The Company is party to revenue share agreements with certain past and present members of its scientific advisory board under which these advisors agreed to participate on its scientific advisory board and to assist with the development of the Company’s personalized implant products and related intellectual property. These agreements provide that the Company will pay the advisor a specified percentage of the Company’s net revenue, ranging from 0.1% to 1.33%, with respect to the Company’s products on which the advisor made a technical contribution or, in some cases, which the Company covered by a claim of one of its patents on which the advisor is a named inventor. The specific percentage is determined by reference to product classifications set forth in the

agreement and may be tiered based on the level of net revenue collected by the Company on such product sales. The Company’s payment obligations under these agreements typically expire a fixed number of years after expiration or termination of the agreement, but in some cases expire on a product-by-product basis or expiration of the last to expire of the Company’s patents where the advisor is a named inventor that has claims covering the applicable product.

The Company incurred aggregate revenue share expense including all amounts payable under the Company’s scientific advisory board revenue share agreements of $1.6 million during the year ended December 31, 2020, representing 2.7% of product revenue and $2.0 million during the year ended December 31, 2019, representing 2.6% of product revenue. Revenue share expense is included in research and development.

In the ordinary course of business, the Company is a party to certain non-cancellable contractual obligations typically related to product royalty. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated.

The following table summarizes the Company's contractual obligations as of the year ended December 31, 2020 (in thousands):


	Payment Due by Period
	Total		Less than 1 year		Years 1 to 3		Years 3 to 5		After 5 years


Contractual Obligations (1)(2)	$	1,108	$	179	$	329	$	300	$	300

(2) This table does not include: (a) revenue share obligations to past and present members of our scientific advisory board, as the amounts of such payments are not known with certainty; and (b) contracts that are entered into in the ordinary course of business that are not material in the aggregate in any period presented above. See "Note H—Revenue share agreements" for a description of our revenue share arrangements.

In the ordinary course of the Company's business, the Company is subject to routine risk of litigation, claims and administrative proceedings on a variety of matters, including patent infringement, product liability, securities-related claims, and other claims in the United States and in other countries where the Company sells its products.

On August 15, 2019, the Company filed a lawsuit against Zimmer Biomet Holdings, Inc. and Zimmer, Inc., or “Zimmer Biomet,” in the United States District Court for the District of Delaware seeking damages for Zimmer Biomet's infringement of certain of the Company’s patents related to patient-specific instrument and implant systems. The complaint alleged that Zimmer Biomet’s multiple lines of patient-specific instruments, as well as the implant components used in conjunction with them, infringe four of the Company’s patents. The accused product lines included Zimmer Biomet's patient-specific instrument and implant systems for knee, shoulder, and hip replacement procedures.

On November 5, 2019, Zimmer Biomet filed a lawsuit against the Company in the United States District Court for the District of Delaware, alleging that the Company infringed five patents owned by Zimmer Biomet. Zimmer Biomet alleged that the Company’s iTotal CR and iTotal PS products infringed all five asserted patents, that the Company’s iDuo product infringed three of the asserted patents, and that the Company’s iUni product infringed two of the asserted patents. On January 13, 2020, Zimmer Biomet filed a motion to dismiss the Company’s complaint, and the Company filed its answer to Zimmer Biomet’s complaint, denying that the Company’s products infringed Zimmer Biomet’s asserted patents. The Company’s answer also alleged that Zimmer Biomet’s asserted patents were invalid.

On May 22, 2020, the Company entered into a Settlement and License Agreement, with Zimmer Biomet, Zimmer US, Inc. and Biomet Manufacturing, LLC, or collectively, Zimmer Biomet, pursuant to which the parties agreed to terms for resolving then existing patent disputes. Under the Settlement and License Agreement, the Company and Zimmer Biomet agreed to dismiss both outstanding patent infringement lawsuits between the parties,

the Company granted to Zimmer Biomet a royalty-free, non-exclusive, worldwide license to certain of the Company's patents for Zimmer Biomet’s patient-specific instrumentation used with off-the-shelf knee, hip, and shoulder implants, and Zimmer Biomet granted to the Company a fully paid-up, royalty-free, non-exclusive, worldwide license to certain Zimmer Biomet patents for the Company's implants and patient-specific instruments for the knee. Under the agreement, Zimmer Biomet was required to pay the Company a total of $9.6 million in installments through January 15, 2021, and all such payments were made and received by such date. No payment was due from the Company to Zimmer Biomet under the agreement.

