Failure of the stem in total hip replacement

Abstract
Summary Thirteen failed stem of Total Hip Replacement were studied: 9 were Charnley THR from an homogeneous series, which gives an incidence of 2.4% of stem fractures with a follow-up of 9–16 years; 4 were Mueller THR. Fatigue fracture of the stem occurred by defective support of the proximal part of the femur, following resorption of the calcar. In all cases reactive tissue to foreign body particles, metal and polyethylene, was found where bone resorption occurred. In Mueller THR wear of the cup produced the large amount of polyethylene particles; in Charnley THR metal particles prevailed and corrosion of the stem is suggested to be the initiating factor.