U.S. patent number RE48,163 [Application Number 15/972,333] was granted by the patent office on 2020-08-18 for surgical reaming instrument for shaping a bone cavity.
This patent grant is currently assigned to Howmedica Osteonics Corp.. The grantee listed for this patent is Howmedica Osteonics Corp.. Invention is credited to Jeffery Arnett, Mark Mooradian, Steven Primiano, Damon J. Servidio.
View All Diagrams
United States Patent |
RE48,163 |
Primiano , et al. |
August 18, 2020 |
Surgical reaming instrument for shaping a bone cavity
Abstract
Disclosed herein are systems and methods for shaping bone voids
during revision procedures of total knee replacements. The systems
disclosed herein generally include a cannulated reamer assembly, a
reaming guide assembly, a guide tube assembly, a trial stem
assembly, and an optional insertion/removal tool. Metaphyseal
reconstruction devices can be used to fill the bone voids in
conjunction with the systems and methods disclosed herein.
Inventors: |
Primiano; Steven (Holmdel,
NJ), Servidio; Damon J. (Towaco, NJ), Mooradian; Mark
(San Diego, CA), Arnett; Jeffery (Gilbert, AZ) |
Applicant: |
Name |
City |
State |
Country |
Type |
Howmedica Osteonics Corp. |
Mahwah |
NJ |
US |
|
|
Assignee: |
Howmedica Osteonics Corp.
(Mahwah, NJ)
|
Family
ID: |
47459150 |
Appl.
No.: |
15/972,333 |
Filed: |
May 7, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
15493542 |
Apr 21, 2017 |
RE47149 |
|
|
|
61568808 |
Dec 9, 2011 |
|
|
|
Reissue of: |
13708491 |
Dec 7, 2012 |
9011444 |
Apr 21, 2015 |
|
Reissue of: |
13708491 |
Dec 7, 2012 |
9011444 |
Apr 21, 2015 |
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B
17/17 (20130101); A61B 17/16 (20130101); A61F
2/4684 (20130101); A61B 17/1764 (20130101); A61B
17/1717 (20130101); A61B 17/1675 (20130101); A61B
17/16 (20130101); A61B 17/1637 (20130101); A61B
17/17 (20130101); A61F 2/389 (20130101); A61F
2/4684 (20130101); A61B 17/1764 (20130101); A61F
2/389 (20130101); A61B 17/162 (20130101); A61F
2/3859 (20130101); A61F 2/30734 (20130101); A61B
17/1675 (20130101) |
Current International
Class: |
A61B
17/16 (20060101); A61F 2/38 (20060101); A61B
17/17 (20060101); A61F 2/46 (20060101); A61F
2/30 (20060101) |
Field of
Search: |
;623/18.11,20.14,20.16,20.32,23.48 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2842847 |
|
Jan 1980 |
|
DE |
|
2842847 |
|
Apr 1980 |
|
DE |
|
0016480 |
|
Oct 1980 |
|
EP |
|
2168586 |
|
Mar 2010 |
|
EP |
|
2181071 |
|
May 2010 |
|
EP |
|
2181672 |
|
May 2010 |
|
EP |
|
2159416 |
|
Dec 1985 |
|
GB |
|
03094698 |
|
Nov 2003 |
|
WO |
|
2006127486 |
|
Nov 2006 |
|
WO |
|
2008069800 |
|
Jun 2008 |
|
WO |
|
Other References
Schreurs, et al., Femoral Component Revision with Use of Impaction
Bone-Grafting and a Cemented Polished Stem. Surgical Technique, The
Journal of Bone & Joint Surgery, Sep. 2006, pp. 259-274. cited
by applicant .
Lonner, et al., Impaction Grafting and Wire Mesh for Uncontained
Defects in Revision Knee Arthroplasty, Clinical Orthopaedics and
Related Research, No. 404, pp. 145-151, Copyright Nov. 2002,
Lippincott Williams & Wilkins, Inc. cited by applicant .
Stryker Howmedica Osteonics, X-change Revision Instruments System,
Copyright Howmedica Osteonics, Sep. 2001. cited by applicant .
U.S. Appl. No. 13/441,154, filed Apr. 6, 2012. cited by applicant
.
International Search Report and Written Opinion for Application No.
PCT/US2012/072087 dated May 2, 2013. cited by applicant .
Extended European Search Report for Application No. EP14159399
dated Jun. 6, 2014. cited by applicant .
Partial International Search Report dated Mar. 15, 2013 for
Application No. PCT/US2012/072087. cited by applicant .
International Search Report and Written Opinion for Application No.
PCT/US2012/068473 dated Mar. 8, 2013. cited by applicant .
Schreurs, et al., Femoral Component Revision with Use of Impaction
Bone-Grafting and a Cemented Polished Stem. Surgical Technique, The
Journal of Bone & Joint Surgery, 2006, pp. 259-274. cited by
applicant .
Knee Revision Product Portfolio, DePuy International Ltd., a
Johnson & Johnson Company, Cat. No. 9075-40-000 version 1,
Copyright 2009. cited by applicant .
Zimmer, Trabecular Metal, Tibial and Femoral Cones Surgical
Techniques, Copyright 2011. cited by applicant.
|
Primary Examiner: Flanagan; Beverly M
Attorney, Agent or Firm: Lerner, David, Littenberg, Krumholz
& Mentlik, LLP
Parent Case Text
CROSS-REFERENCE TO RELATED .[.APPLICATION.].
.Iadd.APPLICATIONS.Iaddend.
This application .Iadd.is a reissue divisional of U.S. application
Ser. No. 15/493,542, filed on Apr. 21, 2017, which is an
application for reissue of U.S. Pat. No. 9,011,444. U.S. Pat. No.
9,011,444 .Iaddend.claims the benefit of the filing date of U.S.
Provisional Patent Application No. 61/568,808, filed Dec. 9, 2011,
the disclosure of which is hereby incorporated .[.herein.]. by
reference.
Claims
The invention claimed is:
.[.1. A surgical system for preparing bone comprising: a reaming
guide assembly including: a trial stem having a proximal end and a
longitudinal axis, the trial stem configured to fit into an
intramedullary canal in the bone, and a guide tube assembly having
a guide tube coupled to the proximal end of the trial stem such
that a longitudinal axis of the guide tube is angled with respect
to the longitudinal axis of the trial stem; and a cannulated reamer
assembly for shaping a bone cavity, the cannulated reamer assembly
having a proximal end, a reaming head coupled at a distal end and a
cannulation extending through the reaming head and distal end
thereof, wherein a longitudinal axis of the cannulated reamer
assembly is angled with respect to the longitudinal axis of the
trial stem when at least a portion of the guide tube is housed
within the cannulation of the cannulated reamer assembly, and
wherein the cannulated reamer assembly is both rotatable about and
slidable along the guide tube during operation..].
.[.2. The surgical system of claim 1, wherein the proximal end of
the cannulated reamer assembly is configured to engage a torque
applying device..].
.[.3. The surgical system of claim 1, wherein the cannulated reamer
assembly further comprises a quick connect mechanism having a ball
detent engaged to a distal end of a reamer shaft, the ball detent
selectively engaging a notch in a proximally protruding extension
of the reaming head in order to couple the reamer shaft to the
reamer head..].
