Which surgical position involves flexing the hips and knees while the patient is on their back?

The lithotomy surgical position is characterized by the patient lying on their back with hips and knees flexed. This position is commonly used for procedures involving the pelvis and lower abdomen, including gynecological surgeries and urological procedures. By flexing the hips and knees, the lithotomy position provides optimal access to the surgical site without hindering the surgeon's visibility or access.

The supine position, while the patient is also on their back, does not involve the flexing of hips and knees, as the legs are typically extended. The prone position involves the patient lying face down, which is not applicable in this context. Fowler's position features the patient sitting up at an angle, again not aligning with the description provided. Thus, the correct identification of the lithotomy position is essential for understanding appropriate patient positioning in surgical practice.