Ex Parte May et al

Patent Trial and Appeal Board

Dec 9, 2013

12253259 (P.T.A.B. Dec. 9, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
12/253,259 10/17/2008 Brian M. May 5490-000744/US 8941
94507 7590 12/09/2013
Harness Dickey & Pierce (Biomet)
5445 Corporate Drive
Suite 200
Troy, MI 48098
EXAMINER
STEWART, JASON-DENNIS NEILKEN
ART UNIT PAPER NUMBER
3738
MAIL DATE DELIVERY MODE
12/09/2013 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte BRIAN M. MAY and MUKESH KUMAR1
__________

Appeal 2012-003054
Application 12/253,259
Technology Center 3700
__________

Before TONI R. SCHEINER, JEFFREY N. FREDMAN, and
ULRIKE W. JENKS, Administrative Patent Judges.

SCHEINER, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 from the final rejection of
claims 1-6 and 8-20, directed to a knee joint prosthesis and a method of
implanting it in a tibia. The Examiner has rejected the claims as obvious.
We have jurisdiction under 35 U.S.C. § 6(b).
We affirm-in-part.

1 Appellants identify the Real Party-In-Interest as Biomet Manufacturing
Corp. (App. Br. 2.)

Appeal 2012-003054
Application 12/253,259
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STATEMENT OF THE CASE
Claims 1-6, 8-15, and 17-20 are pending and on appeal. Claims 7 and
16 have been canceled (see App. Br. 2; Ans. 4). Representative claims 1 and
8 are reproduced below:
1. A knee joint prosthesis comprising:
a tibial component including a tibial tray, said tibial tray comprising:
a platform-like tray having a superior bearing engaging surface
and an inferior surface, said platform-like tray defining a tray
perimeter and a first height measured between said superior bearing
engaging surface and said inferior surface;
a raised wall formed on and extending from said inferior
surface of said platform-like tray, said raised wall offset inboard
relative to said tray perimeter and configured to provide increased
rigidity of said platform-like tray; and
porous material disposed on said inferior surface of said
platform-like tray at a location generally between said raised wall and
said tray perimeter, said porous material having a second height
measured between said inferior surface of said platform-like tray and
a bone engaging surface of said porous material, said second height
being greater than said first height.
8. The knee joint prosthesis of claim 1 wherein said platform-like tray
further comprises, a first support wall formed on said inferior surface
and extending between a generally anterior/lateral position to a
posterior/medial position.
The claims stand rejected under 35 U.S.C. § 103(a) as follows:
Claims 1-6, 11-15, 19, and 20 as unpatentable over Incavo et al. (US
5,480,444, issued January 2, 1996) and Bernero et al. (US 2006/0052875
A1, published March 9, 2006).
Claims 8-10, 17, and 18 as unpatentable over Incavo et al., Bernero et
al., and Barnett et al. (US 7,740,662 B2, issued June 22, 2010).
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FINDINGS OF FACT
1. Incavo teaches that:
Fixation of the tibia, femur and patella components of [a]
pro[s]thesis during implantation has customarily involved either
bone cement or natural bone ingrowth. Orthopedic surgeons
typically prefer cementless fixation for what is considered to be
its potential to provide long term implant stability. Knee
replacement pro[s]thes[e]s wherein fixation is accomplished
through bone ingrowth may have a porous layer to facilitate
bone ingrowth. For instance . . . a fibrous metal mesh layer to
facilitate bone ingrowth.
(Incavo, col. 1, ll. 39-48.)
2. Incavo teaches that “peripherally placed cancellous screws,
sleeves, central stems and pegs” have been used in an effort to avoid
“inconsistent results with ingrowth [stemming] from the inability for implant
designs to provide adequate initial fixation in order for bone growth to
occur” (Incavo, col. 2, ll. 11-14, 33-35).
3. Incavo teaches that cemented prosthesis designs “have met with
more clinical success and a lower incidence of loosening due to
micromotion” (Incavo, col. 2, ll. 42-44), but “even bone cement fixated
prosthetic components are susceptible to loosening” (id. at col. 2, ll. 54-55).
4. Incavo discusses prior art “[h]ybrid components [which] utilize
both cement and bone ingrowth for fixation” (Incavo, col. 2, ll. 59-60), e.g.,
a tibial tray comprising a “central stem and pegs . . . coated with a porous
metal to promote bone ingrowth” (Incavo, col. 3, ll. 1-2). Incavo notes that
this particular hybrid tibial tray has “disadvantages primarily resulting from
the placement of the porous bone ingrowth material on the central stem and
pegs” (id. at col. 3, ll. 15-17). For example, “the bone ingrowth area is of
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Application 12/253,259