.[.4. The surgical system of claim 1, wherein the reaming guide
assembly further comprises a handle assembly for manipulating the
reaming guide assembly, the handle assembly coupled to the proximal
end of the trial stem such that a surgeon can manipulate the
reaming guide assembly while the trial stem is located in the
intramedullary canal..].
.[.5. The surgical system of claim 4, further comprising an
insertion/removal tool for efficient removal of the reaming guide
assembly from the bone canal, the insertion/removal tool having a
distal end configured for selective engagement to the proximal end
of the trial stem..].
.[.6. The surgical system of claim 4, wherein the guide tube
assembly and the handle assembly are fixed with respect to each
other and are rotatably mounted to the proximal end of the trial
stem such that a surgeon may rotate the guide tube assembly and the
handle assembly about the longitudinal axis of the trial stem while
the guide tube assembly and the handle assembly partially reside
within a central pocket in the bone..].
.[.7. The surgical system of claim 6, further comprising a tibial
implant for implantation into the bone cavity prepared by the
reaming guide and cannulated reamer assemblies, the tibial implant
being shaped to match contours of the bone cavity and having a
central opening defined therethrough, wherein the central opening
is configured to permit the passage of the trial stem or a stem
boss of a tibial baseplate into the intramedullary canal..].
.[.8. The surgical system of claim 7, wherein the shape of the
tibial implant includes at least two outer surfaces being blended
tapered conical surfaces that substantially match the contours of
the bone cavity..].
.[.9. The surgical system of claim 8, wherein the tibial implant
further comprises a proximal surface, a lateral wall, a medial wall
and a fin clearance for positional adjustment of the tibial
baseplate, the fin clearance defines a groove that extends from the
lateral wall through the medial wall and extends through the
proximal surface..].
.[.10. The surgical system of claim 6, further comprising a femoral
implant for implantation into the bone cavity, the femoral implant
being shaped to match contours of the bone cavity and having a
central opening defined therethrough, wherein the central opening
is configured to permit the passage of a femoral stem into the
intramedullary canal..].
.[.11. The surgical system of claim 10, wherein the shape of the
femoral implant includes at least two outer surfaces being tapered
conical surfaces that substantially match the contours of the bone
cavity..].
.[.12. The surgical system of claim 11, wherein the femoral implant
further comprises a posterior wall, an anterior wall and a first
and second clearance space, wherein the first clearance space
defines a recess in the posterior wall shaped to accommodate a
femoral cam box, wherein the second clearance space defines a cut
in anterior wall shaped to accommodate an anterior chamfer of a
femoral implant..].
.[.13. A surgical method for preparing bone comprising the steps
of: placing a reaming guide assembly at least partially into an
already formed intramedullary canal and central pocket that is in
fluid communication with the intramedullary canal, the reaming
guide assembly comprising a trial stem and guide tube assembly, the
trial stem having a proximal end configured to be received in the
intramedullary canal, the guide tube assembly having a guide tube
coupled to the proximal end of the trial stem such that a
longitudinal axis of the guide tube is angled with respect to a
longitudinal axis of the trial stem; coupling a cannulated reamer
assembly to the guide tube assembly such that the proximal end of
the guide tube assembly is housed within a cannulation of the
cannulated reamer assembly and the reaming head contacts bone at a
first position; and driving the cannulated reamer along the guide
tube to a predetermined depth into the bone, thereby forming a
first reamed bone cavity adjacent to the central pocket..].
.[.14. The method of claim 13, wherein the reaming guide assembly
further comprises a handle assembly, the handle assembly being
fixed at the proximal end of the trial stem such that the handle
assembly at least partially resides in the central pocket when the
trial stem is fully seated in the intramedullary canal..].
.[.15. The method of claim 13, wherein the guide tube assembly is
rotatably mounted to the proximal end of the trial stem such that
the guide tube assembly can be rotated about the trial stem from
the first position to a second position..].
.[.16. The method of claim 15, further comprising the step of
rotating the handle assembly and guide tube assembly to the second
position while partially residing within the central pocket..].
.[.17. The method of claim 16, further comprising the step of
reaming bone at the second position with the cannulated reamer
assembly placed over the guide tube assembly, thereby forming a
second reamed bone cavity adjacent to the central pocket..].
.[.18. A method for preparing bone to receive a revision prosthesis
comprising the steps of: reaming the bone generally along an
intramedullary canal with an intramedullary reamer having a
proximal end; placing a cannulated reamer assembly having a reaming
head over the proximal end of the intramedullary reamer such that
the reaming head contacts the bone; driving the cannulated reamer
into bone to a predetermined depth, thereby forming a central bone
pocket; removing the intramedullary reamer and cannulated reamer
assembly from the intramedullary canal and central bone pocket;
placing a reaming guide assembly at least partially into the
intramedullary canal and central bone pocket; wherein the reaming
guide assembly comprises a trial stem, a guide tube assembly, and a
handle assembly, the trial stem having a proximal end and being
configured to fit into the intramedullary canal, the guide tube
assembly having a proximal end and distal end that is rotatably
fixed to the proximal end of the trial stem at an oblique angle
such that the guide tube assembly at least partially resides in the
central bone pocket when the trial stem is fully seated in the
intramedullary canal, the handle assembly being fixed at the
proximal end of the trial stem such that the handle assembly at
least partially resides in the central bone pocket when the trial
stem is fully seated in the intramedullary canal; placing the
cannulated reamer assembly over the proximal end of the guide tube
assembly such that the reaming head contacts bone at a first
position; and driving the cannulated reamer into bone to a
predetermined depth, thereby forming a first bone cavity adjacent
to the central bone pocket..].
.[.19. The method of claim 18, further comprising the step of
rotating the handle assembly and guide tube assembly with respect
to the trial stem while partially residing within the central
pocket to a second position..].
.[.20. The method of claim 19, further comprising the step of
reaming bone at the second position with the cannulated reamer
assembly placed over the guide tube assembly, thereby forming a
second bone cavity adjacent to the central pocket..].
.[.21. The method of claim 13, further comprising: disengaging a
pin located at a distal end of the guide tube assembly from a first
notch disposed at a first location about the trial stem; rotating
the guide tube assembly about the trial stem; and engaging the pin
with a second notch disposed at a second location about the trial
stem..].
.Iadd.22. A method of implanting a tibial prosthesis in a total
knee revision arthroplasty, comprising: removing a previously
implanted tibial prosthesis from a proximal end of a tibia; and
implanting a void filler into the proximal end of the tibia, the
proximal end of the tibia having a bone void previously formed by a
surgical instrument so as to form a central pocket and lateral and
medial pockets blended into the central pocket, the central pocket
and lateral and medial pockets having been formed to correspond to
a geometry of the void filler so that when the void filler is
implanted, a central body of the void filler is received in the
central pocket, lateral and medial members of the void filler are
respectively received in the lateral and medial pockets, and an
opening extending entirely through the central body of the void
filler communicates with an intramedullary canal of the tibia,
wherein the central body and lateral and medial members each have a
curved outer surface that extends about a respective longitudinal
axis, the curved outer surface of each of the lateral and medial
members tapering inwardly from a proximal end of the void filler to
a distal end thereof, the lateral member being integrated into the
central body such that the curved outer surfaces of the lateral
member and the central body meet at an interface between the
lateral member and central body, the interface forms an indented
groove that extends in a proximal-distal direction along an entire
length of the interface..Iaddend.
