What is the shape of the Anthology Stem?

• A. Round Stem
• B. Cylindrical Stem
• C. Conical Stem
• D. Flat Taper Stem

Answer: (D)

Stem geometry controls how a stem seats and transfers load, influencing stability and resistance to movement. A flat taper shape combines two key advantages. The taper lets the stem progressively fill the space, guiding correct seating and achieving a snug fit along the length. The flat faces create contact areas that resist rotation and micromotion because they press against flatter surfaces rather than just a circular ring. This combination reduces gaps, distributes forces more evenly, and helps the stem stay oriented correctly under load.

In contrast, a round or cylindrical profile sits in contact around a circular line, which can allow rotation more easily and may not engage flat walls as effectively. A purely conical shape provides taper but without flat facets, it may not offer the same anti-rotation stability. The flat taper design thus best balances secure seating with stable orientation.