The mayfield modified skull clamp (a1059) was returned for evaluation: device history record (dhr): the dhr was reviewed and shows no abnormalities related to the reported failure.Failure analysis: investigation of the returned unit shows that the lock has rotational and lateral movement and a residue buildup is present.New components were added to replace worn internal parts.Also, the skull clamp base has severely worn starburst teeth that will require the clamp base to be replaced.To resolve the issues, the roundhead screw, skull clamp base, roll pins, adjustment screw, label, washers, ball bearings, o-ring and wave springs will be replaced along with general cleaning and maintenance performed.Root cause: the complaint is confirmed via inspection of the unit.The lock was loose and unit required replacement of worn parts and cleaning.The probable root cause is routine use and wear of the unit.No further investigation is required based on the acceptability of risk and no adverse trends identified.This will be monitored and trended going forward.At present, we consider this complaint to be closed.
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