.Iadd.23. The method of claim 22, further comprising connecting the
void filler to a baseplate component, wherein the void filler is
constructed separately from the baseplate component..Iaddend.
.Iadd.24. The method of claim 23, wherein connecting the void
filler to the baseplate component includes inserting a stem boss of
the baseplate component into the opening extending through the
central body of the void filler..Iaddend.
.Iadd.25. The method of claim 23, wherein connecting the void
filler to the baseplate component includes inserting a tibial stem
through the opening of the central body of the void
filler..Iaddend.
.Iadd.26. The method of claim 25, further comprises implanting the
baseplate component onto the proximal end of the tibia such that
the tibial stem extends from the opening of the central body and
into the intramedullary canal and such that the baseplate component
engages a proximal end of the void filler..Iaddend.
.Iadd.27. A method of implanting a tibial prosthesis in a total
knee revision arthroplasty, comprising: removing a previously
implanted tibial prosthesis from a tibia; forming a bone void in
the tibia at a proximal end thereof so as to form a central portion
and adjacent offset portions of the bone void, the offset portions
joining the central portion and tapering inwardly from the proximal
end of the tibia toward a distal end thereof, wherein forming at
least one of the offset portions of the void includes moving a
cutting tool axially along a longitudinal axis into the bone and
removing the cutting tool from the bone by moving the cutting tool
along the same longitudinal axis, the cutting tool being
constrained to movement along the longitudinal axis; and implanting
a void filler and a revision tibial prosthesis onto the proximal
end of the tibia such that a central body and adjacent offset
members of the void filler are respectively and conformingly
disposed in the central and offset portions of the bone void, and
such that a stem of the revision tibial prosthesis extends through
an opening of the central body and a baseplate component of the
revision tibial prosthesis is positioned adjacent a proximal end of
the void filler and the proximal end of the tibia, wherein the
offset members of the void filler and the central body each define
a longitudinal axis about which a respective curved exterior
surface thereof extends, the longitudinal axes of the offset
members and void filler being offset in a lateral-medial
direction..Iaddend.
.Iadd.28. The method of claim 27, further comprising mechanically
locking the void filler to the revision tibial
prosthesis..Iaddend.
.Iadd.29. The method of claim 27, further comprising inserting bone
cement into a gap between the void filler and the tibial prosthesis
so as to connect the void filler to the tibial
prosthesis..Iaddend.
.Iadd.30. The method of claim 27, further comprising: inserting a
stem boss of the baseplate component of the tibial prosthesis into
the opening of the central body, and engaging a proximal end of the
void filler with the tibial baseplate..Iaddend.
.Iadd.31. The method of claim 27, wherein forming the bone void is
performed by an instrument having bone cutting surfaces that
correspond to the central body and offset members of the void
filler so that a peripheral geometry of the void filler matches
surfaces in the tibia created by the instrument..Iaddend.
.Iadd.32. The method of claim 31, wherein the instrument is a
reamer assembly..Iaddend.
.Iadd.33. The method of claim 27, wherein the offset members are
conically tapered and have a taper greater than a taper of the
central portion..Iaddend.
Description
FIELD OF THE INVENTION
The present invention relates to surgical instruments for preparing
a bone to receive a joint prosthesis system, and in particular
relates to fully guided surgical reaming instruments for use in
total knee replacement revision procedures.
BACKGROUND OF THE INVENTION
Joint replacement surgery is a common orthopedic procedure for
joint such as the shoulder, hip, knee, ankle and wrist. Prior to
implanting prosthetic components in a joint of a patient, a surgeon
generally has to resect at least a portion of the patient's native
bone in order to create a recess or cavity for receiving at least a
portion of the prosthetic components being implanted. During the
process of resecting bone, a surgeon generally only resects the
amount of bone that is needed in order to implant the prosthetic
components in the joint replacement surgery properly. Once native
bone is resected from a joint, it generally can no longer be used
in the joint. Thus, the surgeon attempts to maintain as much native
structural integrity of the joint as he or she can during the
resection process.
When prosthetic components fail for any one of a variety of
reasons, a revision procedure is often necessary. An issue
generally encountered by surgeons replacing joints during a
revision procedure is the loss of native bone near the joint being
replaced. Defects in a bone adjacent a joint, such as the hip or
knee, may occur due to wear and arthritis of the joint, congenital
deformity, and following the removal of a failed prosthetic
component. When the failed prosthetic component or components are
removed from the joint during a revision procedure, it is common
for there to have been further native bone loss in the area
adjacent the original implant position of the prosthetic component
or components. This bone loss is typically due to movement of the
component or components after implantation or even degeneration or
further degeneration of the bone, which can form bone voids that
have unpredictable and non-uniform shapes.
When bone voids are observed in either the proximal tibia or distal
femur, or both, it is standard surgical practice to fill those
voids as part of the surgical procedure. The preferred practice is
to fill those voids with weight bearing void fillers, typically
made of an implant-grade metal such as titanium. These void fillers
may be referred to as metaphyseal reconstruction devices (MRD). The
name MRD more accurately reflects functions such as weight bearing
that these devices provide.
Because the bone voids are typically irregular in shape,
preparation of the bone void area is typically required prior to
implantation of the MRD. This preparation (typically by reaming,
broaching or milling) ensures there is sufficient room in the bone
cavity for the MRD. An accurate fit between the shaped bone cavity
and the MRD is important for establishing joint line, and allowing
for weight bearing and bone remodeling during the recovery
process.
Different methods are commonly used to attempt to prepare the bone
void area to create an accurate fit between the shaped bone cavity
and the MRD. One method is to ream along the intramedullary (IM)
axis, followed by broaching. Another method is to ream on the IM
axis, followed by freehand burr or rongeur bone removal, which may
also be followed by broaching. Problems with these methods include
that reaming is performed on the IM axis only, so that void areas
at a distance from the IM axis, which commonly occur, can only be
resected using manual methods. Moreover, broaching generally has at
least two problems. First, a manual operation can be time
consuming, particularly in cases of sclerotic bone, which exposes
the patient to an increased risk of infection and a longer
recovery. Second, in the case of large bone voids, broaching
generally needs to be performed in a multi-step process because
attempting to remove high volumes of bone in a single broaching
step generally requires high impact forces to the bone. Also,
freehand bone removal, either powered or unpowered, such as by burr
or rongeur, often does not produce accurate cavity shapes to
receive predefined prosthetic components. A typical result is that
areas remain where the outer walls of the MRD do not contact the
cavity, which may lead to undesirable stress distribution and
possible loss of bone regrowth. Also typical is the time consuming
requirement of iterative bone removal, with multiple checks against
the MRD, to obtain a correct fit.
Thus, there is a need for a surgical reaming instrument that
creates accurate bone cavity geometries in minimal time and that
minimizes the necessity for freehand bone removal. There is also a
need for enabling surgeons to create bone cavities with a fully
guided system.
