================================================================================
                       SECURITIES AND EXCHANGE COMMISSION,
                             WASHINGTON, D.C. 20549
                                -----------------
                                   SCHEDULE TO
                                 (RULE 14D-100)
            TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
                                 AMENDMENT NO. 20
                                -----------------
                                 CENTERPULSE AG
                       (Name of Subject Company (Issuer))

                              ZIMMER HOLDINGS, INC.
                      (Names of Filing Persons (Offerors))
                                -----------------
              REGISTERED SHARES, NOMINAL VALUE CHF 30.00 PER SHARE
                         (Title of Class of Securities)
                                -----------------
                                 NOT APPLICABLE*
                      (CUSIP Number of Class of Securities)
                                -----------------
                              DAVID C. DVORAK, ESQ.
                              ZIMMER HOLDINGS, INC.
                              345 EAST MAIN STREET
                              WARSAW, INDIANA 46580
                                 (574) 267-6131

                  (Name, Address and Telephone Number of Person
  Authorized to Receive Notices and Communications on Behalf of Filing Persons)

                                   COPIES TO:
                             MORTON A. PIERCE, ESQ.
                            M. ADEL ASLANI-FAR, ESQ.
                              JACK S. BODNER, ESQ.
                              DEWEY BALLANTINE LLP
                           1301 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10019
                                 (212) 259-8000
                                -----------------

*     There is no CUSIP Number assigned to the registered shares. CUSIP No.
      152005104 has been assigned to the American depositary shares of
      Centerpulse AG that are quoted on the New York Stock Exchange under the
      symbol "CEP." CUSIP No. 152005203 has been assigned to the American
      depositary shares of Centerpulse AG that were issued pursuant to a
      restricted American depositary receipt facility and are not publicly
      traded.

[ ]   Check the box if the filing relates solely to preliminary communications
      made before the commencement of a tender offer.

      Check the appropriate boxes below to designate any transactions to which
      the statement relates:

      [X]   third-party tender offer subject to Rule 14d-1.

      [ ]   issuer tender offer subject to Rule 13e-4.

      [ ]   going-private transaction subject to Rule 13e-3.

      [ ]   amendment to Schedule 13D under Rule 13d-2.

      Check the following box if the filing is a final amendment reporting the
      results of the tender offer: [ ]

================================================================================


      This Amendment No. 20 amends and supplements the Tender Offer Statement on
Schedule TO, dated June 19, 2003 (as previously amended or supplemented, the
"Schedule TO"), filed by Zimmer Holdings, Inc., a Delaware corporation
("Zimmer"), relating to the third-party tender offer by Zimmer to exchange 3.68
shares of common stock, par value US$0.01 per share, of Zimmer ("Zimmer Common
Stock") and CHF 120 in cash, for each outstanding registered share, nominal
value CHF 30 per share, of Centerpulse AG, a listed company incorporated in
Switzerland ("Centerpulse"), including registered shares represented by
Centerpulse American depositary shares ("ADSs"), upon the terms and subject to
the conditions set forth in the prospectus (as modified, amended or
supplemented, the "Prospectus"), the related ADS Letter of Transmittal and Form
of Declaration of Acceptance and Assignment (collectively referred to as the
"Offer"), which are attached to the Schedule TO as Exhibits (a)(1), (a)(2) and
(a)(3), respectively. Capitalized terms used but not defined herein have the
meanings assigned to such terms in the Prospectus and in the Schedule TO.

      Zimmer has filed a Registration Statement on Form S-4, of which the
Prospectus is a part, relating to shares of Zimmer Common Stock to be issued to
holders of Centerpulse registered shares (including registered shares
represented by Centerpulse American depositary shares) in the Offer (the
"Registration Statement").

      The information set forth in the entire Registration Statement, including
all schedules, exhibits and annexes thereto, the related ADS Letter of
Transmittal, the related Form of Declaration of Acceptance and Assignment and
any prospectus, prospectus supplement or other supplement thereto related to the
Offer hereafter filed with the Securities and Exchange Commission by Zimmer is
hereby expressly incorporated by reference in answer to Items 1 through 11 of
the Schedule TO.

ITEMS 1 THROUGH 11.

