Ex Parte Link

Board of Patent Appeals and Interferences

May 23, 2012

11171305 (B.P.A.I. May. 23, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte HELMUT D. LINK
__________

Appeal 2011-001218
Application 11/171,305
Technology Center 3700
__________

Before JEFFREY N. FREDMAN, ERICA A. FRANKLIN, and
JACQUELINE WRIGHT BONILLA, Administrative Patent Judges.

BONILLA, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims directed to a
hip joint prosthesis comprising a stem and a trochanteric surface part. The
Examiner has rejected the claims as obvious. We have jurisdiction under 35
U.S.C. § 6(b). We affirm.

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STATEMENT OF THE CASE
The instant Specification discloses a hip joint prosthesis with a stem
to be inserted into a femur. (Spec. 1, ll. 6-7.) The prosthesis also includes a
trochanteric surface that lies within the trochanteric region of the femur. (Id.
at 4, ll. 14-17.) The trochanteric surface area contains an osteoinductive
substance and comprises pores or undercuts that allow osteoinduction, i.e.,
the formation of bone substance that adheres to the trochanteric surface and
anchors it with a formed fit. (Id. at ll. 7-12.) Figure 1 in the Specification
(shown ahead) depicts an embodiment of the prosthesis, where hatched
region (4) corresponds to the trochanteric region, and projection (13) of the
prosthesis comprises bores (14). In Figure 1, (2) corresponds to the
diaphysis of the femur bone, and (12) corresponds to the stem of the
prosthesis. (Id. at 7, ll. 1-5.)
Claims 1-11 are on appeal. Claim 1 is the only independent claim,
and is representative:
1. A hip joint prosthesis configured for uncemented use
comprising a stem configured for being anchored in a diaphysis of a
femur, a trochanteric surface part configured to lie in a trochanteric
region of the femur, and an osteoinductive substance applied to the
trochanteric surface of the prosthesis, wherein a surface of the stem is
configured for direct contact with bone material of the femur and
wherein the surface of the stem is free from an osteoinductive
substance.
Dependent claim 3 recites that the osteoinductive substance comprises a
bisphosphonate or a bone morphologic protein (BMP). Appellant does not
argue claims separately and therefore the pending claims stand or fall
together. 37 C.F.R. § 41.37(c)(1)(vii).
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The claims stand rejected as follows:
• Claims 1-6 and 10 under 35 U.S.C. § 103(a) as obvious over
Kampner (U.S. Pat. No. 4,840,632, issued Jun. 20, 1989) in view of Agrawal
et al. (U.S. Pat. No. 5,947,893, issued Sep. 7, 1999).
• Claims 7-9 and 11 under 35 U.S.C. § 103(a) as obvious over
Kampner in view of Agrawal and Elloy (WO 93/08771, published May 13,
1993).
I.
Issues
As pertaining to the obviousness rejection of claims 1-6 and 10, the
first issue is whether Kampner discloses or suggests a stem “configured for
being anchored in a diaphysis of a femur” and “configured for direct contact
with bone material of the femur” as recited in claim 1. The second issue is
whether Kampner teaches away from applying an osteoinductive substance
to the trochanteric surface part of the prosthesis disclosed in Kampner.
Principles of Law
The Examiner bears the initial burden, on review of the prior art or on
any other ground, of presenting a prima facie case of unpatentability. In re
Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992). If the Examiner meets that
initial burden, the burden of coming forward with evidence or argument
shifts to the applicant. In re Rijckaert, 9 F.3d 1531, 1532 (Fed. Cir. 1993).
After the applicant submits such evidence or argument, the PTO then
determines patentability “on the totality of the record, by a preponderance of
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evidence with due consideration to persuasiveness of argument.” Oetiker,
977 F.2d at 1445.
Analysis
As discussed by the Examiner, Kampner teaches a relevant hip joint
prosthesis comprising a stem and an intertrochanteric body that includes
“interior and exterior load transferring surfaces” that “are porous to promote
bone ingrowth and assure a firm, permanent fixation of the implant,” thereby
eliminating the need for cement. (Kampner, col. 4, ll. 26-38; Ans. 4.) In
light of such teachings in Kampner, we agree with the Examiner that it
would have been prima facie obvious to apply an osteoinductive substance,
such as BMP disclosed in Agrawal (col. 4, ll. 47-48; col. 7, ll. 17-21), to a
trochanteric surface part in the prosthesis disclosed in Kampner to further
promote bone ingrowth and assure fixation, i.e., to help provide
advantageous features described in both Kampner and Agrawal. (Ans. 4-5;
Agrawal, Abstract.)
As correctly noted by Appellants (App. Br. 4-5), Kampner describes
two different embodiments of a hip prosthesis, where “[l]oad transfer from
the elongated stem to the bone is eliminated in two ways.” (Kampner, col.
4, ll. 40-42.) One embodiment comprises a stem having “a smooth surface
on a non-absorbable material, such as metal, polymer, ceramic, etc., to
