Back to Basics: In re Chudik offers a refresher on the law of anticipation for functional limitations

Cindy Chen | April 17, 2017

In re Chudik

March 27, 2017

Before Dyk, Reyna, and Stoll. Opinion by Reyna.


This decision is a refresher on the basic law of anticipation for functional claim elements. A prior art does not anticipate a functional claim element merely because it is “capable of” performing the recited function, but rather, such capability must be achieved without “distortion” or “modification” to the prior art.


Steven C. Chudik is a prominent orthopedic surgeon specializing in shoulder and knee surgery, and considering that he serves as a team physician for USA Swimming, it is little wonder that among his claims to fame are his inventions relating to minimally invasive shoulder replacement surgery.

U.S. Patent Application No. 11/525,631 (the “631 application”) at issue in this decision relates to a shoulder replacement surgery that bypasses and spares the rotator cuff. A passage is drilled into the bones surrounding the rotator cuff, in order to expose the shoulder joint. A reaming tool is then guided through the passage until it reaches the exposed joint. The shoulder joint is a “ball and socket” joint, with the glenoid being the “socket” and the head of the upper arm bone being the “ball”. The reaming tool removes a minimal amount of bone from the surface of the glenoid to prepare its surface for an implant. The implant is then fixed to the prepared surface.

The current claims of the 631 application are directed to the implant. Independent claims 1 and 40 were at issue on appeal, and recited the following:

  1.  A glenoid implant, comprising:

a shell having a protruding surface on a first side arranged to engage the surface of a cavity formed in a glenoid extending between peripheral glenoid surface, and

a flat surface on the first side adjacent the protruding surface arranged to engage the peripheral glenoid surfaces adjacent the cavity, and

a wear-resistant articulating surface on a second side opposite the flat surface and the protruding surface.

40.  A glenoid implant comprising:

a protruding surface on a first side arranged to engage the surface of a cavity formed in a glenoid extending between peripheral glenoid surfaces, and

a substantially planar wear-resistant articulating surface on a second side opposite the protruding surface.

The 631 application illustrates the main structures of the claimed implant as follows:

During prosecution, the Examiner rejected claims 1 and 40 as being anticipated by Rambert (FR2579454) and Bouttens (WO 01/47442A1), respectively. The annotated figures below illustrate the Examiner’s interpretation of Rambert (left figure) and Bouttens (right figure):


When Chudik appealed the rejections to the Patent Trial and Appeal Board, the Board affirmed the Examiner’s anticipation rejections. As to Rambert, the Board reasoned that:

[I]ndependent claim 1 is an apparatus claim and does not require the recited surfaces to “engage” the specified glenoid regions; rather, independent claim 1 requires only that the recited surfaces be ‘arranged’ for such engagement…the fact that Rambert’s protruding and flat surfaces are not described or depicted as actually engaging the specified glenoid regions is not dispositive, as they can still be arranged to do so.

As to Bouttens, the Board faulted Chudik for failing to show that “Bouttens’s surface 11 is structurally incapable of engaging a glenoid cavity that matches its protruding profile”, since “the claim language does not specify shape characteristics of the cavity, and the Specification conveys that the cavity can have ‘any’ shape that matches that of the protruding surface”.

The Federal Circuit disagreed with the Examiner and the Board.

First, noting that there had been no interpretation of “arranged to”, the Federal Circuit “assumed” that the term “is analogous to ‘adapted to,’ which means ‘made to,’ ‘designed to,’ or ‘configured to’” and which “occasionally has a broader meaning of ‘capable of’ or ‘suitable for’.” According to the Federal Circuit:

Claim 1 is indeed an apparatus claim, and the “arranged to engage” language could imply that the protruding surface on the flat side need not always actually engage the glenoid cavity surface. However, it must be at least capable of doing so.

Next, the Federal Circuit found that in fact, in Rambert, the protruding surface on element 27b could not be “arranged to engage” the glenoid cavity without removing element 27a situated between element 27b and the glenoid surface. Here, the Federal Circuit reiterated the basic standard for anticipation:

Prior art that ‘must be distorted from its obvious design’ does not anticipate a new invention. [In re Wells, 53 F.3d 537, 539 (CCPA 1931)]; see also [Topliff v. Topliff, 145 U.S. 156, 161 (1982)] (prior art that must be modified “to accomplish the function performed by the patent in question” does not anticipate). Neither the Examiner nor the Board described how the protruding surface of Rambert’s element 27b is capable of engaging the surface of the glenoid cavity without removing element 27a, i.e., tearing the invention apart.

