German to English Medical Medical (general) Positioning of patient for surgery.

Source: medical report

Patient had lipomas on back that needed to be surgically removed. "Bauchlagerung des Patienten" was part of set up for the operation. In other words, patient needed to be lying on his stomach in order for operation to be performed on the back.

I'm looking for the technical term for positioning a patient on the stomach for surgery.

Thanks in advance.