prevent bony ingrowth.” (Id. at 42-47.) Another embodiment uses “a
resorbable biodegradable material, e.g., ceramic, polylactic acid, etc., for the
stem,” which “can be fabricated to resorb over any desired time period,
allowing an adequate period of time to elapse for bony ingrowth about the
intertrochanteric body portion.” (Id. at 47-54.) In the reabsorbable
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embodiment, “[t]he end result is a stemless femoral component filling only
the remaining neck and intertrochanteric region of the femur.” (Id. at 54-
59.)
Appellant also asserts that both embodiments describe “the opposite
of the claimed invention, which requires that the stem be configured for
being anchored in a diaphysis of a femur (see, e.g., specification, page 7,
lines 1 to 3), and that a surface of the stem be configured for direct contact
with bone material of the femur.” (App. Br. 4; see also Reply Br. 2.)
According to Appellant, the stem in Kampner “resorbs or has a smaller
diameter than the cavity of the femur, so the stem is not configured for direct
contact with bone material of the femur as claimed.” (App. Br. 5.) In this
regard, Appellant notes that Kampner teaches that the “function [of the
stem] is only to accurately guide and orient the femoral component during
implantation” (citing Kampner, col. 4, ll. 39-42, col. 9, ll. 39-43), and “it is
preferred that no firm contact exists between the femoral cortical bone and
the stem” (citing Kampner, col. 11, ll. 32-35). (Reply Br. 3.)
We agree with the Examiner, however, that Appellant‟s arguments
fail “to account for the entire duration of time that the stem is still intact
before biodegrading.” (Ans. 6.) In other words, Kampner teaches or
suggests a relevant prosthesis having a reabsorbable stem that is “configured
for being anchored in a diaphysis of a femur” and “for direct contact with
bone material of the femur” as claimed, even though the reabsorbable stem
eventually, after insertion, reabsorbs over time (where the prosthesis
eventually become stemless) after bony ingrowth occurs at the trochanteric
surface part of the prosthesis.
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Here, the reabsorbable stem in Kampner differs from the smooth non-
absorbable stem embodiment in relevant part. Specifically, in the non-
absorbable embodiment, the “stem has a smooth surface to prevent bony
ingrowth and ideally is of a smaller diameter than the medullary cavity of
the femur in which it is inserted, so that there will be no abnormal
transference of stresses to this area of femur.” (Kampner, col. 9, ll. 42-47.)
Likewise, Kampner teaches “it is preferred that no firm contact exists
between the femoral cortical bone and the stem (non-resorbable).” (Id. at
col. 11, ll. 32-36 (emphasis added).) Kampner does not suggest, however,
that the reabsorbable stem must have a smaller diameter or have no contact
with bone when it is first inserted into the femur. Even the Applicant
acknowledges the difference between the two embodiments when stating
that stem in Kampner “resorbs or has a smaller diameter than the cavity of
the femur.” (App. Br. 5 (emphasis added).)
This distinction between a reabsorbable stem and a smooth non-
absorbable stem explains why Figure 1 in Kampner depicts a stem
embedded in, i.e., in direct contact with, the diaphysis of the femur, just as
seen in Figure 1 of the instant Specification.
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Figure 1 of Specification Figure 1 of Kampner
Both Figures 1 depict a sectional view of a hip joint prosthesis in an upper
portion of a femur, where Figure 1 of Kampner also depicts a pelvis.
Regarding the phrase “configured for being anchored in a diaphysis”
recited in claim 1, we note that the Specification states with regard to Figure
1 that “stem 12 is designed and implanted in such a way that it is firmly
anchored in the diaphysis 2 of the bone” and that “[t]his type of anchoring
leads to great relief of the pressure on the trochanteric bone region.” (Spec.
7.) Nothing in the instant Specification, including Figure 1, indicates that
the stem itself is “anchored” by any means other than by placing the stem
inside the diaphysis of a femur. For example, the Specification does not
mention, and Figure 1 of the Specification does not show, the use of any
additional anchor piece in a diaphysis of a femur. Instead, in relevant part,
Figure 1 of the Specification looks exactly the same as Figure 1 in Kampner,
i.e., that the stem is anchored in, and in direct contact with, the diaphysis of
the femur.
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Thus, we agree with the Examiner that in Kampner “the stem is
located in the diaphysis of a femur when implanted; therefore, the stem is
necessarily anchored in the diaphysis of a femur.” (Ans. 6.) We also agree
that “even if Kampner is „ideally of a smaller diameter than the medullary
cavity of the femur‟ (see, e.g., Kampner, col. 9, lines 44-47)” as pertaining
to one disclosed embodiment, “it need not necessarily be so, even by the
teaching of Kampner” (Ans. 6), especially as it relates to the biodegradable
