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Stavros G. Vizirgianakis

Chair of the Board at Xtant Medical Holdings
Board

About Stavros G. Vizirgianakis

Stavros G. Vizirgianakis, 54, is an independent Chair of the Board at Xtant Medical (XTNT), serving since August 2022 when he joined the Board in connection with a private placement; his background includes senior leadership in medical devices (ex-CEO of Misonix) and commercial/operations roles at Tyco Healthcare and U.S. Surgical, with a Degree in Commerce from the University of South Africa . He previously held director nomination rights as the lead investor in the 2022 private placement (rights terminated October 7, 2024), and currently leads the Board while remaining independent under NYSE American standards .

Past Roles

OrganizationRoleTenureCommittees/Impact
Misonix, Inc.President & CEOSept 2016 – Oct 2021Led company through acquisition by Bioventus in 2021
Ascendis Health (Ascendis Medical)Managing DirectorJan 2014 – Jul 2016Oversaw medical division after co-founding Surgical Innovations (later part of Ascendis)
Tyco Healthcare (South Africa)General ManagerPrior to 2006General management in South Africa market
U.S. Surgical CorporationDirector of Sales, Sub-Saharan AfricaPrior to Tyco roleRegional sales leadership

External Roles

OrganizationRoleStatusNotes
Apyx Medical Corporation (NASDAQ: APYX)Chair of the BoardCurrentAdvanced energy tech company
Medinotec, Inc. (OTCQX: MDNC)DirectorCurrentMedical device company
Bioventus Inc.DirectorFormerPrior public board experience
Tenaxis Medical, Inc.DirectorFormerPrior board experience

Board Governance

  • Leadership: Independent Chair of the Board since August 2022; CEO (Sean Browne) is separate, providing balanced oversight and governance .
  • Independence: Board determined Mr. Vizirgianakis is independent under NYSE American standards .
  • Committee assignments (as of Sept 9, 2025): Chair, Nominating & Corporate Governance Committee; not a member of Audit or Compensation; prior to Aug 1, 2025 he served on Nominating & Corporate Governance while another director chaired .
  • Attendance and engagement: Board met 17 times in 2024; each director attended at least 75% of Board and committee meetings; all directors attended the 2024 annual meeting .
Committee (2024)Meetings Held (2024)Mr. Vizirgianakis Role
Audit5Not a member
Compensation3Not a member
Nominating & Corporate Governance2Member in 2024; Chair as of 2025 (post Aug 1)

Fixed Compensation (Director)

DescriptionAmountNotes
Board Chair annual cash retainer (2024 program)$110,000Chair premium retainers by committee also disclosed (Audit Chair $22,500; Comp Chair $16,250; N&CG Chair $10,000; member fees as listed)
2024 actual fees earned (Mr. Vizirgianakis)$115,000Includes Chair and any committee retainers

Program design: Non-employee directors receive annual cash retainers and initial/annual equity grants; annual equity for 2024 was granted August 15, 2024 .

Performance Compensation (Director Equity)

ItemDetail
2024 Annual Equity (all non-employee directors other than Chair)162,162 RSUs/DSUs each, granted Aug 15, 2024
2024 Additional Chair Equity (Mr. Vizirgianakis)748,648 DSUs granted Aug 15, 2024, reflecting Chair role and time commitment
2024 Stock Awards grant date fair value (Mr. Vizirgianakis)$449,189
Options outstanding as of 12/31/2024 (Mr. Vizirgianakis)42,345 options
Director compensation limits (plan feature)$400k annual cap per non-employee director; $600k for Board Chair/Lead Independent Director
Governance features of planNo repricing without shareholder approval; no tax gross-ups; clawback provisions; no evergreen

Director equity awards are time-based RSUs/DSUs (not performance-conditioned); performance awards discussed in the proxy apply to executives, not directors .

Other Directorships & Interlocks

CompanyRolePotential Interlock/Conflict Considerations
Apyx Medical (APYX)ChairMedtech peer; no disclosed related-party transactions with XTNT
Medinotec (MDNC)DirectorMedtech peer; no disclosed related-party transactions with XTNT

Expertise & Qualifications

  • Public company CEO experience; medical device and orthobiologics domain expertise; sales/marketing; operations/manufacturing; financial/accounting; international; M&A; governance, per Board’s skills matrix .