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limited surface area and does not effectively utilize the larger surface area of
the upper end of the tibia for bone ingrowth” (id. at col. 3, ll. 25-27).
5. Incavo discloses another hybrid tibial tray with “a distal surface
(undersurface) comprising a peripheral surface for receiving bone cement
and a central surface which promotes bone ingrowth. A central stem extends
from the distal surface of the plate” (Incavo, col. 4, ll. 18-21).
6. Figure 6 of Incavo is reproduced below:

Figure 6 is a bottom view of an embodiment of Incavo’s tibial tray,
showing “a peripheral surface 15 for receiving bone cement and a [porous]
central surface 16 which promotes bone ingrowth” (Incavo, col. 5, ll. 28-30).
In addition, “a raised shoulder 22 . . . completely surround[s] central surface
16” (id. at col. 6, ll. 9-10). During implantation, the raised shoulder “is
implanted within the tibia bone tissue for fixation to the tibia” (id. at col. 6,
ll. 40-42).
7. Bernero discloses a ceramic monoblock “tibial component
adapted for fixation to an appropriately resected upper end of the patient’s
tibia” (Bernero ¶¶ 5, 12).
The tibial ceramic monoblock structure . . . includes an
underside region defined by a ceramic porous bone ingrowth
surface for secure ingrowth affixation to natural tibial bone . . . .
An alternate form would be the attachment of the component to
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the natural tibial bone through cementation. The porous
structure may allow for bone interdigitation. A further alternate
method for cementation would not include a porous section and
be replaced with a slot or pocket that will receive the cement
and may or may not include undercut features for tensile
strength.
(Id. at ¶ 12.)
8. Figure 3 of Bernero is reproduced below:

Figure 3 is a bottom plan view of the ceramic monoblock tibial
component of Bernero’s prosthesis, showing the “downwardly protruding
fixation post 32 . . . for seated reception into a resected upper end of the
patient’s tibia” (Bernero ¶ 38), and the “ceramic porous bone ingrowth
surface coating or lining 14 formed on the underside of the tibial platform
22, wherein this coating or lining . . . provides an effective bone ingrowth
surface for achieving secure and stable bone ingrowth affixation of the
ceramic tibial component 12 with patient’s tibia” (Bernero ¶ 40).
9. The present Specification teaches that the tibial tray of the
claimed tibial prosthesis “can be connected to a tibia . . . by any suitable
method” (Spec. ¶ 34).
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DISCUSSION
Claims 1-6, 11-15, 19, and 20
The Examiner finds, in relevant part, that Incavo discloses a “tibial
prosthesis having a tray component 11 having a raised wall 22 extending
from the inferior surface of the wall and offset inboard relative to the tray
perimeter” (Ans. 5), and “a stem 19 that extends inferiorly from the tray”
(id.). The Examiner finds that Incavo “also teaches a porous surface 17 that
extends from the raised wall 22 to the stem 19 on the inferior surface of the
tray . . . which is discontinuous at the wall 22” (id.), but acknowledges that
the porous surface is not present “between the raised wall and the perimeter
of the tray on the inferior side” (id. at 6), as required by these claims.
However, the Examiner finds that Bernero discloses “a tibial tray with
a stem 32 wherein the entire inferior surface is coated with porous material
14” (id.).
The Examiner concludes that it would have been obvious for one of
ordinary skill in the art to modify Incavo’s tibial prosthesis “by making the
entire inferior surface of the tray porous as taught by Bernero in order to
facilitate secure ingrowth affixation to a natural tibia bone as taught by
Bernero” (id.).
Appellants acknowledge that Bernero “disclose[s] porous material on
an inferior surface of [the] tibial tray,” but contend that Incavo “specifically
teaches away from incorporating such porous material between the raised
wall and the perimeter” (App. Br. 8), and “specifically requires the use of
both bone cement and porous material for overcoming prior art
disadvantages” (id. at 9).
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Appellants’ argument does not persuade us that the Examiner’s
conclusion is unfounded. A reference is said to “teach away” from a
claimed invention when it “suggests that the line of development flowing
from the reference's disclosure is unlikely to be productive of the result
sought by the applicant.” In re Gurley, 27 F.3d 551, 553 (Fed. Cir. 1994).
That is not the case here. If anything, these references merely illustrate the
trade-offs that those of ordinary skill in this art recognize and routinely
consider in designing prostheses.
For example, Incavo favors hybrid fixation, but nevertheless provides
evidence that “[f]ixation of the tibia . . . components of the pro[s]thesis
during implantation . . . customarily involved either bone cement or natural
bone ingrowth” at the time of the invention (Incavo, col. 1, ll. 39-41; FF1),
and that both techniques were understood to have various advantages and
disadvantages. Similarly, Bernero teaches that its ceramic monoblock tibial
component can be fixed to the tibia by bone cement or bone ingrowth into a
porous surface, and explicitly discloses a tibial tray in which the entire
inferior surface of the tray is porous (FFs 7, 8).2
Claim 4
Appellants contend that “Claim 4 further provides that ‘said porous
material is disposed in a location generally between said raised wall and said
stem’” as well as between the raised wall and the perimeter (App. Br. 9).

