BELGRADE, MT, Jan. 11, 2019 (GLOBE NEWSWIRE) — Xtant Medical Holdings, Inc. (NYSE American: XTNT), a global medical technology company focused on surgical solutions for the treatment of spinal disorders, announced today the appointment of Ronald Berlin as Vice President & Chief Operations Officer, effective January 1, 2019. Mr. Berlin will report to Michael Mainelli, Xtant’s Interim …