BRIEF SUMMARY OF THE INVENTION
According to one aspect of the present invention, a surgical system
for preparing a bone. The surgical system comprises a reaming guide
assembly, which includes a trial stem having a proximal end and a
longitudinal axis. The trial stem is configured to fit into an
intramedullary canal in the bone. The reaming guide assembly also
comprises a guide tube assembly, which has a distal end portion and
a guide tube that is angled with respect to the distal end portion,
wherein the distal end portion of the guide tube is coupled to the
proximal end of the trial stem such that a longitudinal axis of the
guide tube is angled with respect to the longitudinal axis of the
trial stem. The surgical system further comprises a cannulated
reamer assembly for shaping a bone cavity. The cannulated reamer
assembly has a proximal end, a reaming head coupled at a distal end
and a cannulation extending through the reaming head and distal end
thereof, wherein a longitudinal axis of the cannulated reamer
assembly is angled with respect to the longitudinal axis of the
trial stem when at least a portion of the guide tube is housed
within the cannulation of the cannulated reamer assembly.
In one embodiment, the proximal end of the cannulated reamer
assembly is configured to engage a torque applying device, for
example a drill or manual device.
According to another embodiment, the cannulated reamer assembly
further comprises a quick connect mechanism, which has a ball
detent engaged to a distal end of a reamer shaft. The ball detent
selectively engages a notch in a proximally protruding extension of
the reaming head in order to couple the reamer shaft to the reamer
head.
According to another aspect of the present invention, the reaming
guide assembly further comprises a handle assembly for manipulating
the reaming guide assembly. The handle assembly is coupled to the
proximal end of the trial stem such that a surgeon can manipulate
the reaming guide assembly while the trial stem is located in the
intramedullary canal.
Yet another aspect of the current invention the surgical system
further comprises an insertion/removal tool for efficient removal
of the reaming guide assembly from the bone canal. The
insertion/removal tool has a distal end configured for selective
engagement to the proximal end of the trial stem.
In one embodiment, the guide tube assembly and the handle assembly
are fixed with respect to each other and are rotatably mounted to
the proximal end of the trial stem such that a surgeon may rotate
the guide tube assembly and the handle assembly about the
longitudinal axis of the trial stem while the guide tube assembly
and the handle assembly partially reside within a central pocket in
the bone.
According to another aspect of the current invention, the surgical
system further comprises a tibial implant for implantation into the
reamed bone void created by the reaming guide and cannulated reamer
assemblies. The tibial implant is shaped to match contours of the
bone cavity and has a central opening defined therethrough, wherein
the central opening is configured to permit the passage of the
trial stem or a stem boss of a tibial baseplate into the
intramedullary canal.
The shape of the tibial implant may be realized in the form of at
least two outer surfaces being blended tapered conical surfaces
that substantially match the contours of the bone cavity.
In one embodiment, the tibial implant further comprises a proximal
surface, a lateral wall, a medial wall and a fin clearance for
positional adjustment of the tibial baseplate. The fin clearance
defines a groove that extends from the lateral wall through the
medial wall and extends through the proximal surface.
According to another embodiment of the present invention, the
surgical system further comprises a femoral implant for
implantation into the bone cavity. The femoral implant is shaped to
match contours of the bone cavity and having a central opening
defined therethrough, wherein the central opening is configured to
permit the passage of a femoral stem into the intrameduallry
canal.
The shape of the femoral implant may be realized in the form of at
least two outer surfaces being tapered conical surfaces that
substantially match the contours of the bone cavity.
In one embodiment, the femoral implant further comprises a
posterior wall, an anterior wall and a first and second clearance
space, wherein the first clearance space defines a recess in the
posterior wall shaped to accommodate a femoral cam box, and the
second clearance space defines a cut in anterior wall shaped to
accommodate an anterior chamfer of a femoral implant.
Another aspect of the present invention is a surgical method for
preparing bone. The method comprises placing a reaming guide
assembly at least partially into an already formed intramedullary
canal and an already formed central pocket. The central pocket is
in fluid communication with the intramedullary canal. The reaming
guide assembly comprises a trial stem and guide tube assembly. The
trial stem has a proximal end configured to be received in the
intramedullary canal, and the guide tube assembly has a distal end
portion coupled to the proximal end of the trial stem and a guide
tube angled with respect to the distal end portion. The guide tube
assembly at least partially resides in the central pocket when the
trial stem is fully seated in the intraumeddulary canal. The method
further comprises coupling a cannulated reamer assembly to the
guide tube assembly such that the proximal end of the guide tube
assembly is housed within a cannulation of the cannulated reamer
assembly, and the reaming head contacts bone at a first position.
Further, there is a step of driving the cannulated reamer to a
predetermined depth into the bone, thereby forming a first bone
cavity adjacent to the central pocket.
In one embodiment, the reaming guide assembly further comprises a
handle assembly. The handle assembly being fixed at the proximal
end of the trial stem such that the handle assembly at least
partially resides in the central pocket when the trial stem is
fully seated in the intramedullary canal.
A further aspect of the method comprises the step of manipulating
the handle assembly, thereby placing the reaming guide assembly in
an optimum angular position.
In yet another embodiment, the guide tube assembly and the handle
assembly are fixed with respect to each other and are rotatably
mounted to the proximal end of the trial stem.
According to an additional aspect of the method, the method further
comprises the step of rotating the handle assembly and guide tube
assembly to a second position while partially residing within the
central pocket.
In one embodiment, the method includes a step of reaming bone at
the second position with the cannulated reamer assembly placed over
the guide tube assembly, thereby forming a second bone cavity
adjacent to the central pocket.
According to another embodiment, is a method for preparing bone to
receive a revision prosthesis, which comprises the step of reaming
bone generally along an intramedullary canal with an intramedullary
reamer having a proximal end. Another step of the method is placing
a cannulated reamer assembly having a reaming head over the
proximal end of the intramedullary reamer such that the reaming
head contacts bone. Further, the method includes driving the
cannulated reamer into bone to a predetermined depth, thereby
forming a central bone pocket. The method further comprising
removing the intramedullary reamer and cannulated reamer assembly
from the intramedullary canal and central bone pocket.
Additionally, there is a step of placing a reaming guide assembly
at least partially into the intramedullary canal and central bone
pocket. The reaming guide assembly comprises a trial stem, a guide
tube assembly, and a handle assembly. The trial stem has a proximal
end and is configured to fit into the intramedullary canal.
Further, the guide tube assembly has a proximal end and distal end
that is rotatably fixed to the proximal end of the trial stem at an
oblique angle such that the guide tube assembly at least partially
resides in the central bone pocket when the trial stem is fully
seated in the intramedullary canal. The handle assembly is fixed at
the proximal end of the trial stem such that the handle assembly at
least partially resides in the central bone pocket when the trial
stem is fully seated in the intramedullary canal. Also included is
the step of placing the cannulated reamer assembly over the
proximal end of the guide tube assembly such that the reaming head
contacts bone at a first position. The method further comprises the
step of driving the cannulated reamer into bone to a predetermined
depth, thereby forming a first bone cavity adjacent to the central
bone pocket.
In one embodiment, the method further comprises the step of
rotating the handle assembly and guide tube assembly with respect
to the trial stem while partially residing within the central
pocket to a second position.