stem embodiment.
Additionally, we point out that although the stated function of the
stem in Kampner “is only to accurately guide and orient the femoral
component during implantation” (Kampner, col. 4, ll. 39-40), the guidance
and orientation function of the stem would be better served if the stem is
unable to move within the femur after insertion while osteoinduction occurs
at the trochanteric surface part of the prosthesis. After osteoinduction
occurs, however, a stem with a smaller diameter (such as would necessarily
be the case after the stem reabsorbs) is advantageous for the reasons taught
in Kampner, i.e., so that “undesirable shear stresses, and an unnatural
loading of the femur (over the length of the stem) are prevented,” especially
during long term use. (Id. at ll. 56-59.)
Lastly, we are not persuaded by Appellant‟s arguments that Kampner
teaches away from the claimed invention. Appellant argues that Kampner
emphasizes that force transmission “concentrates on compression forces,”
and “there is no reason why one of ordinary skill in the art would apply an
osteoinductive substance which is used to improve the transmission of
tensile, not compressive, forces.” (App. Br. 5 (emphasis in original); see
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also Reply Br. 4-5.) Regardless of transmission of tensile versus
compression forces, however, Kampner provides ample reason for one of
ordinary skill in the art to apply an osteoinductive substance to the part of
the prosthesis (i.e., a trochanteric surface part) that Kampner teaches is
“porous to promote bone ingrowth and assure a firm, permanent fixation of
the implant.” (Kampner, col. 4, ll. 27-33.) As discussed above, a skilled
artisan would have understood that the osteoinductive substances described
in Agrawal would be advantageous to help facilitate such features.
Conclusion of Law
We conclude that Kampner discloses, or at least suggests, a stem
“configured for being anchored in a diaphysis of a femur” and “configured
for direct contact with bone material of the femur” as recited in claim 1. We
also conclude that Kampner does not teach away from applying an
osteoinductive substance to the trochanteric surface part of the prosthesis
disclosed in Kampner. Thus, we conclude that the preponderance of
evidence, based on the record before us, establishes that claim 1, as well as
claims 2-6 and 10 (not argued separately by Appellant), are obvious over
Kampner in view of Agrawal.
II.
Issue
Appellant argues that the obviousness rejection of claims 7-9 and 11
over Kampner in view of Agrawal and Elloy should reversed because Elloy
“fails to compensate for the deficiencies of Kampner and Agrawal.” (App.
Br. 6.) According to Appellant, “Elloy, similarly to Kampner and Agrawal,
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fails to disclosure or suggest a hip prosthesis for uncemented use in which an
osteoinductive substance is applied to a trochanteric surface of a prosthesis
and a stem surface of the prosthesis is configured for direct contact with
bone material free from an osteoinductive substance as required by claim 1.”
(Id.)
Thus, the issue here is whether the preponderance of evidence, based
on the record before us, establishes that claims 7-9 and 11 are obvious over
Kampner in view of Agrawal and Elloy, in light of our findings and
conclusion above with regard to independent claim 1.
Analysis
We agree with the Examiner that it would have been obvious to
provide the implant of Kampner in view of Agrawal with a detachable
wedge-shaped projection as disclosed in Elloy “in order to facilitate
attachment of the implant to trochanteric bone tissue.” (Ans. 5.) Appellant
does not dispute this finding.
Instead, as noted by the Examiner, “Appellant‟s arguments do not
even address the teaching that Elloy provides or the motivation for which it
was combined with the other references.” (Ans. 7.) Rather, Appellant relies
on previous arguments, discussed in the section above, that Kampner does
not disclose or suggest a stem “configured for being anchored in a diaphysis
of a femur” and “configured for direct contact with bone material of the
femur” as recited in claim 1.
For the reasons discussed above, we agree with the Examiner that
Kampner discloses, or at least suggests, such a stem in the form of a
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reabsorbable stem embodiment. Appellant has not supplied argument or
evidence that persuades us otherwise.
Conclusion of Law
We conclude that the preponderance of evidence, based on the record
before us, establishes that claims 7-9 and 11 are obvious over Kampner in
view of Agrawal and Elloy, in light of our findings and conclusion above
with regard to claim 1.
SUMMARY
We affirm the rejection of claims 1-6 and 10 under 35 U.S.C. § 103(a)
as obvious over Kampner in view of Agrawal. We also affirm the rejection
of claims 7-9 and 11 as obvious over Kampner in view of Agrawal and
Elloy.

TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

AFFIRMED

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