The Federal Circuit found similar flaws in the USPTO’s interpretation of Bouttens. In Bouttens, the protruding surface clearly faces the upper arm bone, not the glenoid cavity, so that the protruding surface could not have been “arranged to engage the surface of a cavity formed in a glenoid”, as required in Chudik’s claims:

The Board’s reasoning only makes sense if the user rotates Bouttens 180 degrees, thereby rendering the protruding surface 11 capable of engaging the glenoid cavity instead of the humerus…. [R]otating Bouttens so that the protruding surface faces the glenoid cavity would require relocating the screws for Bouttens to remain operable. This endeavor would constitute a significant and impermissible modification…. [T]he Board failed to describe how a user could rotate Bouttens without modification while continuing ‘to accomplish the function performed by’ the ‘631 application.

The Federal Circuit thus reversed the anticipation rejections. The application is expected to return to the Examiner for further examination.

Interestingly, this decision (“Chudik II”) was actually Chudik’s second victory at the Federal Circuit this year.

In a non-precedential decision from January of this year, In re Chudik I, the Federal Circuit reversed the USPTO’s anticipation rejection of Chudik’s claims in U.S. Patent Application No. 11/701,902 (the “902 application”).

There, the claims were directed to a tool for repairing damaged anterior cruciate ligaments (ACL). The only claim on appeal recited a scalpel comprising, among other things, “a blade having a blade end configured for creating a passageway through skin and soft-tissue to a target site on a bone”.

On appeal to the Federal Circuit, Chudik did not challenge the USPTO’s determination that the allegedly anticipatory reference disclosed all the structural limitations in the claim. Chudik disputed only the USPTO’s findings regarding the functional “configured for” limitation. The USPTO argued that the prior art scalpel was “inherently capable” of “creating a passageway to through skin and soft-tissue to a target site on a bone”. The Federal Circuit disagreed, finding that the USPTO’s argument contradicted explicit teachings in the cited reference. Namely, the cited reference explicitly disclosed that the prior art scalpel was designed to prevent deep cuts in the skin, because such cuts could sever structures near the skin and result in “disastrous consequences”. The 902 application has since been remanded to the Examiner for further examination.

A side-by-side comparison of the Federal Circuit’s two Chudik decisions is particularly interesting for their discussions on one of Examiners’ favorite cases: In re Schreiber, 128 F.3d 1473 (Fed. Cir. 1997). Examiners like to bandy the Schreiber case about whenever a claim describes an apparatus invention functionally. They would cite the case to make the argument that a prior art apparatus is “inherently capable” of performing a recited function.

However, in Chudik I, the Federal Circuit faulted the USPTO for relying on Schreiber to improperly shift the burden of proof to the applicant:

Under Schreiber, if it is established that an examiner has reason to believe that a functional limitation is taught in the single prior art reference, the burden shifts to the applicant to disprove the examiner’s belief. An examiner’s belief, however, must be tethered to or grounded in some rationale so as to establish a prima facie case of anticipation…. Here, the examiner believed—and the Board affirmed this belief—that the blade of the [prior art] scalpel was inherently capable of reaching a shallow bone. The examiner, however, gave no justification for this belief…. If anything, [the prior art] explains that its design specifically prevents incisions that could damage structures near the skin.

In Chudik II, the Federal Circuit faulted the USPTO’s reliance on Schreiber as being inapposite:

The government relies heavily on In re Schreiber, 128 F.3d 1473 (Fed. Cir. 1997), which involved an old structure from the prior art being put to a new use. But that is not the situation here, because Rambert teaches a different structure than the ‘631 application with an identical use.


 Don’t be too quick to give up on functional limitations in an apparatus claim, especially not in the context of an anticipation rejection. An argument against the rejection may be formulated based on the modifications that must be made to the prior art before it can perform the recited functions.

In re Chudik I_nonprec (Fed Cir Jan. 9 2017)

In re Chudik II (Fed Cir Mar. 27 2017)

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