According to another aspect of the invention, the method further
comprises the step of reaming bone at the second position with the
cannulated reamer assembly placed over the guide tube assembly,
thereby forming a second bone cavity adjacent to the central
pocket.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1A shows an assembled perspective view of one embodiment of a
surgical reaming instrument of the present invention.
FIG. 1B shows a partially exploded perspective view of the surgical
reaming instrument shown in FIG. 1A with a trial stem separated
therefrom.
FIG. 2A shows an exploded perspective view of a reaming guide the
surgical reaming instrument shown in FIG. 1A.
FIG. 2B shows a partially assembled perspective view of a spring
detent of the reaming guide shown in FIG. 2A with a spring detent
thereof being visible.
FIG. 2C shows an assembled perspective view of the reaming guide
shown in FIG. 2A.
FIG. 3A shows a side view of a reaming guide assembly and a guide
tube assembly.
FIG. 3B shows a cross section view of the reaming guide assembly
and the guide tube assembly taken along line 3B-3B of FIG. 3A.
FIG. 3C shows an enlarged view of an attachment mechanism shown in
FIG. 3B.
FIG. 4A shows a side view of a reaming guide assembly and a guide
tube assembly with a locking rod.
FIG. 4B shows a cross section view of the reaming guide assembly
and the guide tube assembly with locking rod taken along line 4B-4B
of FIG. 4A.
FIG. 5A shows an exploded perspective view of a handle assembly of
one embodiment of the surgical reaming instrument of the present
invention.
FIG. 5B shows a side view of the handle assembly of FIG. 5A.
FIG. 5C shows a cross section view of the handle assembly taken
along line 5C-5C of FIG. 5B.
FIG. 5D shows a perspective view of a handle assembly detached from
a guide body assembly and guide tube assembly.
FIG. 6A shows an exploded perspective view of an insertion/removal
tool for use with a surgical reaming instrument.
FIG. 6B shows a perspective view of an assembled insertion/removal
tool for use with a surgical reaming instrument.
FIG. 6C shows a perspective view of an insertion/removal tool
connected to a surgical reaming instrument.
FIG. 6D shows a side view of an insertion/removal tool connected to
a surgical reaming instrument.
FIG. 6E shows a cross section view of an insertion/removal tool
connected to a surgical reaming instrument taken along line 6E-6E
of FIG. 6D.
FIG. 7A shows a side view of a cannulated reamer assembly.
FIG. 7B shows a cross section view of a cannulated reamer assembly
taken along line 7B-7B of FIG. 7A.
FIG. 7C shows an exploded perspective view of one embodiment of a
cannulated reamer assembly of the present invention.
FIG. 7D shows an assembled perspective view of the cannulated
reamer assembly of FIG. 7C.
FIG. 8A shows a perspective view of a preparatory reaming step in a
tibial bone.
FIG. 8B shows a side view of a preparatory reaming step in a tibial
bone.
FIG. 8C shows a cross section view of the preparatory reaming step
in a tibial bone taken along line 8C-8C of FIG. 8B.
FIG. 9A shows a perspective view of a first reaming step in a
tibial bone using a cannulated reamer assembly.
FIG. 9B shows a side view of a tibial bone after a first reaming
step has been completed.
FIG. 9C shows a cross section view of a tibial bone after a first
reaming step has been completed with a cannulated reaming assembly
taken along line 9C-9C of FIG. 9B.
FIG. 10A shows a perspective view of a surgical reaming instrument
and tibial bone being prepared for a second reaming step.
FIG. 10B shows a perspective view of a surgical reaming instrument
and tibial bone after the second reaming step has been
completed.
FIG. 10C shows a side view of a surgical reaming instrument and
tibial bone after the second reaming step has been completed.
FIG. 10D shows a cross section view of a surgical reaming
instrument and tibial bone after the second reaming step has been
completed taken along line 10D-10D of FIG. 10C.
FIG. 11A shows a side view of a tibial bone after the second
reaming step has been completed.
FIG. 11B shows a cross section view of a tibial bone after the
second reaming step has been completed taken along line 11B-11B of
FIG. 11A.
FIG. 11C shows a side view of a tibial bone after the third reaming
step has been completed.
FIG. 11D shows a cross section view of a tibial bone after the
third reaming step has been completed taken along lien 11-D-11D of
FIG. 11C.
FIG. 11E shows a top view of a tibial bone after the third reaming
step has been completed.
FIGS. 12A-D show different views of one embodiment of a tibial
metaphyseal reconstruction device of the present invention.
FIG. 13A shows a perspective view of the tibial metaphyseal
reconstruction device shown in FIGS. 12A-D prior to implantation
into a tibial bone.
FIG. 13B shows a side view of the tibial bone after a metaphyseal
reconstruction device has been implanted.
FIG. 13C shows a cross section view of the tibial bone after a
metaphyseal reconstruction device has been implanted, taken along
line 13C-13C of FIG. 13B.
FIGS. 14A-D show different views of one embodiment of a femoral
metaphyseal reconstruction device of the present invention.
FIG. 14E shows a perspective view of the femoral metaphyseal
reconstruction device shown in FIGS. 14A-D prior to attachment to a
femoral implant.
FIG. 14F shows a perspective view of the femoral metaphyseal
reconstruction device after attachment to a femoral implant.
DETAILED DESCRIPTION
As used herein, when referring to the surgical reaming instrument
of the present invention, the term "proximal" means closer to the
surgeon or in a direction toward the surgeon and the term "distal"
means more distant from the surgeon or in a direction away from the
surgeon. The term "anterior" means towards the front part of the
body or the face and the term "posterior" means towards the back of
the body. The term "medial" means toward the midline of the body
and the term "lateral" means away from the midline of the body.
FIG. 1A shows a surgical reaming instrument 10. The surgical
reaming instrument 10 generally includes a reaming guide assembly
100, a guide tube assembly 200, a handle assembly 300, and a trial
stem 400, each of which will be described in further detail below.
FIG. 1B shows the surgical reaming instrument 10 with the trial
stem 400 removed from the reaming guide assembly 100.
FIGS. 2A-C show the reaming guide assembly 100 in detail. FIG. 2A
shows an exploded view of the components of the reaming guide
assembly 100. Reaming guide assembly 100 generally includes a
reaming guide 102, a reaming guide collar 104, and a spring detent
116. The reaming guide 102 includes a handle receiving portion 118
and a guide tube receiving portion 124. Reaming guide 102 further
includes a distally projecting extension 106, which is configured
to fit within a hollow proximal portion of the reaming guide collar
104. When the distally projecting extension 106 is within the
hollow proximal portion of the reaming guide collar 104, collar
apertures 114 align with a notch 108 in the distally projecting
extension 106. This allows for reaming guide locking pins 112 to be
placed through collar apertures 114 and sit within the notch 108 in
the distally projecting extension 106. When the locking pins 112
are in place, the reaming guide 102 and the reaming guide collar
104 are restricted from moving distally or proximally with respect
to each other.
FIG. 2B shows a detailed view of spring detent 116 located between
partially assembled reaming guide 102 and reaming guide collar 104.
