United States Court of Appeals For the Seventh Circuit ____________________ No. 21‐1649 LIFE SPINE, INC., Plaintiff‐Appellee, v. AEGIS SPINE, INC., Defendant‐Appellant. ____________________

Appeal from the United States District Court for the Northern District of Illinois, Eastern Division. No. 19‐cv‐7092 — Young B. Kim, Magistrate Judge. ____________________

ARGUED JULY 21, 2021 — DECIDED AUGUST 9, 2021 ____________________

Before SCUDDER, ST. EVE, and KIRSCH, Circuit Judges. ST. EVE, Circuit Judge. This trade secret case arises from a short‐lived business relationship between two companies that sell spinal implant devices. Life Spine, Inc. makes and sells a spinal implant device called the ProLift Expandable Spacer System. Aegis Spine, Inc. contracted with Life Spine to distrib‐ ute the ProLift to hospitals and surgeons. In the distribution agreement, Aegis promised to protect Life Spine’s confiden‐ tial information, act as a fiduciary for Life Spine’s property, 2 No. 21‐1649 and refrain from reverse engineering the ProLift. Despite these promises, Aegis funneled information about the ProLift to its parent company, L&K Biomed, Inc., to help L&K de‐ velop a competing spinal implant device. Shortly after L&K’s competing product hit the market, Life Spine sued Aegis for trade secret misappropriation and breach of the distribution agreement. Following a nine‐day evidentiary hearing, the dis‐ trict court granted Life Spine’s motion for a preliminary in‐ junction barring Aegis and its business partners from market‐ ing the competing product. Aegis now appeals. It submits that the district court’s in‐ junction rests on a flawed legal conclusion—namely, that a company can have trade secret protection in a device that it publicly discloses through patents, displays, and sales. We see the issue differently, however. As a legal matter, we do not dispute—nor does Life Spine—that information in the public domain cannot be a trade secret. But the issue here is factual: Did Life Spine publicly disclose the specific information that it seeks to protect by patenting, displaying, and selling the ProLift? The district court found that the answer was no, and Aegis must show that its finding was clear error. It has not done so. Finding no basis to upset the district court’s meticu‐ lous analysis, we affirm. I. Background A. Factual Background Plaintiff Life Spine is an Illinois company that makes and sells surgically implanted medical devices that treat spine dis‐ orders. Its best‐selling device is the ProLift—an expandable spinal implant that treats degenerative disc disease. The Pro‐ Lift consists of an implant, or “cage,” and an installer. The No. 21‐1649 3 cage has five main components, shown in the drawing below: an upper endplate, a lower endplate, a nose ramp, a base ramp, and an expansion screw. Dovetail‐shaped grooves con‐ nect the different components. The installer is used to insert the cage into a patient’s spine and expand it to restore spinal disc height. ProLift cage (exploded)

Expandable cages are intricate devices with many small component parts. Precise engineering is necessary to ensure that they can withstand decades of intense spinal pressure. Life Spine spent more than three years designing and devel‐ oping the ProLift. To do so, it studied publicly available infor‐ mation about other expandable cages, including patents, and went through an exhaustive trial‐and‐error process. During the trial‐and‐error process, Life Spine repeatedly redesigned the device, sometimes by adjusting the size of its comp