Which of the following describes Polarstem stem size configurations?

• A. 0-12 Standard; 2-11 Lateral; 0-6 Valgus
• B. 0-11 Standard; 0-9 Lateral; 0-7 Valgus
• C. 0-11 Standard; 1-11 Lateral; 0-7 Valgus
• D. 0-9 Standard; 2-11 Lateral; 0-5 Valgus

Answer: (C)

Polarstem stem sizing uses separate size ranges for three offset configurations: Standard, Lateral, and Valgus. The correct configuration aligns with the instrument’s designed ranges: Standard can be from 0 up to 11, Lateral starts at 1 and goes to 11, and Valgus can range from 0 to 7. The need for a minimum of 1 for the lateral offset reflects that some lateral offset must be achieved to create the intended lateralization, while valgus is more constrained due to the geometry of the implant and anatomy. The other options show ranges that don’t match these design constraints (for example, starting the lateral range at 0 or extending standard beyond 11), so they aren’t valid configurations.