Referring to FIGS. 2A-B, spring detent 116 includes ridges 128 and
a protrusion 126. Spring detent 116 is generally horseshoe shaped
and surrounds a portion of the distally projecting extension 106
proximal to the notch 108 when the distally projecting extension
106 is within the reaming guide collar 104. The spring detent
protrusion 126 fits into one of apertures 130, 132 on the underside
of the reaming guide 102. Additionally, each ridge 128 in the
spring detent 116 sits within a respective collar notch 110 in the
reaming guide collar 104. When a surgeon or other operating room
personnel inserts the reaming guide 102 into the reaming guide
collar 104, the spring detent protrusion 126 preferably engages the
aperture 130, for instance, and both the spring detent 116 and
reaming guide 102 can be rotated until the ridges 128 engage their
respective collar notches 110. When the ridges 128 engage the
collar notches 110, this engagement can be felt and feedback is
provided to ensure that the reaming guide 102 is in a position such
that locking pin aperture 132 is aligned with another of the collar
notches 110. FIG. 2C shows the reaming guide assembly 100 when
reaming guide 102, reaming guide collar 104 and spring detent 116
are all assembled.
FIGS. 3A-C show detailed views of the guide tube assembly 200
together with the reaming guide assembly 100. FIG. 3A shows a side
view of the reaming assembly 100 and the guide tube assembly 200,
along with section origin 3B.
FIG. 3B shows a cross section of the reaming guide assembly 100 and
guide tube assembly 200 along section origin 3B. FIG. 3C shows an
enlarged view of circular section D from FIG. 3B. Referring to
FIGS. 3B-C, a locking pin 204 is seated partially within the guide
tube receiving portion 124 and further through one of locking pin
apertures 130, 132. The locking pin 204 is surrounded by a coil
spring 206 dimensioned such that the head of locking pin 204 cannot
pass through coil spring 206, and coil spring 206 cannot pass
through locking pin aperture 132. The coil spring 206 and locking
pin 204 are further dimensioned so that when the head of locking
pin 204 is resting on the coil spring 206 with no additional force
applied, the distal end of the locking pin 204 does not enter any
portion of a collar notch 110. Although in FIGS. 3B-C there is no
force being applied to the locking pin 204 other than the weight of
the locking pin 204 itself, the locking pin 204 is shown in the
locked position for purposes of illustration (i.e. the distal end
of the locking pin 204 is within a collar notch 110). The locking
pin 204, when in the locked position, prevents relative rotation
between the reaming guide 102 and the reaming guide collar 104
since the locking pin 204 rests in one of collar notches 110 of
reaming guide collar 104.
Guide tube receiving portion 124 of the reaming guide 102 may
include one or more rinse holes 209 to improve the ability to clean
the surgical reaming instrument 10. Once the locking pin 204 is
seated within the guide tube receiving portion 124 and further
through locking pin aperture 132, a guide tube 202 may be inserted
into the guide tube receiving portion 124. The guide tube 202 may
be permanently fixed within the guide tube receiving portion 124,
for example, by welding. As will be explained in more detail below,
guide tube 202 is used to act as a guide for a cannulated reamer
assembly 600 when reaming a bone.
FIGS. 4A-4B show detailed views of the guide tube assembly 200 and
the reaming guide assembly 100 with locking rod 208 inserted into
guide tube 202. FIG. 4A shows a side view of the reaming assembly
100 and the guide tube assembly 200, along with section origin 4B.
FIG. 4B shows a cross section of the reaming guide assembly 100 and
guide tube assembly 200 along section origin 4B. Locking rod 208 is
inserted into guide tube 202 and can be fixed, for example, by
threading the locking rod 208 into corresponding threads on the
inside of guide tube 202. When the locking rod 208 is fully or
nearly fully inserted into the guide tube 202, a proximal portion
of the locking rod 208 clears the guide tube 202 and provides a
handle 210 for the surgeon to manipulate reaming guide 102. By
rotating the locking rod handle 210, and thus the locking rod 208,
the distal end of the locking rod 208 makes contact with, and
applies force to, the head of the locking pin 204. This rotation
can be continued until the locking pin 204 is fully driven into a
collar notch 110. Once fully driven into the collar notch 110, the
system is in the locked position and the reaming guide 102 is
prevented from rotating relative to the reaming guide collar
104.
FIG. 5A shows an exploded view of the handle assembly 300. FIG. 5B
shows a side view of the handle assembly 300 with section origin
5C. FIG. 5C shows a cross section of the handle assembly 300 along
section origin 5C. FIG. 5D shows the handle assembly 300 fully
assembled and exploded from the remainder of the surgical reaming
instrument 10. Referring now to FIGS. 5A-D, handle assembly 300
generally includes a handle 302, to allow the surgeon to grip the
surgical reaming instrument 10, and an attachment screw 304, to
attach the handle assembly 300 to the reaming guide 102. Alignment
pins 303 are inserted into their respective flanking apertures 122
of the handle receiving portion 118 of the reaming guide 102. These
alignment pins 303 align the screw aperture 306 of the handle
assembly 300 with the center aperture 120 of the handle receiving
portion 118 of the reaming guide 102. Once aligned, the surgeon can
insert the attachment screw 304 into the screw aperture 306 and
further into the center aperture 120 by gripping and rotating the
screw handle 308 so that the attachment screw 304 threads fully
through the screw aperture 306. Once the attachment screw 306 is
fully inserted into the screw aperture 306, the screw collar 315
sits distal to the retaining pin aperture 312. At this point, the
surgeon can insert the screw retaining pin 310 into the retaining
pin aperture 312 such that the screw retaining pin 310 sits
proximal the screw collar 314. This ensures that the attachment
screw 304 is locked into place and cannot exit the screw aperture
306.
FIG. 6A shows an exploded view of an optional insertion/removal
tool 500. FIG. 6B shows a view of the assembled insertion/removal
tool 500. The insertion/removal tool 500 is optionally used to
insert or remove the surgical reaming instrument 10. Referring to
FIGS. 6A-B, an insertion/removal tool 500 generally includes a tool
body 502 and a locking lever 504. Tool body 502 includes a slot 518
into which the locking lever 504 is installed. Locking lever 504
includes an aperture 516 that aligns with pivot pin apertures 514
on each side of the tool body 502. Pivot pin 506 can be inserted
through locking lever aperture 516 and both pivot pin apertures 514
on the tool body 502. The pivot pin 506 allows the locking lever
504 to pivot about the pivot pin 506. Additionally, the proximal
end of the body slot 518 includes a preload spring 508. The preload
spring 508 contacts the locking lever actuator 520. When the
locking lever actuator 520 is pressed, the preload spring 508
compresses and the locking lever 504 pivots about pivot pin 506,
ultimately causing the lever hook 510 to move away form the body
502 of the insertion/removal tool 500. The end of the tool 512 may
optionally be configured to match a universal instrument
handle.
FIG. 6C shows the insertion/removal tool 500 assembled with the
reaming guide assembly 100, the guide tube assembly 200, and the
handle assembly 300. FIG. 6D shows a side view of the illustration
in FIG. 6C along with section origin 6E. FIG. 6E shows a cross
section view of the illustration in FIG. 6D along section origin
6E. Referring to FIGS. 6C-E, the insertion/removal tool 500 can be
slid distally toward the guide body receiving portion 124 of the
reaming guide assembly 100 until the lever hook 510 snaps into a
hook receiving portion 150 of the guide body receiving portion 124
of the reaming guide assembly 100. The preload spring 508 provides
enough force on the proximal end of the locking lever 504 to keep
the insertion/removal tool 500 engaged with the reaming guide
assembly 100. If a surgeon, for instance, desires to detach the
insertion/removal tool 500 from the reaming guide assembly 100, he
simply applies pressure to the locking lever actuator 520 such that
the locking lever 504 pivots about pivot pin 506 and the lever hook
510 disengaged from the reaming guide assembly 100.
