Which factor most supports the use of a cementless femoral stem in hip arthroplasty?

• A. Poor bone quality
• B. Good bone quality
• C. High BMI
• D. Advanced age

Answer: (B)

The main idea is that cementless femoral stems achieve fixation through bone ingrowth, so they depend on the bone’s ability to provide a solid, biologically active environment. Good bone quality allows a secure initial press-fit and provides the necessary environment for bone to grow into the porous surface, leading to durable biological fixation over time. When bone quality is good, the stem can be stabilized without cement and will more reliably achieve long-term fixation as the bone integrates with the implant.

In contrast, poor bone quality undermines initial stability, increases micromotion, and reduces the likelihood of successful ingrowth, making cementless fixation less reliable. Age and BMI can influence outcomes but do not directly enable the ingrowth process the way bone quality does.