The reported event could not be confirmed, since the returned device is conforming to specifications and is fully functional.The device inspection revealed the following: the received nail showed no evident signs of damage.The alleged inner threads were found to be in ok state.The ¿nylstop¿ in the set screw showed grooves which suggests that the set screw successfully engaged with the inner threads in the nail.However, the tip of the set screw showed no sign of indentation which is normally observed upon a successful contact with the lag screw.The kit lag screw was not received, so a confirmation from the lag screw side about contact with set screw could not be done.The received nail and set screw were assembled with a sample ti lag screw.All the 3 components could be assembled firmly and securely.Hence the alleged event could not be confirmed or reproduced.A review of the device history for the reported lot did not indicate any abnormalities.No corrective actions are required at this time.No indications of material, manufacturing or design related problems were found during the investigation.A review of the labeling did not indicate any abnormalities.Based on the above investigation, the root cause of the failure is user related.It is clear that the set screw was not engaged with the lag screw entirely, it wasn¿t pushed down enough, hence secure locking could not be achieved.This is therefore classified as deviation from surgical technique.The op-tech states: ¿push the set screwdriver down until you are sure that the set screw engages the corresponding thread in the nail.While pushing down the assembly, you may feel a slight resistance.Turn the screwdriver handle clockwise under continuous pressure.You may notice a resistance when turning the set screw.This is because the set screw thread is equipped with the ¿nylstop¿ system to prevent spontaneous loosening.This is not the final position for the set screw.Keep on turning the set screw until you feel contact in one of the grooves of the lag screw.To verify the correct position of the set screw, try to turn the lag screwdriver gently clockwise and counterclockwise.If it is not possible to turn the lag screwdriver, the set screw is engaged in one of the grooves.If the lag screwdriver still moves, recorrect the handle position and tighten the set screw again until it engages in one of the four grooves.After slightly tightening the set screw it should then be unscrewed by one quarter (1/4) of a turn, until a small play can be felt at the lag screwdriver.This ensures a free sliding of the lag screw.Make sure that the set screw is still engaged in the groove by checking that it is still not possible to turn the lag screw with the lag screwdriver.Note: do not unscrew the set screw more than 1/4 of a turn.¿ if any further information is provided, the complaint report will be updated.
|