Exhibit 5.1

                            CHOATE, HALL & STEWART
               A PARTNERSHIP INCLUDING PROFESSIONAL CORPORATIONS
                                EXCHANGE PLACE
                                53 STATE STREET
                       BOSTON, MASSACHUSETTS 02109-2891
                            TELEPHONE (617)248-5000
                            FACSIMILE (617)248-4000
                                TELEX 49615860
 
                                               September 11, 1996

Innovasive Devices, Inc.
734 Forest Street
Marlborough, Massachusetts 01752-3032

Gentlemen:

      This opinion is delivered to you in connection with the registration
statement on Form S-8 (the "Registration Statement") to be filed on or about
September 11, 1996 by Innovasive Devices, Inc. (the "Company") under the 
Securities Act of 1933, as amended, for registration under said Act of 
1,088,425 shares of common stock, $.0001 par value (the "Common Stock"), of 
the Company.

      We are familiar with the Company's Third Restated Articles of
Organization, as amended, its By-Laws, as amended, and its corporate minute
book as well as the Registration Statement.  We have also examined such other
documents, records and certificates and made such further investigation as we
have deemed necessary for the purposes of this opinion.

      Based upon and subject to the foregoing, we are of the opinion that the
shares of Common Stock to be sold by the Company under its 1992 Minivasive
Stock Option Plan, its 1996 Omnibus Stock Option Plan, its 1996 Non-Employee
Directors Stock Option Plan and its 1996 Employee Stock Purchase Plan, each as
in effect on the date hereof, when issued against receipt of the agreed
purchase price therefor, will be legally issued, fully paid and nonassessable.

      We understand that this opinion is to be used in connection with the
Registration Statement and consent to the filing of this opinion as an exhibit
to the Registration Statement.  We further consent to the reference to this
firm in the section entitled "Interests of Named Experts and Counsel" in the
Registration Statement.

                                          Very truly yours,

                                          CHOATE, HALL & STEWART
1-289573