Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Thatcher Robert J
   2. Issuer Name and Ticker or Trading Symbol
CARDIOVASCULAR SYSTEMS INC [NONE] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) __X__ Other (specify below)
Executive VP / Mbr of 13(d) grp owng >10%
(Last)
(First)
(Middle)
651 CAMPUS DRIVE		 3. Date of Earliest Transaction (Month/Day/Year)
02/25/2009
(Street)

ST. PAUL, MN 55112		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Series A-1 Conv Preferred Stock (1)               (1)   (1) Common Stock 12,378   12,378 D  
Stock Option (right to buy) $ 8               (2) 10/16/2010 Common Stock 100,000   100,000 D  
Stock Option (right to buy) $ 5.71               (3) 12/18/2016 Common Stock 12,000   12,000 D  
Stock Option (right to buy) $ 5.71               (4) 04/17/2017 Common Stock 46,000   46,000 D  
Stock Option (right to buy) $ 5.11               (5) 08/06/2017 Common Stock 35,000   35,000 D  
Stock Option (right to buy) $ 7.86               (6) 12/11/2017 Common Stock 50,000   50,000 D  
Warrant $ 5.71 02/25/2009   J(7)   4,707   02/25/2009 02/24/2014 Common Stock 4,707 $ 0 4,707 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Thatcher Robert J
651 CAMPUS DRIVE
ST. PAUL, MN 55112		       Executive VP Mbr of 13(d) grp owng >10%

Signatures

 /s/ Carlye S. Landin as Attorney-in-Fact for Robert J. Thatcher pursuant to Power of Attorney previously filed.   02/25/2009
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Each share of Series A-1 convertible preferred stock is convertible at any time, at the holder's election, into 1.03 shares of common stock and has no expiration date.
(2) Exercisable: 33,333 on 10/17/2006 and 10/17/2007 and 33,334 on 10/17/2008.
(3) Exercisable: 4,000 on 12/19/2007, 12/19/2008 and 12/19/2009.
(4) Exercisable: 15,333 on 4/18/2008 and 4/18/2009 and 15,334 on 4/18/2010.
(5) Exercisable: 11,667 on 8/7/2008 and 8/7/2009 and 11,666 on 8/7/2010.
(6) Exercisable: 25,000 on the first anniversary of the closing of the Company's merger with Replidyne, Inc. and 25,000 on the second anniversary of the merger.
(7) Holders of approximately 68% of the outstanding preferred stock entered into an agreement with the Company whereby effective immediately prior to the effective time of the merger of the Company with Replidyne, Inc., all preferred stock will convert into shares of common stock. The warrants were issued pro rata to each preferred shareholder, based on the percentage of preferred stock held, in consideration for entering into such conversion agreement.

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