By the event description, it appears that stem subsidence due to stem under-sizing (surgical factor) is the root cause of the hip dislocation reported.The check of the dhr of the lot#: of stem involved (lot#: 201516301) did not show any anomalies on the 30 stems manufactured with these lot#.This is the only similar complaint reported on this lot#: (according to our records, 25 stems with this specific lot#: were implanted).Explants were not available to be sent to lima corporate.A pre-revision surgery x-ray (dated on (b)(6) 2016) was provided and then analyzed by our medical consultant for a critical judgment.Medical consultant's remarks are reported here below: "i do not believe that the subsidence of the stem was due to undersizing.On the x-ray (dated on (b)(6) 2016) - shortly before the revision - i see three cerclage wires, fixing a periprosthetic fracture of the proximal femur.This may have occurred before or during the primary procedure.In such a case the surgeon must go for a stem with stable more distal fixation.The h-max stem is not appropriate for such conditions, especially the lateralized version.It relies mainly on a proximal fixation which in this case must have been severely compromised.A modular revision stem would have been indicated in such case".In fact, the surgical technique provided with h-max s stems specifies that these stems have a proximal fixation, not a distal one.According to the above medical judgment, likely cause for stem subsidence and need of revision surgery was a suboptimal choice of initial implant (a different type of stem - with distal fixation - should have been chosen by the surgeon).No indication that the stem itself contributed to the event: event not product related.Pms data: a total of six revision surgeries due to subsidence of h-max s lateralized stems were reported to limacorporate, on a total of 12.338 h - max s lateralized stems marketed ww since 2009 giving a revision rate of 0.049%.According to our investigation, none of these complaints was product - related.Lima corporate will keep monitoring the market to promptly detect any other similar issue.
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