FIG. 7A shows a side view of a cannulated reamer assembly 600 with
section origin 7B. Cannulated reamer assembly 600 generally
includes reaming head 602 and reamer shaft assembly 604. Reamer
shaft assembly includes quick connect mechanism 606, shaft handle
607 and drill attachment end 608. The surgeon can grip the quick
connect mechanism 606 and insert the reaming head 602 into the
distal end of the reamer shaft assembly 604 to connect the reaming
head 602 to the reamer shaft assembly 604. To disconnect the
reaming head 602 from the reamer shaft assembly 604, the surgeon
can grip the shaft handle 607 and pull the reamer shaft assembly
604 proximally away from the reaming head 602. The reamer shaft
assembly 604 further includes a drill attachment end 608 on the
proximal end of the reamer shaft assembly 604. The drill attachment
end 608 can be attached to a drill, such as an electric or
pneumatic drill, in order to drive the cannulated reamer assembly
600. Reaming head 602 may include a depth indicator 605, such as a
groove in the reaming head 602, that gives feedback to the surgeon,
such as visual feedback, to notify the surgeon that the reaming
head 602 has traveled a predetermined distance. Reaming head 602
can also contain a tapered distal end 603.
FIG. 7B shows a cross section of the cannulated reamer assembly 600
along the section origin 7B. Reaming head 602 and reamer shaft
assembly 604 both include cannulations 612 that allow the
cannulated reamer assembly 600 to slide over a rod, such as the
guide tube 202 of the guide tube assembly 200 or over the rod of a
traditional intramedullary (IM) reamer. The reaming head 602 also
includes a counterbore 610 to allow the reaming head 602 to clear
the guide tube receiving portion 124 of the reaming guide assembly
100. Additionally, the reamer shaft assembly 604 may include a
viewing port 614 located at the proximal end of the cannulation 612
to give the surgeon visual feedback regarding whether or not the
cannulated reamer assembly 600 has "bottomed out." Essentially, as
long as the rod over which the cannulated reamer assembly 600 is
placed cannot be seen through the view port 614, there is no danger
of "bottoming out." Once the rod can be seen through the view port
614, the surgeon, for instance, can view whether the cannulated
reamer assembly 600 is close to travelling the full distance of
which it is capable before the rod makes contact with the proximal
closed end of the cannulation 612 of the reamer shaft assembly 604.
FIG. 7C shows an exploded view of the cannulated reamer assembly
604 with the reaming head 602 separated from the reamer shaft
assembly 604. FIG. 7D shows the cannulated reamer assembly 604
fully assembled.
An example of one method of use of the invention will now be
described. Referring now to FIGS. 8A-C, the beginning of one method
of a revision procedure is shown. For example, in a revision
procedure of a total knee replacement surgery, the initial step is
to ream the bone 700 generally along the IM canal. Although the IM
reamer 704 is illustrated here as distally reaming the tibia
beginning at the tibial plateau 702, this is merely an example. The
IM reamer 704 could also proximally ream the femur beginning at the
distal end of the femur in substantially the same manner. FIG. 8B
shows the initial step along with section origin 14C, and FIG. 8C
shows a cross section of the initial step along section origin 14C.
As can be seen, the IM reamer 704 enters through the initial bone
void 706 that was originally created during a previous knee
replacement surgery, for example.
FIG. 9A shows the first step following the initial tibial or
femoral IM canal preparation. The IM reamer 704 used to initially
prepare the IM canal is left in place and the cannulation 612 of
the cannulated reaming assembly 600 is placed over the proximal end
of the IM reamer 704. The surgeon then reams over the stem of the
IM reamer 704 using the cannulated reaming assembly 600. The
reaming head 602 is driven distally into the tibial bone until the
surgeon, optionally using the depth indicator 605 as a guide,
determines that the proper depth has been reached based on the
dimensions of a MRD to be implanted into the bone. FIG. 9B shows a
side view of the bone 700 after this reaming step has been
performed, along with section origin 9C. FIG. 9C shows a cross
section of the bone following this reaming step along section
origin 9C. As can be seen, one void space in the bone 700 is the
generally cylindrical preparatory IM reaming void 708 created by
the initial preparation step with the IM reamer 704. A central
pocket 710 created in the initial reaming step corresponds in shape
to the tapered distal end 603 of the reaming head 602.
FIG. 10A shows the reaming guide setup for the second reaming step.
The cannulated reaming assembly 600 first is removed from the IM
reamer 704. Then, the fully assembled reaming guide assembly 100,
guide tube assembly 200, handle assembly 300, and optional
insertion/removal tool 500 are placed near bone 700. FIG. 10B shows
the surgical reaming instrument 10 inserted in the central pocket
710 in the bone after the second reaming step has been completed.
FIG. 10C shows a side view of FIG. 10B along with section origin
10D. FIG. 10D shows a cross section of FIG. 10C along section
origin 10D. Once inserted, as seen in FIG. 10D, the reaming guide
102 makes contact with a portion of the bone 700 surrounding
central pocket 710. The cannulated reaming assembly 600 is then
preferably inserted over the guide tube 202 of the guide tube
assembly 200. The surgeon may use the handle 302 of the handle
assembly 300 for optimum angular positioning of the reaming guide
102. The reaming head 602 of the reaming assembly 600 is then
driven, either manually or with a drill, distally along the guide
tube 202 to ream the bone 700. The reaming guide assembly 100 acts
as a depth stop to ensure that reaming head 602 can only travel a
predetermined distance. Although the counterbore 610 of the reaming
head 602 will pass over the guide tube receiving portion 124 of the
reaming guide assembly 100, the remainder of the reaming guide
assembly 100 will act as a stop for the distal end of the reaming
head 602.
FIG. 11A shows a side view of the bone 700 after the second reaming
step is completed, along with section origin 11B. FIG. 11B shows a
cross section of the bone 700 along section origin 11B. In addition
to the central pocket 710, a medial reaming void 712 preferably
exists along the path taken by the reaming head 602 in the second
reaming step. If necessary, depending on the size and the shape of
the bone void, a third reaming step can be undertaken. With the
surgical reaming instrument 10 in the bone void, the reaming head
602 is moved proximally along the guide tube 202 until it clears
the bone 700. The locking rod handle 210 of the locking rod 208 is
preferably rotated to release the force on the locking pin 204. The
coil spring 206 will cause the locking pin 204 to move proximally
and clear that collar notch 110. Once the locking pin 204 clears
the collar notch 110, the system is in what may be referred to as
an unlocked position and the reaming guide 102 can rotate in
relation to the reaming guide collar 104. One in the unlocked
position, the surgeon can use the handle 302 to rotate the reaming
guide 102 into the desired position for a further reaming step.
