A medical clamp, in particular a spinal clamp, includes two clamp limbs connected to a grip part. The grip part executes a clamping movement of the clamp limbs and the clamp limbs are connected to the grip part in a releasable manner. The clamp permits particularly safe, minimally invasive percutaneous interventions, especially in the area of the spinal column. A device for using a medical clamp for providing a reference position for a positioning system for percutaneous interventions and a method for determining a reference position for a positioning system for percutaneous interventions, are also provided.