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                                  EXHIBIT 10.22



                                LETTER AGREEMENT
                            BETWEEN KENNETH G. HAYES
                              AND THE COMPANY DATED
                                  MAY 15, 1997












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                                  EXHIBIT 10.22





May 15, 1997




Mr. Kenneth G. Hayes, Jr.
5 Jay Lane
Acton, MA  01720

Dear Ken:

After a thorough review of your qualifications, I am pleased to offer you the
position of President, Image Guided Surgery of Sofamor Danek Group, Inc. This
position will report to Bob Compton and assumes you will be available to begin
full-time employment on or before August 1, 1997. The major points of the offer
are outlined in the paragraphs below and reflect the verbal agreement we reached
on May 12.

SALARY

Your bi-weekly salary will be $7,692.30. The salary will remain at this level
unless increased by the Compensation Committee at that committee's annual
review. This review process occurs in the fourth quarter of each year for
compensation changes for the following year.

BONUS

As agreed, you will participate in the Executive Level of the Management Bonus
Program beginning in 1997. Your bonus plan will be consistent with the overall
company program and based upon EVA (economic value added) performance. A minimum
bonus of $100,000 for 1997 will be guaranteed based on a start date of not later
than August 1, 1997.

STOCK OPTIONS

Sofamor Danek Group, Inc., is granting you options on 120,000 shares of Sofamor
Danek Group, Inc., common stock at the closing price on May 12. These options
will be non-qualified options.

The stock will vest one-fifth each year over five years beginning on the first
anniversary date of the grant. The vesting is contingent upon your continued
employment with Sofamor Danek 



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Group, Inc. Details of the option grant will be contained in your Employment
Agreement. All other terms of the options are contained in the Company's Long
Term Incentive Plan.

RELOCATION

Sofamor Danek Group, Inc., will assist you with your relocation to Memphis,
Tennessee, as indicated below:

1.     House Hunting Trip Expenses, Sofamor Danek Group, Inc., will pay and/or
       reimburse you for the cost of your family's house hunting trips from
       Acton to Memphis. This reimbursement will include transportation, car
       rental, lodging, meals, and other reasonable expenses.

2.     Moving Cost. Sofamor Danek Group, Inc., will pay and/or reimburse you for
       the cost of packing, transporting, storing, and unpacking your household
       goods from Acton to Memphis. Sofamor Danek will further pay the cost of
       transporting two automobiles, should that be necessary.

3.     Real Estate Commission. Sofamor Danek Group, Inc., will reimburse you for
       the real estate commission on the sale of your Acton home, not to exceed
       6% of the sale price.

4.     Closing Cost. Sofamor Danek Group, Inc., will reimburse you for any
       closing cost, appraisals, and legal fees associated with the sale of your
       current residence and the purchase of your new home in Memphis.
       This total cost is not to exceed $25,000.

S.     Sale of Massachusetts Home. In the event you are unable to sell your home
       in Massachusetts, Sofamor Danek Group, Inc., will purchase or cause to
       have purchased such house. The purchase price shall be the average of
       three appraisals, provided by mutually agreeable appraisal firms. The
       Company will also pay for the appraisal costs.

6.     Dual Temporary Living Expenses. Sofamor Danek Group, Inc., agrees to pay 
       dual temporary living expenses of $3,000 per month for a maximum of six 
       months.

7.     Payment of Tax Liability, In the event that you incur any additional
       federal or state income tax liability because the relocation expenses are
       treated as income to you, are not deductible and are taxable, Sofamor
       Danek Group, Inc., agrees to pay (a) a dollar amount equal to the tax
       liability, and (b) an amount equal to the tax liability on the dollar
       amount determined under 7(a). The total amount calculated under 7 shall
       be paid by Sofamor Danek Group, Inc., directly to the United States
       Internal Revenue Service and the Massachusetts Department of Revenue, and
       will appear on a form W-2 that Sofamor Danek Group, Inc., will prepare
       and deliver to your as appropriate.

8.     Repayment of Relocation Expenses. You acknowledge and agree that these
       relocation expenses are integral parts of Sofamor Danek Group, Inc.'s
       offer of employment to you and that Sofamor Danek Group, Inc., is
       advancing and/or spending substantial funds to relocate 


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       you and your family to Memphis, Tennessee. In consideration thereof, you
       agree that if you voluntarily leave Sofamor Danek Group, Inc., within two
       (2) years of your employment date, then you agree to repay Sofamor Danek
       Group, Inc., all relocation expenses paid and/or reimbursed under the 
       terms of our offer letter.

As a full-time employee and President, Image Guided Surgery of Sofamor Danek
Group, Inc., you will receive the following benefits:

1.     Medical insurance coverage subject to a 90-day probationary period.
       Should you decide to continue your current medical coverage for the
       90-day probationary period, Sofamor Danek Group, Inc., will reimburse you
       for the medical insurance premiums paid by you during this period.
       Pre-existing medical conditions will be covered by this medical
       insurance.

2.     Life insurance coverage equal to two times your annual salary, subject to
       a 90-day probationary period.

3.     Short-term and long-term disability.

4.     Eligibility for 401(k) Tax Deferred Savings Plan after six (6) months of
       employment.

5.     Eligibility for the Sofamor Danek Group, Inc. Employee Stock Purchase
       plan after six (6) months of employment and per the Plan's enrollment
       requirements.

6.     At least four weeks vacation per year.

7.     Payment or reimbursement for business related club dues or cellular phone
       charges of $300.00 per month.

8.     Spouse travel of $4,000.00 per year.

9.     Subscription reimbursement of $300.00 per year.

You will be an employee at will; either you or Sofamor Danek Group, Inc., may
terminate your employment at any time for any reason subject to the conditions
of your Employment Agreement. Sofamor Danek Group, Inc., reserves the right to
modify or eliminate any benefits, policies, plans or programs at any time for
any reason with or without notice unless otherwise specified in your Employment
Agreement.

Sofamor Danek Group, Inc., will assume responsibility for the handling of any
issue raised by a third party that relates to your taking the position of
President, Image Guided Surgery of Sofamor Danek Group, Inc.

Sofamor Danek Group, Inc.'s Board of Directors, Ron Pickard, Bob Compton and I
are enthusiastic about having you as a senior executive of the Company. Please
signify your



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acceptance of our offer by signing below and returning one original of this
letter to me at your earliest convenience.

Sincerely,

/s/ Jim Gallogly

Jim Gallogly
President, Chief Operating Officer



ACCEPTED BY:



/s/ Kenneth G. Hayes, Jr.                            May 29, 1997
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Kenneth G. Hayes, Jr.                                Date