  Items 1 through 11 are hereby amended and supplemented as follows:

      The subsequent offering period (or additional acceptance period) for the
Offer expired at 4:00 p.m., Central European time, 10:00 a.m., New York City
time, on Monday, September 15, 2003.  On September 16, 2003, Zimmer announced
the preliminary final results of the Offer and its offer for all of the
outstanding bearer shares of InCentive Capital AG ("InCentive"), which
beneficially owns 2,237,577 Centerpulse registered shares representing
approximately 18.3% of the issued Centerpulse shares (such offer, the
"InCentive Offer" and, together with the Offer, the "Offers"), pursuant to
Swiss law.  Based on preliminary information provided by Credit Suisse First
Boston and Mellon Investor Services LLC (the Swiss offer manager and the U.S.
exchange agent, respectively, for the Offer), as of the expiration of the
subsequent offering period, an aggregate of 9,006,082 Centerpulse registered
shares and 8,655,097 ADSs, including ADSs subject to guaranteed delivery, were
tendered and not withdrawn in the initial offering period and subsequent
offering period.  Based on information provided by Centerpulse, the foregoing
shares and ADSs represent approximately 80.5% and, together with the
Centerpulse registered shares held by InCentive, 98.8% of the issued
Centerpulse registered shares (including shares represented by ADSs).

      Zimmer will announce the definitive final results of the Offers and the
final results of the mix and match elections on September 19, 2003 in
accordance with Swiss law.

      The exchange of Centerpulse registered shares and ADSs for shares of
Zimmer Common Stock and cash will take place on October 2, 2003.

      Based on the preliminary results of the mix and match elections in the
Offers, holders of Centerpulse registered shares and ADSs who elected to
receive "as many shares of Zimmer Common Stock as possible" are expected to
receive 3.7942 shares of Zimmer Common Stock and CHF 112.86 net in cash for each
tendered registered share and 0.3794 of a share of Zimmer Common Stock and the
U.S. dollar equivalent of CHF 11.29 net in cash for each tendered ADS.  Holders
of Centerpulse registered shares and ADSs who elected to receive "as much cash
as possible" will receive CHF 350.00 net in cash for each tendered registered
share and the U.S. dollar equivalent of CHF 35.00 net in cash for each
tendered ADS.  Holders of Centerpulse registered shares and ADSs who elected to
receive the "standard entitlement" or who did not make any mix and match
elections will receive 3.68 shares of Zimmer Common Stock and CHF 120.00 net in
cash for each tendered registered share and 0.368 of a share of Zimmer Common
Stock and the U.S. dollar equivalent of CHF 12.00 net in cash for each tendered
ADS.

      Shares of Zimmer Common Stock to be issued pursuant to the Offers have
been authorized for listing on the New York Stock Exchange.  Zimmer has applied
for a secondary listing of shares of Zimmer Common Stock on the Swiss Stock
Exchange.  Zimmer expects these shares to begin trading on the Swiss Stock
Exchange immediately following the consummation of the Offers.

      Zimmer intends promptly to initiate the compulsory acquisition process
under Swiss law with respect to both Centerpulse and InCentive.  Under the
Swiss compulsory acquisition process, subject to approval by the relevant Swiss
authorities, each Centerpulse registered share (including shares represented by
ADSs) and each InCentive bearer share that remain outstanding will be cancelled
and converted into the right to receive the consideration offered in the Offer
and the InCentive Offer, respectively.

      On September 16, 2003, Zimmer issued the press release attached to this
Schedule TO as exhibit (a)(43) relating to the foregoing.  The information set
forth in the above-referenced document is specifically incorporated herein by
reference.

ITEM 12. EXHIBITS.

      Item 12 of the Schedule TO is hereby amended by adding the following
exhibit thereto:

(a)(43)      Press Release of Zimmer Holdings, Inc., dated September 16, 2003
             (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
             425 filing made with the Securities and Exchange Commission on
             September 16, 2003).



                                    SIGNATURE

      After due 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.


                                  ZIMMER HOLDINGS, INC.


                                   By:  /s/ J. Raymond Elliott
                                        ----------------------------------------
                                        J. Raymond Elliott
                                        Chairman of the Board,
                                        President and Chief Executive Officer

Date: September 16, 2003



                                  EXHIBIT INDEX



EXHIBIT NO.                       DESCRIPTION
-----------                       -----------
         

(a)(1)      Prospectus, dated June 19, 2003 (incorporated herein by reference to
            Zimmer Holdings, Inc.'s Rule 424(b)(3) filing in connection with
            Registration Statement No. 333-105561 made with the Securities and
            Exchange Commission on June 20, 2003).

(a)(2)      Form of ADS Letter of Transmittal (incorporated herein by reference
            to Exhibit 99.1 of Zimmer Holdings, Inc.'s Registration Statement on
            Form S-4/A, Registration No. 333-105561, filed with the Securities
            and Exchange Commission on June 18, 2003).

(a)(3)      Form of Declaration of Acceptance and Assignment (incorporated
            herein by reference to Exhibit 99.2 of Zimmer Holdings, Inc.'s
            Registration Statement on Form S-4/A, Registration No. 333-105561,
            filed with the Securities and Exchange Commission on June 18, 2003).

