Why is uniform cement mantle distribution important around a femoral stem?

• A. Increases cement viscosity
• B. Prevents stress concentration, reduces risk of loosening, ensures even load transfer
• C. Prevents bone remodeling
• D. Improves radiographic visibility

Answer: (B)

Uniform cement mantle distribution around a femoral stem matters because the cement acts as a load-transfer medium between the implant and bone. When the mantle is even, stresses from everyday loads are spread more evenly through the cement and into the surrounding bone, reducing sharp stress concentrations at thin spots. Those stress concentrations are where cement can crack, debond from the bone, or allow micromotion of the stem, all of which raise the risk of aseptic loosening over time. An evenly distributed mantle supports stable fixation by minimizing micromotion at the stem-cement and cement-bone interfaces and promoting more uniform load sharing with the bone. In contrast, a nonuniform mantle creates focal stress risers that can initiate failure of the cement mantle and loosening of the prosthesis. This concept is not about changing cement viscosity, preventing bone remodeling, or improving radiographic visibility.