Board affirms obviousness even when Applicant explains why primary reference does not benefit by substitution

Takeaway: The Examiner relied on a substitution rationale in rejecting claims to a vertebral disc prosthesis. The rejection replaced circumferentially oriented radiopaque markers in the primary reference with radially oriented marker from the secondary reference. The Applicant explained that the primary reference was radially symmetric, and thus has no use for radial markers. However, the Board affirmed, noting that the secondary reference used radial markers to position as well as orientation. (Ex parte De Villiers, PTAB 2013.)

Details:
Ex parte De Villiers
Appeal 2011008377; Appl. No. 11/982,431; Tech. Center 3700
Decided:  May 9, 2013

The application on appeal was directed to a prosthesis used in vertebral disc replacement. A representative claim on appeal read:

     18. An intervertebral prosthesis for insertion between adjacent vertebrae, the prosthesis comprising:
     upper and lower prosthesis plates locatable against respective vertebrae and having bearing surfaces thereon;
     a rigid preformed core located between the plates,
     the core having opposed bearing surfaces configured to cooperate with the bearing surfaces of the plates to allow the plates to slide in articulated manner over the core; and
     wherein the core is preformed with angularly spaced, radial passages and radially oriented pins located in the radial passages serving as radiographic markers.

In a Final Office Action, the Examiner rejected all the independent claims, and several dependents, as being obvious over Keller in view of Ray. According to the Examiner, Keller taught a prosthesis having the claimed plates and a core as claimed, with one difference: the radiographic marker in Keller was located in a passage extending around the circumference of the core. The Examiner then relied on Ray's teaching of a vertebral disc core for placement between adjacent vertebrae, where the core included radially oriented radiopaque markers.

Keller	Ray

In the body of the rejection, the Examiner explained the rationale for the combination as follows:

[It would have been obvious to] change the orientation of the circumferential marker/passage of Keller to a radially orientation as taught by Ray et forming preformed radial passages with radially oriented pins to allow radiographic viewing of said core to check location and orientation including radial orientation with predictable results.

On appeal, the Applicant did not dispute the Examiner's assertions about the disclosure of Keller or Ray, but instead attacked the Examiner's proffered reason to combine. First, Keller already included radiopaque markers. Second, the Office Action had provided no reason for modifying Keller to have markers that show rotational orientation of Keller's rotationally symmetric core:

   The rotational orientation of Keller's core 1 relative to it's retaining plates is irrelevant to the practitioner and patient, because the core 1 is a disc: any one angular orientation of the core is identical to any other angular orientation. [Thus,] the practitioner has absolutely no use for knowing the rotational orientation of the core. [In any event,] the exposed ends 10, 11 of the wire 9 would provide sufficient detail of the rotational orientation [under fluoroscopy].
   In stark contrast, the performance of Ray's disc nucleus prosthesis absolutely depends on its rotational orientation relative to the anatomical structures in which it is implanted. ... [T]he practitioner would have an intense need to know the rotational orientation of the prosthesis, so that it can perform its functions, e.g., "restore the natural pumping action of the disc space" [citing Ray].

In the Answer, the Examiner did not specifically address the Applicant's arguments, but instead noted similarities of the two prostheses:

Both Keller and Ray teach intervertebral prostheses for replacing an injured or malfunctioning nucleus. Both prostheses are mobile; note that the nucleus prosthesis of Ray is free to move within the disc space. Both prostheses use radiographic markers. Keller teaches, "A metal wire 9 is fitted in the groove 3, 4 is visible on X-rays and makes it possible to check the position of the sliding core 1 and to assess the articulation with the opposite bearing." Ray teaches "the spinal disc nucleus includes a radiopaque marker for indicating a location and orientation. Both Keller and Ray teach the marker is for the exact same purpose: to check position/location of the nucleus prosthesis.

The Examiner then defended his use of the substitution rationale:

 According to the MPEP [2141], this provides examplary rationale for substitution motivation, "simple substitution of one konwn element for another to obtain predictable results.". Note that the rejection is substituting the orientation and not adding additional markers as argued by  Appellant.

The Board affirmed the rejection and suggested that the Applicant had focused too much on Ray's use of markers to show rotational orientation:

While the placement of markers according to Ray may be used to define the orientation of an implant, the markers may also be used to simply define the location of the implant (FF4), which is how the markers are used in Keller (FF2). Claim 18 does not limit the use of markers to defining implant orientation. We agree with the Examiner’s rationale and adopt is as our own. KSR Int’l Co. v. Teleflex Inc ., 550 U.S. 398, 416 (2007) (“The combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results.”)

My two cents: In this and many other cases, the Board seems to think that substitution is a reason in and of itself.  But did the Board get this one wrong? Here, the Examiner relied on a specific advantage and the Applicant explained why this was not an advantage.

More specifically, the Examiner used the benefit "check location and orientation including radial orientation" as a reason to combine. But the Applicant rebutted by asserting that POSITA had no need to check orientation, and explained why this was the case.

The Board then seemed to fall back on the reasoning that a POISTA could have substituted Ray's markers as just a different way of marking location, not orientation, relying on this statement in Ray: "the radiopaque wires 38 further provide an indication of a location of the prosthesis spinal nucleus 20 upon implant."

This statement about location seems like a red herring to me, as that wasn't really in dispute. Certainly Ray's wires show where the implant is. But many wire arrangements could perform this function. Ray's wires were radial precisely because orientation as well as location was important. Why would a POSITA modify Keller's circumferentially arranged wires – which work just fine in Keller's implant  – to use Ray's radially arranged wires – which have no use in Keller's implant.

Sometimes a nail and a screw are equivalent substitutes, as both work as a fastener. But usually there's a reason why you use a nail rather than a screw, or vice versa. Isn't that the case here? Didn't the Applicant successfully rebut the Examiner's substitution rationale?