The 9-year-old star of TLC's "Little People, Big World" was recovering Monday from a head injury caused by a medieval catapult at his Helvetia, Ore., home.

Jacob Roloff, 9, and Mike Detjen, 58, were released Monday from Legacy Emanuel Hospital in Portland, Ore., where they were taken Saturday after a 25-foot-high trebuchet, or catapult, redesigned to hurl pumpkins misfired at the Roloff family farm, the Portland Oregonian reported.

Roloff underwent surgery after the catapult's 2,000-pound concrete counterweight dented his skull while Detjen needed more than 200 stitches, the newspaper said.

"Little People, Big World" features the Roloff family, parents Matt and Amy and 16-year-old Zach -- who are dwarfs -- and Jacob and his two other siblings who are average size.

Matt Roloff told the newspaper he did not know what caused the catapult featured on an episode of "Little People, Big World" to fire as it was being loaded by Jacob and Detjen.