On August 29, 2019, the Company filed a lawsuit against Medacta USA, Inc. in the United States District Court for the District of Delaware. The Company amended its complaint on December 23, 2019, and again on October 14, 2020, adding Medacta International SA (Medacta USA, Inc.’s parent company) as a defendant (Medacta USA, Inc. and Medacta International SA are referred to, together, as “Medacta”). The Company is

seeking damages for Medacta’s infringement of certain of the Company’s patents related to patient-specific instrument and implant systems, alleging that Medacta’s multiple lines of patient-specific instruments, as well as the implant components used in conjunction with them, infringe four of the Company’s patents. The accused product lines include Medacta patient-specific instrument and implant systems for knee and shoulder replacement procedures. On January 6, 2020, Medacta filed its answer to the Company's original complaint, denying that its patient-specific instrument and implant systems infringe the patents asserted by the Company. Medacta’s answer also alleges the affirmative defense that the Company's asserted patents are invalid. The Company expects that Medacta will similarly respond to our amended complaint. Discovery in the lawsuit has commenced and is ongoing.

On March 20, 2020, Osteoplastics LLC ("Osteoplastics"), filed a lawsuit against the Company in the United States District Court for the District of Delaware, and Osteoplastics amended its complaint on April 2, 2020. Osteoplastics alleges that the Company’s proprietary software, including the Company’s iFit software platform, and the Company’s use of its proprietary software for designing and manufacturing medical devices, including implants, infringes seven patents owned by Osteoplastics. On June 15, 2020, the Company filed a motion to dismiss Osteoplastics’ complaint, and on October 21, 2020, the court denied the motion to dismiss. On November 2, 2020, the Company filed its answer to the amended complaint, denying that it infringes the patents asserted by Osteoplastics. The Company’s answer also alleges the affirmative defense that Osteoplastics’ asserted patents are invalid. Discovery in the lawsuit has commenced.

On April 24, 2020, the Company filed a lawsuit against Wright Medical Technology, Inc. and Tornier, Inc. (together, “Wright Medical”) in the United States District Court for the District of Delaware. The Company is seeking damages for Wright Medical’s infringement of certain of the Company's patents related to patient-specific instrument and implant systems. The complaint alleges that Wright Medical’s multiple lines of patient-specific shoulder instruments, as well as the implant components used in conjunction with them, infringe four of the Company’s patents. The accused product lines include Wright Medical’s Tornier Blueprint™ 3D Planning + PSI shoulder replacement systems. On December 14, 2020, Wright Medical filed its answer to the amended complaint, denying that its patient-specific instrument and implant systems infringe the patents asserted by the Company. Wright Medical’s answer also alleges the affirmative defense that the Company’s asserted patents are invalid. Discovery in the lawsuit has commenced.

On May 8, 2020, the Company and an individual plaintiff filed a lawsuit against Aetna, Inc. and Aetna Life Insurance Company (together, “Aetna”) in the United States District Court for the District of Massachusetts seeking damages for Aetna’s improper denial of coverage for personalized knee implants under its health plans and the ones it administers. The Company amended its complaint on August 13, 2020, alleging that Aetna has violated its duties under state and federal law, including the Employee Retirement Income Security Act. On August 27, 2020, Aetna filed a motion to dismiss the amended complaint. The court has not yet ruled on the motion.

Adverse outcomes of these lawsuits could have a material adverse effect on the Company's business, financial condition or results of operations. The Company is presently unable to predict the outcome of these lawsuits or to reasonably estimate a range of potential losses, if any, related to the lawsuits.

In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnifications. The Company’s exposure under these