Reliance™
CM
Femoral Component
Using the Command™
Instrument
System
Surgical Technique
The
Partnership™ System, which includes the Re1iance™
CM Femoral Component and the Command™
Instruments, is a collaboration between Howmedica
and a group of orthopaedic surgeons and biomedical design engineers.
This team has developed an integrated series of implants and
instruments designed to address the needs of patients, surgeons,
and O.R. staff in today's changing healthcare environment. The
design group includes:
Lester
S. Borden, MD
Head of Adult Reconstructive Surgery
Cleveland Clinic Foundation, Cleveland, OH
Fdward
T. Habermann, MD
Professor and Chairman
Department of Orthopaedic Surgery
Albert Einstein College of Medicine
Orthopaedic Surgeon-in-Chief
Montefiore Medical Center
Albert Einstein College of Medicine, Bronx, NY
Anthony
K. Hedley, MD, FRCS
Chairman, Department of Orthopaedic Surgery
St. Luke's Medical Center, Phoenix, AZ
David
S. Hungerford, MD
Chief, Division of Arthritis Surgery
Professor of Orthopaedic Surgery
Johns Hopkins University, Baltimore, MD
Chief of Orthopaedic Surgery
Good Samaritan Hospital, Baltimore, MD
Kenneth A. Krackow, MD
Professor of Orthopaedic Surgery
State University of New York at Buffalo
Department Head
Department of Orthopaedic Surgery
Buffalo General Hospital, Buffalo, NY
Roger N. Levy, MD
Chief of Arthritis Surgery
Mt. Sinai Medical Center, New York City, NY
Joseph
C. McCarthy, MD
The Department of Orthopaedic Surgery
New Fngland Baptist Hospital, Boston, MA
Associate Clinical Professor
Tufts University School of Medicine, Boston, MA
Philip
C. Noble, PhD
Dunn Professor of Orthopedic Research
The Methodist Hospital, Houston, TX
Hugh
S. Tullos, MD
Wilhelmina Barnhart Chairman
Department of Orthopedic Surgery
Baylor College of Medicine, Houston, TX
Roderick
H. Turner, MD
The Department of Orthopaedic Surgery
New England Baptist Hospital, Boston, MA
Tufts University, Boston, MA
Technique
Options
The
Command™ Instrument System is extremely versatile, offering
surgeons great flexibility in approaching the implantation
of the Reliance™ CM Femoral Component. This publication
presents a basic technique, followed by three appendices.
Appendix I presents options for Starting; Appendix
II presents options for Reaming; and Appendix III presents
Technique Options at-a-Glance, an over view of the
system. These options allow surgeons to customize the Command™
Instrument System to an approach that suits individual preferences
and circumstances.
Preoperative
Templating
The
Re1iance™ CM Hip System offers a complete set of femoral
templates. All templates are at 120% magnification.
Acetabular
Options
Howmedica
offers a wide variety of acetabular components that are compatible
with the Re1iance™ CM Femoral Component. The surgeon
should refer to a specific acetabular component's surgical
technique for a discussion of acetabular surgical procedures.
Surgical
Approach
Each
surgeon should use the surgical approach for total hip arthroplasty
with which he is most familiar. Patient positioning, prepping
and draping, the skin incision, soft tissue dissection, and
hip dislocation are performed according to the surgeon's preferred
technique, making certain to adequately expose the acetabulum
and the proximal femur.
This
publication sets forth recommended procedures for using Howmedica
devices and instruments. It offers guidance that you should
heed, but, as with any such technical guide, each surgeon
must consider the particular needs of each patient and make
appropriate adjustments when and as required.
*Command:
Patents Pending.
STARTING*
Determine
and Mark the Osteotomy Level
By
using anatomic landmarks identified during templating, the
osteotomy guide identifies the location of the osteotomy cut.
The osteotomy guide has several features to assist the surgeon:
- [A]Long
tail of the osteotomy guide for alignment with the femoral
shaft axis.
- [B]Notch
in the proximal portion of the guide references the proximal
tip of the greater trochanter.
- [C]Location
holes determine the center of rotation for the head position
options available for stem size.
