The returned implants were evaluated and it appears the fracture of the stem was a result of fatigue.Evidence of two wear stripes and the extensive wear damage on the femoral head suggest that possible sub optimal positioning or joint laxity was a factor in the eventual component failure.It should also be noted that some of this wear damage could have occurred after failure of the stem.It was stated in the relevant "indications for use" at the time that the components were manufactured that: ¿fatigue fracture of components can occur as a result of loss of fixation, trauma, malalignment, bone resorption, trauma, or excessive weight.The root cause behind this failure mechanism is unclear, although it is possible that suboptimal cementing may have been a contributing factor.Further surgical information, radiographs and the missing portion of the stem would be necessary to determine the definite cause.
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