(a)(4)      Form of ADS Notice of Guaranteed Delivery (incorporated herein by
            reference to Exhibit 99.3 of Zimmer Holdings, Inc.'s Registration
            Statement on Form S-4/A, Registration No. 333-105561, filed with the
            Securities and Exchange Commission on June 18, 2003).

(a)(5)      Form of Letter to Brokers, Dealers, Commercial Banks, Trust
            Companies and Other Nominees (incorporated herein by reference to
            Exhibit 99.4 of Zimmer Holdings, Inc.'s Registration Statement on
            Form S-4/A, filed with the Securities and Exchange Commission on
            June 18, 2003).

(a)(6)      Form of Letter to Clients for use by Brokers, Dealers, Commercial
            Banks, Trust Companies and Other Nominees (incorporated herein by
            reference to Exhibit 99.5 of Zimmer Holdings Registration Statement
            on Form S-4/A, Registration No. 333-105561, filed with the
            Securities and Exchange Commission on June 18, 2003).

(a)(7)      Guidelines for Certification of Taxpayer Identification Number on
            Substitute Form W-9 (incorporated herein by reference to Exhibit
            99.6 of Zimmer Holdings, Inc.'s Registration Statement on Form
            S-4/A, Registration No. 333-105561, filed with the Securities and
            Exchange Commission on June 18, 2003).

(a)(8)      Swiss Pre-Announcement, dated May 20, 2003, of Zimmer Holdings, Inc.
            with respect to its offer for Centerpulse registered shares
            (including shares represented by Centerpulse American depositary
            shares) (incorporated herein by reference to Zimmer Holdings, Inc.'s
            Rule 425 filing made with the Securities and Exchange Commission on
            May 20, 2003).

(a)(9)      Press Release of Zimmer Holdings, Inc., dated May 20, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on May
            20, 2003).

(a)(10)     Slide Presentation of Zimmer Holdings, Inc., dated May 20, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on May
            20, 2003).

(a)(11)     Published Letter of Zimmer Holdings, Inc., dated May 21, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on May
            21, 2003).

(a)(12)     Press Release of Zimmer Holdings, Inc., dated May 29, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on May
            30, 2003).






                                 EXHIBIT INDEX



EXHIBIT NO.                      DESCRIPTION
-----------                      -----------
         

(a)(13)     Form of Swiss Offer Prospectus (incorporated herein by reference to
            Exhibit 99.9 of Zimmer Holdings, Inc.'s Registration Statement on
            Form S-4/A, Registration No. 333-105561, filed with the Securities
            and Exchange Commission on June 18, 2003).

(a)(14)     Swiss Offer Prospectus Summary, dated June 19, 2003, (incorporated
            herein by reference to Zimmer Holdings, Inc.'s Rule 425 filing made
            with the Securities and Exchange Commission on June 19, 2003).

(a)(15)     Press Release of Zimmer Holdings, Inc., dated June 19, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on June
            19, 2003).

(a)(16)     Press Release by Zimmer Holdings, Inc., dated June 20, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on June
            20, 2003).

(a)(17)     Form of letter to registered holders of Centerpulse shares.*

(a)(18)     Announcement of Zimmer Holdings, Inc., dated July 9, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on July
            9, 2003).

(a)(19)     Press Release of Zimmer Holdings, Inc., dated July 9, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on July
            9, 2003).

(a)(20)     Press Release of Zimmer Holdings, Inc., dated July 16, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on July
            16, 2003).

(a)(21)     Press Release of Zimmer Holdings, Inc., dated July 22, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            July 22, 2003).

(a)(22)     Press Release of Zimmer Holdings, Inc., dated July 23,2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on July
            23,2003).

(a)(23)     Press Release of Zimmer Holdings, Inc., dated July 23, 2003
            (incorporated by herein reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on July
            23, 2003).

(a)(24)     Press Release of Zimmer Holdings, Inc., dated July 25, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s, Rule
            425 filing made with the Securities and Exchange Commission on July
            25, 2003).

(a)(25)     Transcript of Zimmer Holdings, Inc.  Earnings Conference Call held
            on July 24, 2003 (incorporated herein by reference to Zimmer
            Holdings Inc.'s Rule 425 filing made with the Securities and
            Exchange Commission July 25, 2003).






                                 EXHIBIT INDEX



EXHIBIT NO.                      DESCRIPTION
-----------                      -----------
         

(a)(26)     Press Release of Zimmer Holdings, Inc., dated July 30, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on July
            30, 2003).

(a)(27)     Press Release of Zimmer Holdings, Inc., dated August 6, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            August 6, 2003).

(a)(28)     Press Release of Zimmer Holdings, Inc., dated August 6, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            August 6, 2003).

