Alerts and Updates

California Federal Judge Invalidates Spinal Surgery Patents Due to Lack of Objective Boundaries

December 1, 2014

The court found that the patent claims at issue lack the objective boundaries required under Nautilus for meeting the public notice function of patents.

On November 19, 2014, a federal district court in California invalidated claims in two spinal surgery patents, finding the claims indefinite under the U.S. Supreme Court's recent Nautilus[1] standard. In Abdou v. Alphatec Spine, the Southern District of California granted summary judgment of invalidity regarding U.S. Patents 7,951,153 and 8,172,855 asserted by surgeon Dr. Samy Abdou against defendant Alphatec Spine, Inc. ("Alphatec").[2] The court found that the patent claims at issue lack the objective boundaries required under Nautilus for meeting the public notice function of patents. Notably, the court found that the claims would have survived under the old "insolubly ambiguous" test that was the applicable law until June 2014, so this case appears to show the effect of the change in law.[3] The summary judgment ruling in Abdou is likely to be particularly significant because indefiniteness is frequently (and increasingly) presented as a defense in patent litigation.

The Claims at Issue for the Court's Indefiniteness Analysis

Defendant Alphatec contended that independent claims 1, 6, 8, 12 and 21 of U.S. Patent 7,951,153 ("the '153 Patent") and independent claims 6 and 28 of U.S. Patent 8,172,855 ("the '855 Patent") are indefinite.[4] The relevant claim terms in the '153 Patent are: "defined anatomical position," "defined anatomical relationship" and "defined spatial relationship." The relevant claim terms in the '855 Patent are: "attaches on to a first surface" and "in proximity to the first vertebral bone."

The Court's Reasoning for Finding the Claims Indefinite Under the Nautilus Standard

The requirement for "definiteness" in the patent claims at issue is found in 35 U.S.C. § 112 ¶2[5]: "[t]he specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention." The court in Abdou explained that the "reasonable certainty" standard for definiteness under Nautilus requires clarity to "[apprise] the public of what is still open to them" that is more than providing "some meaning" or "some standard" for measuring claim scope, but is less than absolute or mathematical precision.[6] In applying this more rigorous standard, the court accepted certain limitations of claim scope put forth by the patentee's expert but found that the absence of identified, objective boundaries in terms of proximity, distance or location respectively rendered the claim terms at issue fatally indefinite.[7]

By way of example, for the claim phrase "a mount that is positionable at a defined anatomical relationship relative to the target space between the skeletal segments"[8] (emphasis added), the court noted that the phrase had some meaning because the claim required the mount to be positioned to limit movement and the relationship between the mount and the target space to be defined at some point.[9] The court also noted that this term was not insolubly ambiguous.[10] However, it found that because neither the claim nor the specification provided any objective boundaries for guiding a person of skill in the art regarding what the anatomical relationship between the mount and the target space is and is not, the claim was indefinite under the "reasonable certainty" test.[11] In doing so, the court found persuasive the illustration that removing the term would not change the amount of provided guidance as to the scope of the claim.[12]

Additionally, for the claim phrase "a fixation member, having a first segment that attaches onto a proximal segment of the implant insertion member and a second segment that attaches onto a first surface"[13] (emphasis added), the court noted that the claim provided some meaning because it limited the "first surface" to something that both allows for accurate targeting of the claimed surgical site in an operating room and limits movement.[14] The court similarly found that this term was not insolubly ambiguous but was indefinite as not "reasonably certain" because neither the claim including these limitations, nor the specification, informed a person of skill in the art as to which surfaces accessible in the operating room were allowed to be used to the exclusion of other surfaces.[15]

Thus, the court granted the defendant's summary judgment motion of indefiniteness under 35 U.S.C. § 112 ¶2.

Lessons from the Court's Application of the Nautilus Indefiniteness Standard

In the Nautilus case, the U.S. Supreme Court did not apply its new indefiniteness standard, instead setting forth the new standard and leaving to lower courts the task of developing the contours of the case law based on various factual scenarios.[16] Therefore, the court's ruling in Abdou is likely to serve as a valuable data point regarding both the substantive indefiniteness analysis and the procedural posture for indefiniteness challenges in litigation. Key lessons from the Abdou summary judgment ruling include:

  • The Supreme Court in Nautilus noted that its new "reasonable certainty" test for definiteness is more rigorous from a patentee's perspective (i.e., more likely to result in a finding of indefiniteness) than the previous "insolubly ambiguous" test. Now, decisions from lower courts are starting to bear this out. The claims in Abdou would have survived under the old test but were invalidated under the new Nautilus test. The "objective boundaries" analysis will likely feature prominently in coming court decisions.
  • Beyond the general "reasonable certainty" and "objective boundaries" language found in prior court decisions, the decision here offers specific guidance regarding the type of claim language courts are likely to look for in conducting indefiniteness analyses for certain factual scenarios. The court looked for quantitative parameters or a range of distance between relevant claim elements.[17] The court's treatment of the "in proximity" language and "first surface" claim language further offers guidance that future courts are likely to inquire whether the proximity is defined in any specific way and look for a description of what or where the surface should be.[18]
  • In Abdou, the court issued a claim construction ruling in which it construed the terms at issue instead of finding them indefinite as Alphatec had requested. Then, the court granted Alphatec's subsequent motion for summary judgment of indefiniteness, mirroring the procedural scenario in Nautilus. It may become more common for defendants to prevail on indefiniteness following claim construction.
  • In construing the claim terms at issue prior to rendering its finding of indefiniteness, the court examined the claim language and specification to determine whether the patentee defined these terms in the intrinsic record. The court's two-part analysis seems to indicate that if there had been a definition in the specification regarding these terms, then the court may have found the terms definite. As there appears to be a fine line drawn by the Nautilus case between a court importing limitations from the specification into the claims (for claim construction) and referencing the specification for definitions of claim terms (for indefiniteness analysis), this type of analysis will likely continue to be hotly litigated. Patent prosecutors may also want to consider providing such objective boundaries in the specification when using similar language to the terms at issue here.
  • As part of its analysis, the court considered whether the claim terms at issue add anything to the claims. Patent prosecutors and litigators may benefit from analyzing claims from this perspective.

For Further Information

If you have any questions about this Alert, please contact Christopher J. Tyson, Arvind Jairam, Mark Comtois, Patrick D. McPherson, any member of the Intellectual Property Practice Group or any attorney in the firm with whom you are in regular contact.


  1. Nautilus v. Biosig Instruments, Inc., 134 S. Ct. 2120 (2014) (slip opinion available at
  2. See Order Granting Motions for Summary Judgment in Abdou v. Alphatec Spine, No. 12-CV-1804, at 17 (S.D. Cal. Nov. 19, 2014) (hereinafter "Abdou Order").
  3. See id. at ("These claims all have some meaning and are not insolubly ambiguous, but they do fall short of the new, more rigorous reasonable certainty standard for indefiniteness.").
  4. The '153 Patent contains apparatus claims, and '855 Patent contains method claims. These patents are available at and
  5. The '153 Patent and '855 Patent were respectively filed on October 5, 2005, and November 23, 2005, and both claimed priority to a provisional application filed on November 24, 2004. For applications filed on or after September 16, 2012, the relevant statute is 35 U.S.C. § 112(b).
  6. See Abdou Order at 12-14, 16 [citing Nautilus, 134 S. Ct. at 2128-29; Interval Licensing LLC v. AOL, 766 F.3d 1364, 1370 (Fed. Cir. 2014)].
  7. See id. at 14-16.
  8. Claim 6 of the '153 Patent recites in relevant part: "[a]n instrument for implanting an orthopedic implant into a target space between skeletal segments, comprising … amount that is positionable at a defined anatomical relationship relative to the target space between the skeletal segments, wherein the mount attaches to the straight member of the insertion device at a proximal end of the insertion device and, when attached to the insertion device, the mount limits movement of the insertion device relative to the skeletal segments" (emphasis added).
  9. See Abdou Order at 15-16.
  10. See id. at 14-17.
  11. See id. at 12, 14-16 (citing Interval, 766 F.3d at 1371, for the requirement of "objective boundaries for those of skill in the art").
  12. See id.
  13. Claim 6 of the '855 Patent recites in relevant part: "[a] method for the delivery of an orthopedic implant onto a target location within a spinal column of a subject, comprising … a fixation member, having a first segment that attaches onto a proximal segment of the implant insertion member and a second segment that attaches onto a first surface, wherein, after attachment, the fixation member limits movement of the implant insertion member relative to the target location in at least one plane" (emphasis added).
  14. See Abdou Order at 14-15, 17 (S.D. Cal. Nov. 19, 2014).
  15. See id. at 17.
  16. See id. at 13.
  17. See id. at 15.
  18. See id.

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