|
An evaluation of the returned instrument found no manufacturing, processing or design related irregularities.The instrument was found to be properly manufactured and released in accordance with the device master record.A previous investigation found that the failure mode observed in this type of event, is due to imparting excessive torsional loads to the mating instrument (reducer) during the rod reduction maneuver.Excessive load can be applied due to a tolerance gap condition between the reducer and extenders.The over-torque observation was corroborated by the two design interface analyses (dias) that were performed on the reducer/screw extender interfaces.
|