2 Notably, Incavo teaches that one disadvantage of a particular prior art
prosthesis stems from its failure to “effectively utilize the larger surface area
of the upper end of the tibia for bone ingrowth” (Incavo, col. 3, ll. 25-26;
FF4). Clearly, this would not be an issue with Bernero’s prosthesis.
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This argument is not persuasive as both Incavo and Bernero disclose
tibial trays with porous material surrounding the stem.
Claim 12
Finally, Appellants contend that claim 12 requires, among other
things, “first and second porous metal portions [which] are discontinuous at
[the] bone engaging end face” of a raised wall formed on the inferior surface
of the tibial tray, such that the end face is free of porous metal and
configured to directly engage bone (App. Br. 9-10). Appellants contend that
“the collective art of record fails to teach or render obvious such a knee joint
prosthesis” (id. at 10).
This argument is not persuasive. As noted by the Examiner, Incavo’s
porous surface is discontinuous at the raised wall 22 (Ans. 5), while Incavo
teaches that raised shoulder 22 “is implanted within the tibia bone tissue for
fixation to the tibia” (Incavo, col. 6, ll. 40-42; FF6).
Accordingly, the rejection of claims 1, 4, and 12 as unpatentable over
Incavo and Bernero is affirmed. The rejection of claims 2, 3, 5, 6, 11, 13-15,
19, and 20 is affirmed as well, as they were not separately argued. See
37 C.F.R. § 41.37(c)(1)(vii).
Claims 8-10, 17, and 18
The Examiner rejected claims 8-10, 17, and 18 as unpatentable over
Incavo, Bernero, and Barnett. These claims require, in relevant part, a
support wall formed on the inferior surface of the tibial tray, and extending
between “a generally anterior/lateral position to a posterior/medial position”
(claim 8), “a generally anterior/medial position to a posterior/lateral
position” (claims 9, 10), or “radially” (claims 17, 18).
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The Examiner acknowledges that neither Incavo nor Bernero teaches
“first and second supports on the inferior surface of the tray that extend[]
between an anterior/lateral position to a posterior/medial position” (Ans. 6-
7). However, the Examiner finds that Barnett discloses “a tibial tray
embodiment having raised walls 150 that extend between a generally
anterior/lateral position to a posterior/medial position” (id. at 7).
The Examiner concludes that it would have been obvious for one of
ordinary skill in the art “to modify the . . . tibial tray with the porous coating
of Incavo in view of Bernero with the inferiorly extending walls of Barnett
in order to provide fixation without the use of a threaded screw as taught by
Barnett” (id.).
Nevertheless, as Appellants correctly point out, Barnett’s elements
150 are not on the tibial tray at all (see Figures 5 and 6). Rather, they “are
provided on a bearing component and are used to interlock with a tibial tray”
(App. Br. 10-11).
As the Examiner has not addressed this deficiency in the references,
we are constrained to reverse this rejection.
SUMMARY
The rejection of claims 1-6, 11-15, 19, and 20 as unpatentable over
Incavo and Bernero is affirmed.
The rejection of claims 8-10, 17, and 18 as unpatentable over Incavo,
Bernero, and Barnett is reversed.
Appeal 2012-003054
Application 12/253,259

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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-IN-PART

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