Exhibit 10.4

FIRST AMENDMENT TO EMPLOYMENT AGREEMENT

THIS FIRST
AMENDMENT TO EMPLOYMENT AGREEMENT (this Amendment) is made effective as of
April 13, 2010 (the Effective Date), by and between Ivan Delevic (Employee)
and MAKO Surgical Corp. (Company).

WHEREAS,
Employee and Company have entered into that certain Employment Agreement,
effective as of April 27, 2010 (the Agreement); and

WHEREAS,
Employee and Company desire to amend the Agreement to correct a scriveners error
and provide additional clarification with respect to Employees relocation
package;

THEREFORE,
in consideration of the mutual covenants, agreements, representations and
warranties contained in the Agreement and this Amendment, the parties hereby
agree as follows:

1.        In order
to correct a scriveners error, clause (i) of the last sentence of Section 2(e)
of the Agreement is hereby amended to provide that the maximum aggregate Gross
Payments (including the gross amounts of the Net Payments) to be made by the
Company to Employee under all of the Relocation Allowance, the Travel
Allowance, the Housing Allowance, and the Closing Allowance shall be One
Hundred Twenty Eight Thousand Five Hundred Dollars ($128,500).

2.        Section
2(e) of the Agreement is hereby amended to insert the following at end of such
section:

Notwithstanding
the foregoing, the parties agree that at the sole discretion of the Companys
Chief Financial Officer, any amount available under each of the four allowances
(i.e. Relocation Allowance, the Travel Allowance, the Housing Allowance, and
the Closing Allowance) may be applied toward any one or more of the remaining
three allowances subject in all cases to the maximum aggregate Gross Payment of
One Hundred Twenty Eight Thousand Five Hundred Dollars ($128,500).

3.        Unless
otherwise defined herein, capitalized terms shall have the same meaning as
described in the Agreement.

4.        Except as
expressly provided herein, all terms and conditions set forth in the Agreement
to which this Amendment applies, shall remain in full force and effect. In the
event of a conflict between this Amendment and the Agreement, this Amendment
shall be controlling.

5.        This
Amendment may be executed in counterparts, each of which are deemed to be
original, but both of which together constitute one and the same instrument.
Copies of signatures sent by facsimile transmission are deemed to be originals
for purposes of execution and proof of this Amendment.

* * * * *

|                                           |  
|------------------------------------------ | -
|First
 Amendment to Agreement  I. Delevic | 1

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IN WITNESS
WHEREOF, the parties have duly executed this Amendment to be effective as of
the day and year first above written.

|                     |                                      |        |                 |                 | 
|-------------------- | ------------------------------------ | ------ | --------------- | --------------- | 
|/s/ Ivan
 Delevic    |                                      | Dated: | April 27,
 2010
|Ivan Delevic         |                                      |        |                
|                     |                                      |        |                
|MAKO
 SURGICAL CORP. |                                      |        |                
|                     |                                      |        |                
|By:                  | /s/ Maurice
 R. Ferré                |        | Dated:          | April 27,
 2010
|                     | Dr. Maurice
 R. Ferré                |        |                 |                
|                     | President
 & Chief Executive Officer |        |                 |                

|                                           |  
|------------------------------------------ | -
|First
 Amendment to Agreement  I. Delevic | 2

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