Polished Tapered Stem

Cemented stems are classified into taper-slip and composite beams on the basis of their mechanical behavior in the femoral canal [1, 2]. In the taper-slip concept, the polished tapered (wedge-shaped) stem subsides into the cement mantle when loaded. This causes compressive stress on the bone–cement mantle, and the load is transferred to the femur through the bone–cement interface [2]. Bone cement is weak against bending stress but strong against compressive stress, and these properties support the long-term stability of polished tapered stems [3]. The polished tapered stem subsides slightly into the bone cement mantle under load, rises slightly when unloaded, and subsides slightly again when reloaded [4]. The polished surface has a very low risk of generating metal or cement wear debris at the stem–cement interface during this cyclic movement as well as of osteolysis derived from wear debris.