EXHIBIT 10.33




 
                        AMENDMENT TO EMPLOYMENT AGREEMENT


                  THIS AMENDMENT TO EMPLOYMENT  AGREEMENT (this  "Amendment") is
made as of this  1st day of  October,  1998,  by and  between  Exogen,  Inc.,  a
Delaware corporation (the "Company") and Patrick A. McBrayer (the "Executive").

                              W I T N E S S E T H:

                  WHEREAS,  the  Company  and the  Executive  entered  into that
certain Employment Agreement dated as of March 1, 1997 (the "Agreement").

                  WHEREAS,  the  Company and the  Executive  desire to amend the
Agreement, as provided herein.

                  NOW,  THEREFORE,  in  consideration  of the  employment of the
Executive by the Company,  the Company and the  Executive,  each intending to be
legally bound hereby, covenant and agree as follows:

                  The Agreement, effective on the date hereof, is hereby amended
as follows:

                  Section 1.        Amendments to Agreement.

                  a.  Section  4(a)  of the  Agreement  is  hereby  deleted  and
replaced in its entirety with the following:

                           "1.  Base  Compensation.   During  the  term  of  the
         Agreement, the Company shall pay to Executive base monthly compensation
         of Nineteen  Thousand  Five  Hundred  Eighty-Three  and 33/100  dollars
         ($19,583.33),  less all required withholdings.  Base compensation shall
         be  subject  to review by the  Compensation  Committee  of the Board of
         Directors  during  the  second  and  third  years  of the  term  of the
         Agreement; provided that base compensation shall never be reduced below
         the base compensation applicable to the first year."

                  Section 2.        Reference to and Effect on the Agreement.

                  a. Upon the  effectiveness  of Section 1 hereof,  on and after
the  date  hereof,   each  reference  in  the  Agreement  to  "this  Agreement,"
"hereunder,"  "hereof,"  "herein" or words of like  import,  shall mean and be a
reference to the Agreement, as amended hereby.

                  b. Except as specifically  amended above,  the Agreement shall
remain in full force and effect and is hereby ratified and confirmed.

                  c. The Agreement,  as modified by this Amendment,  constitutes
the entire  understanding  among the parties with respect to the subject  matter
thereof,   and  supersedes  any  prior  understanding  and/or  written  or  oral
agreements between them.
<PAGE>
                  Section 3.        Governing Law.

                  This  Amendment  shall  be  governed  by,  and  construed  and
enforced in accordance with, the laws of the State of New Jersey.

                  Section 4.        Headings.

                  Section  headings in this  Amendment  are included  herein for
convenience  of reference only and shall not constitute a part of this Amendment
for any other purpose.

                  IN WITNESS  WHEREOF,  the parties  hereto have  executed  this
Amendment as of the date first above written.


                          EXOGEN, INC.


                          By:          /s/ John P. Ryaby
                                       -----------------
                          Name:        John P. Ryaby
                          Title:       Chairman of the Board
                          Address:     10 Constitution Avenue
                                       P.O. Box 6860
                                       Piscataway, NJ 08855


                           EXECUTIVE:


                           By:          /s/ Patrick A. McBrayer
                                        -----------------------
                           Name:        Patrick A. McBrayer
                           Title:       President and Chief Executive Officer
                           Address:     1522 Stapler Drive
                                        Yardley, PA 19067