Lot mfev (2): the returned devices were inspected visually and functionally.Visual inspection did not reveal any damage, deformation, or obvious signs of wear.Functional inspection during bench testing could not replicate the described failure mode.For functional testing, the inserter and a model screw were assembled; the hexalobe fit into the screw without difficulty.No jamming was observed when disengaging the inserter from the screw.Complaint history was reviewed for the reported lot number and no previous complaints were identified.A conclusive root cause could not be determined with the available information.Factors which may have contributed to the event include the use of excessive force, use of the device at a difficult angle, and hard bone quality of the patient.Lot unknown (1): the device was not returned for evaluation.Device history records could not be reviewed without either the device or a valid lot number.Complaint history was reviewed for the reported catalogue number and five similar complaints were identified.The user may experience difficult disassembly of the screw inserter and screw if the hexalobe tip is deformed prior to insertion or becomes deformed during insertion, the inserter is used with complex maneuvers, or if the user is attempting to disengage the inserter in a position not coaxial to the screw shank hex (i.E., removing the device at an angle from the screw).A surgeon's technique (burying the screw, using an entry point and/or screw trajectory that places the screw head closer to the anatomy, etc.) may contribute to this failure mode as well.A conclusive root cause cannot be established.If additional information is received or the device is returned for evaluation, the investigation will be reopened and updated.
|