<Page>
EXHIBIT 3.13
[SEAL]
CERTIFICATION OF AMENDMENT
OF
ARTICLES OF INCORPORATION
OF
ANAMED CORPORATION,
A NEVADA CORPORATION
[SEAL]
James Weigl and Burrell E. Clawson certify that:
1. They are the duly elected and acting President and Secretary,
respectively, of Anamed Corporation, a Nevada corporation.
2. ARTICLE 1 of the Articles of Incorporation of the corporation shall
be amended in its entirety to read as follows:
"ARTICLE 1: The name of the corporation shall be ANAMED INTERNATIONAL,
INC."
3. ARTICLE 4 of the Articles of Incorporation of the corporation shall
be amended in its entirety to read as follows:
"ARTICLE 4: The total number of shares of stock which the
corporation is authorized to have outstanding is 400,000
shares Common Stock with no par value.
Upon the filing in the Office of the Secretary of State
of Nevada of this Certificate of Amendment whereby
Article 4 is amended, each issued and outstanding share
of Common Stock shall thereby and thereupon be
reclassified as and changed into one hundred (100)
shares of Common Stock. Each holder of Common Stock
shall be entitled to receive such number of whole shares
and fractional shares, if any, of Common Stock resulting
from such stock split."
4. The foregoing amendments have been approved by the Board of
Directors of the corporation by an Action by Unanimous Written Consent of
Directors, effective as of March 31, 1995.
5. The number of shares of the corporation outstanding and entitled to
vote on the foregoing amendments are 1,000; said amendments have been consented
to and approved by more than 80% of the outstanding shares entitled to vote
thereon.
<Page>
IN WITNESS WHEREOF, the undersigned have executed this Certificate on
March 31, 1995.
/s/ James Weigl
----------------------------------
James Weigl, President
/s/ Burrell E. Clawson
----------------------------------
Burrell E. Clawson, Secretary
2
<Page>
STATE OF CALIFORNIA )
)
COUNTY OF ORANGE )
On March 31, 1995, before me, W. JEAN NEWFIELD, a Notary Public in and
for said State, personally appeared James Weigl, personally known to me (or
proved to me on the basis of satisfactory evidence) to be the person whose name
is subscribed to the within instrument and acknowledged to me that he executed
the same in his authorized capacity, and that by his signature on the instrument
the person, or the entity upon behalf of which the person acted, executed the
instrument.
WITNESS my hand and official seal.
Signature: /s/ W. Jean Newfield
----------------------------------
[SEAL]
STATE OF CALIFORNIA )
)
COUNTY OF ORANGE )
On March 31, 1995, before me, W. JEAN NEWFIELD, a Notary Public in and
for said State, personally appeared Burrell E. Clawson, personally known to me
(or proved to me on the basis of satisfactory evidence) to be the person whose
name is subscribed to the within instrument and acknowledged to me that he
executed the same in his authorized capacity, and that by his signature on the
instrument the person, or the entity upon behalf of which the person acted,
executed the instrument.
WITNESS my hand and official seal.
Signature: /s/ W. Jean Newfield
----------------------------------
[SEAL]
[SEAL]
3