|
Please note the corrections to b2, d1, d9, h6 method, results and health impact codes.The reported event could not be confirmed since the device was returned for evaluation and matches the alleged event.The returned nail and screws were subjected to visual inspection, which revealed that the nail had fractured at the region corresponding to the webs of the lag screw.The fractured surface exhibited pronounced mis drilling marks, which likely acted as the initiation site for crack propagation.Additionally, significant deformation was noted in both the distal and proximal sections of the nail, consistent with load transfer from the lag screw during continuous weight-bearing.The broken sections of the nail indicate a combination of brittle and fatigue failure.The presence of rest lines supports fatigue characteristics, while the shiny, smooth regions without evidence of plastic deformation are indicative of breakage in brittle manner.Severe deformation was also observed around the locking screw hole just below the lag screw region, where the peripheral geometry of the hole was noticeably distorted.Due to the outward deformation pattern, it is difficult to determine whether this damage occurred during implantation or explantation.Similar deformation features were present at the distal end, particularly around the locking and oblong holes.Both locking screws were broken in the threaded region.The threads showed signs of deformation, including flattening and bending inward.The breakage surfaces of screws similarly suggest a combined fatigue mechanism, followed by sudden brittle failure likely induced by the abrupt load redistribution at the moment of nail failure.A review of the device history for the reported lot did not indicate any abnormalities.No corrective actions are required at this time.A review of the labeling did not indicate any abnormalities.No indications of material, manufacturing or design related problems were found during the investigation.Based on investigation, the breakage of device was confirmed to be combination of fatigue and brittle in nature.No product related issue could be detected during the performed investigation of the returned device.Regarding the root cause of the implant failure no conclusive statement can be provided, because key clinical information (e.G.X-rays in different planes, clinical status, patient activity, assessment of the treating physician or operation reports) is missing.The root causes in such cases are often complex and multifactorial and cannot be determined scientifically without this decisive evidence.Due to these limitations, we are unable in such cases to provide statements about the patient, the procedure and/or the device in relation to cause of the failure.If any additional information is provided, the investigation will be reassessed.
|
