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- Discussion:
 - proximal medial, distal lateral shift (medial mig)
 - stem rotates around the center point;
 - medial stem pivot is caused by medial migration of proximal portion of femoral stem;
 - lateral migration of the distal tip results from inadequate superomedial and inferolateral cement support;
 - this may produce a fracture of the cement at midstem and of sclerotic bone lateral to the tip of the stem