IP Law Daily, PATENT—Fed. Cir.: Spinal implant patent infringement claim was based on an invalid patent, (Jun 5, 2026)

By Linda O’Brien, J.D., LL.M.

Intrinsic evidence was persuasive that a medical technology company’s construction of the term “complementary with one another” as including mirrored angles was correct.

The Patent Trial & Appeal Board erred in narrowly construing the claim term “complementary with one another” in entering a judgment that a spinal implant patent owned by a medical device manufacturer was not unpatentable, the U.S. Court of Appeals for the Federal Circuit has ruled in a nonprecedential disposition. Due to the improper claim construction, the manufacturer’s patent was based on an invalid patent. Thus, the Board judgment was reversed (Life Spine, Inc. v. Globus Medical, Inc., No. 24-2167 (Fed. Cir. Jun. 4, 2026)).

Globus Medical, Inc., a developer and manufacturer of musculoskeletal devices, owns U.S. Patent No. 8,845,731 ((“the ’731 patent”), titled “Expandable Fusion Device and Method of Installation Thereof.” The patent is directed to an implant that may be placed between a patient’s vertebrae in spinal fusion surgeries by ensuring the vertebrae are properly spaced apart before they are set in place. To accomplish expandability, the implant has two endplates between which are two sets of “ramped portions” or wedges that “are complementary with one another,” a feature that is claimed in the patent.

In 2021, Globus filed suit against Life Spine, Inc., a medical technology company based in Illinois, alleging that its ProLift® line of products infringed Globus patents. Life Spine challenged the patentability of several of the patents. In an inter partes review, the U.S. Patent Trial & Appeal Board held in a final written decision that claims 10-14 of Globus’ ’731 patent not unpatentable. Life Spine appealed the decision.

Claim construction. The Board wrongly interpreted language in the ’731 patent requiring two ramped portions of the expandable spinal implant to be “complementary with one another,” the court found. Life Spine had proposed that the plain and ordinary meaning of the term was broad enough to “encompass ramps having angles that mirror each other,’ which its expert explained meant that when placed over one another, the two ramps “would yield the same angle relative to the common plane between them” and interact in a generally identical, symmetrical way.” Globus agreed with the preliminary construction proposed by the Board, which required the first ramped portion of the first endplate and second ramped portion of the second endplate to “complete one another.”

Claim language is not considered in insolation. Instead, the specification of the ’731 patent was highly relevant and provided strong support for Life Spine’s construction, the court explained. As one of ordinary skill in the art would understand, the specification’s lone use of “complementary” related to the artificial surfaces and not the ramped portions of the upper and lower endplates. More instructive was that the patent discloses, in words and figures, an embodiment showing the first ramped portion of the first endplate and second ramped portion of the second endplate having mirrored angles, that would not be within the scope of the claims under Globus’ construction.

Additional support for Life Spine’s construction was found in the prosecution history of the ’731 patent. Throughout the prosecution of the patent, the examiner viewed the claims’ use of “complementary with one another” as including mirrored angles and not as being limited to “ramped portions that complete one another.” Notably, during prosecution, Globus explicitly directed the examiner to the embodiment as illustrative of the “complementary” ramped portions of the claims, the court noted.

Consideration of the claim language, specification, and prosecution history of the ’731 patent was persuasive that a person of ordinary skill in the art would understand the scope of “complementary with one another” to include ramps having angles mirroring each other. Since it was undisputed that the claims of the patent were obvious under this construction, the decision of the Board must be reversed, the court concluded.

The Case is No. 24-2167.

Judge: Stark, L.

Attorneys: James M. Glass (Quinn Emanuel Urquhart & Sullivan) for Life Spine, Inc. Stephen D. Zinda (Cabello Hall Zinda PLLC) for Globus Medical, Inc.

Companies: Life Spine, Inc.; Globus Medical, Inc.

Cases: Patent FedCirNews