WASHINGTON, May 22 (Reuters) - Medtronic Spine LLC (MDT.N: Quote, Profile, Research) has agreed to pay $75 million to settle allegations that it caused hospitals to submit false claims to Medicare, the Justice Department said on Thursday. The Justice Department accused Medtronic, formerly known as Kyphon Inc, of marketing a minimally invasive back surgery as a more expensive inpatient treatment rather than an outpatient procedure.