OMB APPROVAL
	OMB Number: 3235-0145
	Expires: March 31, 2009
	Estimated average burden hours per response ... 10.4

Washington, D.C. 20549

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

141619106

(CUSIP Number)

February 25, 2009

(Date of Event Which Requires Filing of this Statement)

 

 

CUSIP No.		141619106	13G	Page		2		of		9	Pages

CUSIP No.		141619106	13G	Page		3		of		9	Pages

CUSIP No.		141619106	13G	Page		4		of		9	Pages

CUSIP No.		141619106	13G	Page		5		of		9	Pages

CUSIP No.		141619106		Page		6		of		9

Item 1.

(a) Name of Issuer: Cardiovascular Systems, Inc. (f/k/a Replidyne, Inc.) (the “Issuer”).

(b) Address of the Issuer’s Principal Executive Offices: 651 Campus Drive, St. Paul, Minnesota 55112.

Item 2.

(a) Name of Person Filing: This joint statement on Schedule 13G is being filed by James A. Silverman, RRC Management, LLC, RRC Bio Fund, L.P. and Risk Reward Capital Management, Inc., who are collectively referred to as the “Reporting Persons.” Mr. Silverman (the “Manager”) is the manager of RRC Management, LLC (“Capital”), which is the sole general partner of RRC Bio Fund, L.P. (the “Fund”). The Manager is also the president of Risk Reward Capital Management, Inc. (“Risk Reward”), which serves as investment adviser to a number of discretionary accounts. The Reporting Persons have entered into a Joint Filing Agreement, dated as of the date hereof, a copy of which is filed with this Schedule 13G as Exhibit 1 (which is incorporated herein by reference), pursuant to which the Reporting Persons have agreed to file this statement jointly in accordance with the provisions of Rule 13d-1(k) under the Act.

     (b) Address of Principal Business Office: The principal business office of the Reporting Persons with respect to the shares reported hereunder is 217R Concord Avenue, Cambridge, MA 02138.

(c) Citizenship: Capital is a Delaware limited liability company. The Fund is a Delaware limited partnership. Risk Reward is a Delaware corporation. The Manager is a U.S. citizen.

(d) Title and Class of Securities: Common stock, $0.001 par value (“Common Stock”).

(e) CUSIP Number: 141619106.

Item 3.		If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

Not applicable.

Item 4.		Ownership

In the aggregate, the Reporting Persons beneficially own 115,136 shares of the Common Stock of the Issuer, representing approximately 0.8% of such class of securities. The beneficial ownership of each Reporting Person is as follows: (i) the Manager, as president of Risk Reward and as manager of Capital, the sole general partner of the Fund, beneficially owns 115,136 shares of Common Stock of the Issuer, representing approximately 0.8% of such class of securities; (ii) the Fund and Capital each beneficially own 76,564 shares of the Common Stock of the Issuer, representing approximately 0.5% of the class; and (iii) Risk Reward, as investment adviser for a number of discretionary accounts, beneficially owns 38,572 shares of Common Stock of the Issuer held by such discretionary accounts, representing approximately 0.3% of such class. The percentage of the Common Stock beneficially owned by each Reporting Person is based on a total of 13,744,890 shares of Common Stock of the Issuer outstanding as of February 25, 2009, immediately after the business combination disclosed in the Issuer’s Form 8-K dated February 25, 2009 described below.

CUSIP No.		141619106		Page		7		of		9

As disclosed in the Form 8-K of the Issuer dated February 25, 2009, Replidyne, Inc., a Delaware corporation (“Replidyne”), completed its business combination with Cardiovascular Systems, Inc., a Minnesota corporation (“CSI-MN”), in accordance with the terms of the Agreement and Plan of Merger and Reorganization, dated as of November 3, 2008, by and among Replidyne, Responder Merger Sub, Inc., a wholly-owned subsidiary of Replidyne (“Merger Sub”), and CSI-MN (the “Merger Agreement”). Pursuant to the Merger Agreement, Merger Sub merged with and into CSI-MN, with CSI-MN continuing after the merger as the surviving corporation and a wholly owned subsidiary of Replidyne. At the effective time of the merger, Replidyne changed its name to Cardiovascular Systems, Inc. (“Issuer”) and CSI-MN changed its name to CSI Minnesota, Inc. Following the merger of Merger Sub with CSI-MN, CSI-MN (under the new name of CSI Minnesota, Inc.) merged with and into Issuer, with Issuer continuing after the merger as the surviving corporation. As a result of the business combination, in exchange for shares of Replidyne’s common stock held by the Reporting Persons, the Reporting Persons received the number of shares of the Issuer’s Common Stock disclosed on this filing.

The Fund has the power to vote and dispose of the shares of Common Stock beneficially owned by such Fund (as described above). Capital, as the sole general partner of the Fund, has the sole authority to vote and dispose of all of the shares of Common Stock beneficially owned by the Fund (as described above). Risk Reward, as manager of each of the separate discretionary accounts which holds shares of the Issuer’s Common Stock, has the power to vote and dispose of the shares held beneficially by Risk Reward (as described above). The Manager, by virtue of his position as manager of Capital and president of Risk Reward, has the sole authority to vote and dispose of all of the shares of Common Stock reported in this joint statement Schedule 13G.

Item 5.		Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than 5 percent of the class of securities, check the following þ.

Item 6.		Ownership of More than Five Percent on Behalf of Another Person

Not applicable.

Item 7.		Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person

Not applicable.

Item 8.		Identification and Classification of Members of the Group

Not applicable.

Item 9.		Notice of Dissolution of Group

Not applicable.

CUSIP No.		141619106		Page		8		of		9

Item 10.		Certification

By signing below I hereby certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

CUSIP No.		141619106		Page		9		of		9

Signature

     After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Exhibit 1

JOINT FILING AGREEMENT

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree, as of March 10, 2009, that only one statement containing the information required by Schedule 13G, and each amendment thereto, need be filed with respect to the ownership by each of the undersigned of shares of common stock of Cardiovascular Systems, Inc. (f/k/a Replidyne, Inc.) and such statement to which this Joint Filing Agreement is attached as Exhibit 1 is filed on behalf of each of the undersigned. This Agreement expressly supersedes the Joint Filing Agreement dated February 10, 2009 among the certain of the parties hereto with respect to the filing of information required by Schedule 13G in relation to Common Stock of the Issuer.