(a)(29)     Correspondence to Zimmer Employees and Sales Force Members, dated
            August 6, 2003 (incorporated herein by reference to Zimmer
            Holdings, Inc.'s Rule 425 filing made with the Securities and
            Exchange Commission on August 7, 2003).

(a)(30)     Press Release of Zimmer Holdings, Inc., dated August 13, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            August 13, 2003).

(a)(31)     Press Release of Zimmer Holdings, Inc., dated August 15, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            August 18, 2003).

(a)(32)     Employee Newsletter of Zimmer Holdings, Inc., distributed August 19,
            2003 (incorporated herein by reference to Zimmer Holdings, Inc.'s
            Rule 425 filing made with the Securities and Exchange Commission on
            August 20, 2003.)

(a)(33)     Press Release of Zimmer Holdings, Inc., dated August 20, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s
            Rule 425 filing made with the Securities and Exchange Commission on
            August 20, 2003).

(a)(34)     Press Release of Zimmer Holdings, Inc., dated August 21, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s
            Rule 425 filing made with the Securities and Exchange Commission on
            August 21, 2003).

(a)(35)     Announcement of Zimmer Holdings, Inc., dated August 22, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            August 22, 2003).

(a)(36)     Press Release of Zimmer Holdings, Inc., dated August 26, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            August 26, 2003).

(a)(37)     Press Release of Zimmer Holdings, Inc., dated August 28, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            August 28, 2003).

(a)(38)     Press Release of Zimmer Holdings, Inc., dated September 2, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            September 2, 2003).

(a)(39)     Announcement of Zimmer Holdings, Inc., dated September 2, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            September 2, 2003).

(a)(40)     Announcement of Zimmer Holdings, Inc., dated September 2, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            September 2, 2003).




         
(a)(41)     Media Release of Zimmer Holdings, Inc., dated September 4, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            September 4, 2003).

(a)(42)     Presentation Materials of Zimmer Holdings, Inc. made available at
            Zimmer Holdings, Inc.'s European Investor Meetings on September 4,
            2003 (incorporated herein by reference to Zimmer Holdings, Inc.'s
            Rule 425 filing made with the Securities and Exchange Commission on
            September 4, 2003).

(a)(43)     Press Release of Zimmer Holdings, Inc., dated September 16, 2003
            (incorporated herein by reference to Zimmer Holdings, Inc.'s Rule
            425 filing made with the Securities and Exchange Commission on
            September 16, 2003)

(b)(1)      $1,350,000,000 Revolving Credit and Term Loan Agreement among Zimmer
            Holdings, Inc., Zimmer, Inc., Zimmer K.K., Zimmer Ltd., the
            borrowing subsidiaries, and lenders named therein, dated as of June
            12, 2003 (incorporated herein by reference to Exhibit 10.27 of
            Zimmer Holdings, Inc.'s Registration Statement on Form S-4/A,
            Registration No. 333-105561, filed with the Securities and Exchange
            Commission on June 13, 2003).

(b)(2)      $400,000,000 364-Day Credit Agreement among Zimmer Holdings, Inc.,
            Zimmer, Inc., the borrowing subsidiaries, and lenders named therein,
            dated as of June 12, 2003 (incorporated herein by reference to
            Exhibit 10.28 of Zimmer Holdings, Inc.'s Registration Statement on
            Form S-4/A, Registration No. 333-105561, filed with the Securities
            and Exchange Commission on June 13, 2003).

(d)(1)      Agreement, dated as of August 31, 2003, by and among Zimmer
            Holdings, Inc. and certain shareholders of Incentive Capital AG
            listed therein.*

(g)         None.

(h)(1)      Tax opinion of Dewey Ballantine LLP (re: U.S. tax matters)
            (incorporated herein by reference to Exhibit 8.1 of Zimmer Holdings,
            Inc.'s Registration Statement on Form S-4/A, Registration No.
            333-105561, filed with the Securities and Exchange Commission on
            June 19, 2003).

(h)(2)      Tax opinion of Pestalozzi Lachenal Patry (re: Swiss tax matters)
            (incorporated herein by reference to Exhibit 8.2 of Zimmer Holdings,
            Inc.'s Registration Statement on Form S-4/A, Registration No.
            333-105561, filed with the Securities and Exchange Commission on
            June 18, 2003).

(h)(3)      Tax opinion of Bird & Bird (re: U.K. tax matters) (incorporated
            herein by reference to Exhibit 8.3 of Zimmer Holdings, Inc.'s
            Registration Statement on Form S-4/A, Registration No. 333-105561,
            filed with the Securities and Exchange Commission on June 18, 2003).


* Previously filed.