bone.Contact from the bone can cause tulip to disengage.
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