Exhibit 5.1

  Hogan Lovells US LLP Harbor East 100 International Drive Suite 2000 Baltimore, MD 21202 T +1 410 659 2700 F +1 410 659 2701 www.hoganlovells.com

December 21, 2015

Board of Directors

Xtant Medical Holdings, Inc.

664 Cruiser Lane

Belgrade, Montana 59714

Ladies and Gentlemen:

We are acting as counsel to Xtant Medical Holdings, Inc., a Delaware corporation (the “Company”), in connection with its registration statement on Form S-1 (the “Registration Statement”), filed with the Securities and Exchange Commission relating to the registration for offer and sale by the selling securityholders listed in the Registration Statement of (i) up to $68,000,000 in aggregate principal amount of the Company’s 6.00% Convertible Senior Notes due 2021 (the “Debt Securities”), and (ii) up to 21,451,035 shares of common stock, par value $0.000001 per share, of the Company that could be issuable upon conversion of the Debt Securities (the “Common Shares” and together with the Debt Securities, the “Securities”), all of which may be sold from time to time and on a delayed or continuous basis, as set forth in the prospectus which forms a part of the Registration Statement, and as to be set forth in one or more supplements to the prospectus. The Debt Securities were issued under the Indenture, dated as of July 31, 2015 (the “Indenture”), by and between the Company and Wilmington Trust, National Association, as trustee (the “Trustee”). This opinion letter is furnished to you at your request to enable you to fulfill the requirements of Item 601(b)(5) of Regulation S-K, 17 C.F.R. § 229.601(b)(5), in connection with the Registration Statement.

For purposes of this opinion letter, we have examined copies of such agreements, instruments and documents as we have deemed an appropriate basis on which to render the opinions hereinafter expressed. In our examination of the aforesaid documents, we have assumed the genuineness of all signatures, the legal capacity of all natural persons, the accuracy and completeness of all documents submitted to us, the authenticity of all original documents, and the conformity to authentic original documents of all documents submitted to us as copies (including telecopies). As to all matters of fact, we have relied on the representations and statements of fact made in the documents so reviewed, and we have not independently established the facts so relied on. This opinion letter is given, and all statements herein are made, in the context of the foregoing.

For purposes of this opinion letter, we have assumed that (i) at the time of offer and sale of any Securities by the selling securityholders, the Registration Statement will have been declared effective under the Securities Act of 1933, as amended (the “Act”), and no stop order suspending its effectiveness will have been issued and remain in effect; (ii) the Debt Securities have been issued pursuant to the Indenture substantially in the form filed as Exhibit 4.5 to the Registration Statement; and (iii) the Company will remain a Delaware corporation.

Hogan Lovells US LLP is a limited liability partnership registered in the District of Columbia. “Hogan Lovells” is an international legal practice that includes Hogan Lovells US LLP and Hogan Lovells International LLP, with offices in: Alicante Amsterdam Baltimore Beijing Brussels Caracas Colorado Springs Denver Dubai Dusseldorf Frankfurt Hamburg Hanoi Ho Chi Minh City Hong Kong Houston Johannesburg London Los Angeles Luxembourg Madrid Miami Milan Moscow Munich New York Northern Virginia Paris Philadelphia Prague Rio de Janeiro Rome San Francisco São Paulo Shanghai Silicon Valley Singapore Tokyo Ulaanbaatar Warsaw Washington DC Associated offices: Budapest Jakarta Jeddah Riyadh Zagreb. For more information see www.hoganlovells.com

December 21, 2015

Board of Directors

Xtant Medical Holdings, Inc.

To the extent that the obligations of the Company with respect to the Securities may be dependent upon such matters, we assume for purposes of this opinion letter that the Trustee is duly organized, validly existing and in good standing under the laws of its jurisdiction of organization; that the Trustee is duly qualified to engage in the activities contemplated by the Indenture; that the Indenture has been duly authorized, executed and delivered by the Trustee and constitutes the legal, valid and binding obligation of the Trustee, enforceable against the Trustee in accordance with its terms; that the Trustee is in compliance with respect to performance of its obligations under the Indenture, with all applicable laws and regulations; and that the Trustee has the requisite organizational and legal power and authority to perform its obligations under the Indenture.

This opinion letter is based as to matters of law solely on the applicable provisions of the following, as currently in effect: (i) as to the opinions given in paragraphs (a) and (b), the Delaware General Corporation Law, as amended, and (ii) as to the opinion given in paragraph (a), the laws of the State of New York (but not including any laws, statutes, ordinances, administrative decisions, rules or regulations of any political subdivision below the state level). We express no opinion herein as to any other laws, statutes, ordinances, rules or regulations (and in particular, we express no opinion as to any effect that such other laws, statutes, ordinances, rules or regulations may have on the opinions expressed herein).

Based upon, subject to and limited by the foregoing, we are of the opinion that:

(a)    The Debt Securities constitute valid and binding obligations of the Company.

(b)    The Common Shares, if and when issued and delivered upon conversion of the Debt Securities in accordance with the terms of the Debt Securities and the Indenture, and upon due execution and delivery on behalf of the Company of certificates therefor, including global certificates, or the entry of the issuance thereof in the books and records of the Company, as the case may be, will be validly issued, fully paid and nonassessable.

The opinion expressed in paragraph (a) above with respect to the valid and binding nature of obligations may be limited by bankruptcy, insolvency, reorganization, receivership, moratorium or other laws affecting creditors’ rights (including, without limitation, the effect of statutory and other law regarding fraudulent conveyances, fraudulent transfers and preferential transfers) and by the exercise of judicial discretion and the application of principles of equity, good faith, fair dealing, reasonableness, conscionability and materiality (regardless of whether the Securities are considered in a proceeding in equity or at law).

This opinion letter has been prepared for use in connection with the Registration Statement. We assume no obligation to advise you of any changes in the foregoing subsequent to the effective date of the Registration Statement.

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December 21, 2015

Board of Directors

Xtant Medical Holdings, Inc.

We hereby consent to the filing of this opinion letter as Exhibit 5.1 to the Registration Statement and to the reference to this firm under the caption “Legal Matters” in the prospectus constituting a part of the Registration Statement. In giving this consent, we do not thereby admit that we are an “expert” within the meaning of the Act.

Very truly yours,

/s/ HOGAN LOVELLS US LLP

HOGAN LOVELLS US LLP

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