BELGRADE, Mont., Aug. 24, 2020 (GLOBE NEWSWIRE) — Xtant Medical Holdings, Inc. (NYSE American: XTNT), a global medical technology company focused on surgical solutions for the treatment of spinal disorders, today announced the U.S. commercial launch of the Matriform® Si, a silicated synthetic bone graft strip designed and cleared for spinal fusion procedures.  The Matriform …