The reported event could be confirmed, since provided x-ray image shows the dislocated screw which was confirmed by a healthcare provider (hcp).A device inspection was not possible since the affected device was not returned, and no other evidence were provided for investigation.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.Since x-rays were provided, formal medical opinion was sought from an experienced medical expert as: at least both distal screws have been backed out on the follow up x-ray.There is a hypertrophic bone area at the fracture site, which does not show clear signs of non-union, but suggests some movement at the fracture site to allow for the forces that led to the back out of the screws.This seems to be a left sided nail and there is a back out of the screws and potentially there is a hypertrophic delayed or non-union, however, it remains unclear, whether some constructive specifications of the nail creates any specific issue in this particular case.The probable root cause can be either or combination of the following factors, firstly, patient related factor as both the location of the fracture and the pretty horizontal fracture line, so the fracture patterns allows movement as mentioned above.Secondly, surgeon related factor as the surgical technique was okay, although a pretty broad fracture gap can be seen in the lateral view.This also may have contributed to the observed complications.Lastly, device related factor cannot be completely excluded that the location and the orientation of the holes in the combination with unfavorable fracture pattern and localization (here: horizontal fracture line at the height of the metaphysis) may have had an influence on the backing out of the screw.Based on investigation, the root cause was primarily attributed to the patient related factors such as fracture location and pattern (horizontal fracture line) along with a secondary factor such as user related (inadequate reduction) and a possible device related factor (positioning of the holes).The surgeon could have considered additional measurements to ensure the stability of the construct, given the complications reported.Simultaneously, r&d has been notified about the probable device related factors.If any additional information is provided, the investigation will be reassessed.
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