The reported event could be confirmed, since the device was returned for evaluation and matches the alleged failure mode.Device inspection revealed the following: the received nail is completely broken in the webs of the proximal lag screw hole.Heavy explantation marks were observed on the inner surface of the hole and the fracture surface as well, mostly in the distal segment.Slight drill marks were found at the lateral entrance of the hole on both the sides.This may have contributed to mechanical weakening of the construct.The extent of this influence cannot be quantified.However, more significant thing to note apart from the drill marks was the sign of overloading.Bearing points of lag screw at the medial edge of the proximal hole showed significant deformation, indicating towards high compressive load.Signs of overloading were also evident at the distal oblong hole.The breakage pattern resembles a fatigue breakage, having equal portions of fatigue zone and instantaneous zone indicating that the breakage initiated in a fatigue manner but quickly broke instantaneously under high compressive loading.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.A clinical opinion regarding the event was sought from an independent medical professional.Unfortunately, a lot of patient details and event details were missing, therefore assessment was done strictly on the basis of available x-rays and may include some assumptions.The medical expert opined that there is a clear sign of a loss of initial reduction (compared to the reduction during surgery).The lag screw moved lateral and the angle seems to have changed, but this movement is not quantifiable through the available pictures.This movement suggests that the initial fixation may have been unstable from the start.From the x-ray after 6 months, signs of breakage could be observed.Compression couldn¿t be achieved, and movement of fracture continued leading to fatigue and ultimately breakage.It could be said that the fracture did not heal after the initial surgery.Based on the above investigation and available information, the root cause of the failure is a combination of both user related and patient related factors but predominantly is patient related.Significant deformation and signs of overloading were observed in the returned nail around the bearing point of lag screw and in the distal hole as well, which indicates towards application of high compressive loading leading to breakage in a fatigue manner.Also, strictly based on the available radiographs, an unstable fixation and non-union was observed which also led to additional loading on the nail.If any further information is provided, the complaint report will be updated.
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