The trochanteric fossa is best described as which of the following?

• A. A groove on the calcaneus
• B. A notch near the hip joint
• C. A notch for the femoral head
• D. The hollow depressed area at the trochanter

Answer: (D)

Understanding bone terminology helps here: a fossa means a hollow depression on a bone. The trochanteric fossa is such a hollow on the femur, sitting between the greater and lesser trochanters. It’s a shallow pit on the bone’s surface, known as a depression, and it serves as a site where muscles attach (notably the obturator externus tendon). That’s why describing it as the hollow depressed area at the trochanter is the most accurate.

It wouldn’t be a groove on the calcaneus, since the calcaneus (heel bone) has different surface features. It isn’t a notch near the hip joint, which would imply a rim-indent at a joint boundary rather than a depression between the trochanters. And it isn’t a notch for the femoral head, which would relate to another aspect of the hip joint anatomy rather than this intertrochanteric depression.