The story behind polished stems
There are two major stem philosophies in cemented stems. The first one claims that a cemented stem should be designed to remain fixed in the cement mantle. In other words, no matter how long the stem has been in the cement mantle, it should not subside. These stems typically have a collar to help them stay in place, and tend to have rougher surfaces to increase the fixation between the cement mantle and the stem. Additional features, such as grooves or wings, are also utilized to increase stem stability. SPECTRON^◊ and SYNERGY^◊ belong to this category.

Surgeons who use polished stems believe that the stem will eventually debond from the cement. As the patient is walking, the stem is moving, rubbing on the cement. If the surface of the stem is rough, cement particles will be generated. These particles will be transferred to the articulation surface and will generate third-body wear. If the stem surface is smooth (polished) the amount of particles generated will be minimized.

Surgeons who use tapered polished stems also believe that the stem should be allowed to subside in the cement mantle. This subsidence is very small (around 1mm-2mm over a few years), and allows the stem to regain a new stability point in the cement mantle. Typically these stems do not have a collar or other surface features (roughened surface, cement grooves, etc.), because that would interfere with subsidence. As the cement creeps (slowly deforms), the stem will gradually subside and maintain the same level of stresses as before.