Equity Ownership

HolderBeneficial Ownership% of Shares OutstandingBreakdown/Notes
Stavros G. Vizirgianakis8,449,102 shares5.9%Includes 5,995,355 common, 966,418 vested DSUs, 42,345 options, 1,444,984 warrants as of Sept 9, 2025
Unvested director equity (at 12/31/2024)748,648 DSUsn/aUnvested and not counted in beneficial ownership unless vesting within 60 days
  • Anti-hedging/anti-pledging: Company practice bars hedging/pledging; “What we don’t do” includes “No pledging of Xtant securities” .
  • Clawback: Company adopted a mandatory clawback policy effective Oct 1, 2023 (executive incentive comp) .

Insider Trades (Form 4)

Transaction DateFiling DateTypeSecurities TransactedPricePost-Transaction OwnershipSource
2025-11-152025-11-18A (Award)553,797 common$0.007,515,570https://www.sec.gov/Archives/edgar/data/1453593/000155983425000006/0001559834-25-000006-index.htm
2024-08-152024-08-19A (Award)505,405 common$0.006,961,773https://www.sec.gov/Archives/edgar/data/1453593/000123580224000071/0001235802-24-000071-index.htm
2024-08-152024-08-19A (Award)243,243 common$0.006,456,368https://www.sec.gov/Archives/edgar/data/1453593/000123580224000071/0001235802-24-000071-index.htm
2023-08-152023-08-17A (Award)217,770 common$0.006,213,125https://www.sec.gov/Archives/edgar/data/1453593/000123580223000094/0001235802-23-000094-index.htm
2023-08-152023-08-17A (Option grant)42,345 options$1.2042,345 optionshttps://www.sec.gov/Archives/edgar/data/1453593/000123580223000094/0001235802-23-000094-index.htm

Pattern: Only awards/grants reported since 2023; no open-market sales disclosed in these filings [above Form 4 URLs].

Director Compensation Mix (2024)

ComponentAmountMix
Cash fees$115,000~20% (of total)
Stock awards (DSU)$449,189~80% (of total)
Total$564,189100%

Values from Director Compensation Table; mix calculated from cited amounts .

Related-Party Exposure and Conflicts

  • Prior nomination rights: As lead investor in the August 2022 private placement, he held director nomination rights and was appointed Chair; these rights terminated on October 7, 2024 .
  • 2025 share sale and registration rights: On April 10, 2025, OrbiMed affiliates sold 73,114,592 XTNT shares to purchasers including funds affiliated with Nantahala and Carol Ann Vizirgianakis (his mother); while XTNT was not party to the stock purchase agreement, the company granted resale registration rights to the purchasers and agreed to customary indemnities and expenses .
  • Board composition influence: Two directors (Jain, Lipschultz) were appointed at Nantahala’s request on August 1, 2025; the company states there is no investor rights agreement with Nantahala on board composition .

Say-on-Pay & Shareholder Signals

  • Say-on-pay support: Over 98% approval at the 2024 Annual Meeting, indicating strong shareholder support for compensation practices .
  • Frequency: Board recommends annual say-on-pay; frequency vote conducted in 2025 as required .

Compensation Committee Process and Controls

  • Independent consultant: Mercer (US) Inc. engaged since August 2023 for executive and director compensation; no other services provided, independence assessed .
  • Plan discipline: No option/SAR repricing without shareholder approval; no evergreen; no tax gross-ups; clawback provisions .

Governance Assessment

  • Positives:

    • Independent Chair with deep medtech operating and M&A experience; separation from CEO role supports oversight .
    • Strong ownership alignment: 5.9% beneficial ownership and equity-heavy director pay (≈80% equity in 2024) align incentives with shareholders .
    • Governance features: No repricing, no tax gross-ups, anti-pledging/hedging practices, and a clawback policy enhance investor protections .
  • Watch items/RED FLAGS:

    • Related-party optics: 2025 secondary sale included his mother among purchasers and company-provided registration rights—though customary, it creates perceived proximity to capital structure actions; monitor any future transactions for preferential treatment .
    • Historical nomination rights: His 2022 investor nomination rights (now terminated) concentrated influence during a transitional period; continuing large stake and Chair role warrant attention to independence-in-fact despite formal independence .
    • Concentrated shareholder influence: Nantahala (48.9%) requested two director appointments in 2025; while no formal agreement exists, this concentration may affect board dynamics and minority holder perceptions .