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 * NELSON GLEN D   2. Issuer Name and Ticker or Trading Symbol CARDIOVASCULAR SYSTEMS INC [NONE] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) __X__ Other (specify below) 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 Common Stock               60,000 D   Common Stock               151,167 I Held by LLC (1)

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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

Stock Option (right to buy)

$ 6

12/01/2004

11/30/2009

Common Stock

10,000

10,000

D

Stock Option (right to buy)

$ 8

12/01/2005

11/30/2010

Common Stock

15,000

15,000

D

Stock Option (right to buy)

$ 5.71

12/19/2006

12/18/2016

Common Stock

20,000

20,000

D

Stock Option (right to buy)

$ 5.11

10/09/2007

10/08/2017

Common Stock

6,681

6,681

D

Stock Option (right to buy)

$ 7.36

11/13/2007

11/12/2017

Common Stock

23,319

23,319

D

Series A Conv Preferred Stock

(2)

(2)

(2)

Common Stock

132,042

132,042

I

Held by LLC (1)

Series A-1 Conv Preferred Stock

(3)

(3)

(3)

Common Stock

43,235

43,235

I

Held by LLC (1)

Series B Conv Preferred Stock

(4)

(4)

(4)

Common Stock

54,585

54,585

I

Held by LLC (1)

Warrant

$ 5.71

07/19/2006

07/19/2011

Series A Conv Preferred Stock

18,750

18,750

I

Held by LLC (1)

Warrant

$ 6

09/12/2008

09/12/2013

Common Stock

83,333

83,333

I

Held by LLC (1)

Warrant

$ 5.71

02/25/2009

J(5)

87,416

02/25/2009

02/24/2014

Common Stock

87,416

$ 0

87,416

I

Held by LLC (1)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
NELSON GLEN D 651 CAMPUS DRIVE ST. PAUL, MN 55112	X			Mbr of 13(d) grp owng >10%

Signatures

/s/ Carlye S. Landin as Attorney-in-Fact for Glen D. Nelson 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)	Shares are held by GDN Holdings, LLC, of which Dr. Nelson is the sole owner.
(2)	Each share of Series A convertible preferred stock is convertible at any time, at the holder's election, into 1.01 shares of common stock and has no expiration date.
(3)	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.
(4)	Each share of Series B convertible preferred stock is convertible at any time, at the holder's election, into 1.01 shares of common stock and has no expiration date.
(5)	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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