Mix the ground beef, salt, onion powder, pepper, and Worcestershire sauce in a medium bowl until well-combined. Divide into 12 portions. Shape the meat mixture into 3-inch patties. Cook several at a time in a 12-inch nonstick skillet over medium heat for 10 to 12 minutes or until thoroughly cooked and internal temperature is 160 degrees, turning half way through, and adding more patties as they shrink slightly. Cook all patties. Mix the sour cream and horseradish in a small bowl. Generously spread on the cut sides of the rolls. Place a burger patty on each bun and garnish as desired.