Angular stops may be provided in the handle 302 so that angular
rotation between reaming steps can be accurately controlled. Once
in place, the locking rod 208 is manipulated to force the locking
pin 204 back into the locking position so that the third reaming
step can be performed. The third reaming step is preferably
completed in substantially the same manner as the second reaming
step, with the only difference being the portion of the bone 700
being reamed. FIG. 11C shows a side view of the bone 700 after the
third reaming step has been performed, along with section origin
11D. FIG. 11D shows a cross section of the bone 700 along section
origin 11D after the third reaming step has been performed. As can
be seen, in addition to central pocket 710 and medial reaming void
712, there is now a lateral reaming void 714 created as a result of
the third reaming step. FIG. 11E shows a top view of bone 700 after
the third reaming step. The IM axis 720 corresponds to the center
of the central pocket 710 and preparatory IM reaming void 708. The
medial reaming axis 722 corresponds to the center of the medial
reaming void 712, and the lateral reaming axis 724 corresponds to
the center of the lateral reaming void 714. When the reaming is
complete, the bone 700 is ready to receive a void filler prosthetic
component, such as an MRD, for example. In certain embodiments, the
three aforementioned reaming steps do not have to be performed in
any particular order, and in other embodiments, not all three of
the reaming steps are performed.
FIGS. 12A-D show different views of a MRD. In this illustrative
embodiment, the MRD is a tibial MRD .Iadd.or tibial void filler
.Iaddend.800. The tibial MRD 800 is placed within the one or more
reaming voids 710, 712 and 714 in the bone 700. The tibial MRD 800
includes a .Iadd.central body 810 and lateral and medial members
812, 814. Tibial MRD 800 also includes a .Iaddend.central opening
802 .Iadd.that extends through central body 810 .Iaddend.to allow
insertion of a trial stem 400, in this case a tibial stem. The
central opening 802 also allows for insertion of the stem boss of a
tibial baseplate (not shown), the tibial baseplate being engaged to
the proximal side of the tibial MRD 800. The tibial MRD 800 can
also include fin clearances 804 to permit rotation and position
adjustment of the tibial baseplate. .Iadd.Lateral member or lateral
offset member 812 is connected to central body 810 at a lateral
side thereof while medial member or medial offset member 814 is
connected to central body 810 at a medial side thereof. Central
body 810 and lateral and medial members 812, 814 are each conically
shaped and each define a longitudinal axis depicted respectively as
axes A, B, and C which are offset from each other in a
lateral-medial direction, as shown in FIG. 12C. .Iaddend.The outer
surfaces 806 of the tibial MRD 800 are configured to match the
dimensions of surfaces of the bone 700 created by a particular
cannulated reamer assembly 600. In this illustrative embodiment,
outer surfaces 806 include three blended tapered conical surfaces
that match the surface in the bone 700 created by the three reaming
steps described above. .Iadd.In this regard, outer surfaces 806 are
curved surfaces that each extend/curve about longitudinal axis A,
B, or C of the respective central body 810, lateral member 812, and
medial member 814 and taper inwardly from a proximal end to a
distal end of MRD 800. However, since axes B and C are angled
inwardly toward axis A, as shown, curved outer surfaces 806 of
lateral and medial members 812, 814 have a greater taper or slope
than curved surface 806 of central body 810. Longitudinal axes A,
B, and C correspond to the axes 720, 722 and 724 of the void formed
by pockets 710, 712, and 714 shown in FIGS. 11D and 11E such that
when MRD 800 is implanted into such void, axes A, B, and C align
with axes 720, 722, and 724, respectively. Lateral and medial
members 812, 814 are integrated into central body 810 such that the
curved outer surfaces 806 of lateral and medial members 812, 814
respectively meet with outer surface 806 of central body 810 at an
interfaces between the central body 810 and members 812 and 814.
Such interfaces form indentations 808 that each appear as a
longitudinally extending indented groove that extends in a
proximal-distal direction along the entire length of the particular
interface. As shown, lateral and medial members 812, 814 each
interface with central body 810 at two locations such that MRD 800
has four of such indentations 808, as best shown in FIG. 12A.
.Iaddend.
FIG. 13A shows the tibial MRD 800 prior to insertion into the void
in the bone 700 consisting of the central pocket 710, the medial
reaming void 712 and the lateral reaming void 714. FIG. 13B shows a
side view of the bone 700 with the tibial MRD 800 inserted, along
with section origin 13C. FIG. 13C shows a cross section along
section origin 13C of the bone 700 with tibial MRD 800
inserted.
FIGS. 14A-D show, respectively, superior, isometric, anterior, and
lateral views of an MRD. In this illustrative embodiment, the MRD
is a femoral MRD 900. The femoral MRD 900 is generally similar to
the tibial MRD 800, with the main difference being that the femoral
MRD 900 is inserted into the bone void created by a reaming process
on the distal end of the femur. The femoral MRD 900 includes a
central opening 902 to allow for passage of a femoral stem. The
femoral MRD 900 also can include tapered conical surfaces 904 to
correspond to the particular shape of the bone voids created in the
reaming process. Additionally, the femoral MRD 900 can include a
first clearance space 906 for a femoral cam box, if needed, and a
second clearance space 908 for the anterior chamfer of a femoral
implant. FIGS. 14E and 14F show the femoral MRD 900 before and
after attachment to the femoral implant 910, respectively. In this
illustration, the femoral stem is omitted from the femoral stem
attachment site 912 for clarity. The present invention can be used
for multiple types of MRD implantation. For example, cemented MRDs
can be used within the scope of this invention, in which there is a
gap between the MRD and the balance of the implant construct, which
is filled with bone cement during the procedure. Additionally,
locked MRDs can be used within the scope of this invention, in
which a mechanical connection, such as a taper lock, is made
between the MRD and the balance of the implant construct.
There are many benefits of performing a revision procedure with the
surgical reaming instrument of the present invention. For example,
all bone removal steps may be fully guided without the need for any
freehand bone removal. Additionally, the present invention provides
a surgeon with the option of performing a guided ream of the bone
either by hand or by using a powered source, such as a drill.
Further, the instruments generally anatomically match typical bone
voids observed in surgery. For example, the prepared cavity can be
wider in the medial/lateral direction than in the
anterior/posterior direction. Another related benefit is that the
instrument has the capability to prepare asymmetric cavities, such
as larger cavities on the medial side than the lateral side, which
is often seen in cases of tibial bone voids. Importantly, because
of the precision of control allowed when using this instrument, the
shape of the cavity can be precisely controlled which allows for
stock MRDs to accurately fit into the bone void without dependence
on the technique of the particular surgeon performing the surgery.
Related to this is that the symmetric, geometrically defined shape
of the MRD simplifies the setup and machining of void fillers. Yet
another benefit of an embodiment of this invention is that it
allows a cannulated reamer set to consist of differently sized
modular reaming heads and a single shaft to fit all reaming head
sizes. This results in a reduced cost and size of the instrument
set. The MRDs described herein can be made of any biocompatible
material such as polymer and stainless steel, for example.
Although the invention herein has been described with reference to
particular embodiments, it is to be understood that these
embodiments are merely illustrative of the principles and
applications of the present invention. It is therefore to be
understood that numerous modifications may be made to the
illustrative embodiments and that other arrangements may be devised
without departing from the spirit and scope of the present
invention.
* * * * *