Care
must be taken to restore proper leg length by referencing the
osteotomy level back to the center of rotation of the implanted
acetabular component. The resection level, relative to the lesser
trochanter, should be about a fingerbreadth above. Angled surface
provides a plane for marking the level of the cut, or can be
used as a cutting surface for the sawblade.
Perform
Osteotomy
40°
osteotomy angle allows single cut across the neck, and generally
eliminates the need for a second cut to complete the resection.
*Additional
options availble; see Appendix 1.
Open
and Size the Canal with Starter Awl
The
tapered starter awl is a hand-operated instrument designed
to open the femoral canal and indicate distal diameter size.
Assemble small hex T-handle onto starter/sizer awl,
and target piriformis fossa to open canal. Progress the awl
distally until some cortical resistance is achieved. Use aggressive
cutting teeth of starter awl to achieve lateralization.
Depth
of Starter Awl
Make
note of millimeter diameter marking that appears at the medial
osteotomy level. These markng grooves on shaft identify distal
diameter sizing of femoral canal.
REAMING*
Assemble
and Introduce Straight Reamer
Assemble
a power adaptor or large hex T-handle, if preferred,
to the straight, cylindrical reamer. Select diameter of reamer
based on starter awl diameter reading, starting with a size
one or two millimeters smaller.
Use
of the Straight Reamer and Depth Markings
Ensure
the reamer is directed laterally and into a neutral position.
Insert reamer until the most proximal depth marking groove
is aligned with the medial edge of the osteotomy.
NOTE:
When lateralizing rigid reamers, take care to properly
retract/protect the abductor muscle fibers of the gluteus
minimus/medius at the superior tip of the greater trochanter.
*Additional
options available; see Appendix II.
BROACHING
Select
Fully Toothed Broach
There
are two styles of broaches available: Fully Toothed (cemented)
and Universal. The Fully Toothed broach is featured
here. Select a broach one size smaller than the anticipated
implant size, based on preoperative templating. Attach handle
to broach by inserting trunnion of the broach into broach
handle and turning the locking knob in the direction indicated.
Introduce
Broach
Introduce
broach into proximal femur. Drive the broach down the canal
with a mallet, keeping it aligned with the neutral femoral
axis. Assess fit and resistance to movement. If
a larger size is needed, remove the broach and replace it
with the next size. To facilitate final seating of the broach,
partially withdraw the broach to clear cutting teeth of bone;
then re-introduce the instrument into the canal.
Calcar
Planer
Leave
the final broach seated in the canal. Remove the broach handle.
The broach trunnion may be used as a guide for the calcar
planer. The calcar planers come in two sizes: standard and
large. Select the proper size planer and assemble to power
adaptor. The female bushing on the planer is guided over the
broach trunnion. The medial calcar should be leveled to aid
the collar calcar contact.
Fit
Neck Trial to Trunnion
Disassemble
the broach handle, and select appropriate size neck trial
corresponding to broach/implant size, and push the trunnion
securely onto the broach.
COMPLETION
Attach
Head Trial
Select
the head diameter [26mm, 28mm, or 32mm] according to surgeon
preference. The head trials have a circumferential groove
which identifies the level of the center of rotation. Select
neck length: -4mm, *Std., +4mm, +8mm, +12mm, +l6mm** based
on preoperative templating. Attach the head trial to the neck
trial and perform a trial reduction, assessing the hip for
stability, leg length, and over all range of motion. Remove
the broach and all trials.
*NOTE:
+16mm is only suitable for stem sizes #4 and above; -4mm
is not available in 26mm head sizes. Refer to sizing chart
on page 19.
Insert
Cement
Thoroughly
clean and dry the canal. Insert a bone plug to a level 20mm
distal to end of stem. Prepare the bone cement. Pump cement
into the canal in retrograde fashion, retracting the nozzle
as back pressure is felt. When the canal is filled with cement,
place the appropriate pressurizing seal in the mouth of femur.
Slide the cement nozzle through the seal and introduce remaining
cement under pressure. Retain a small bolus of bone cement
to serve as guide when the cement in the canal has cured.
Assemble
Introducer to Implant
Assemble
the insertion tool to the implant. Make sure that the distal
tip of the instrument is correctly mated to the orientation
keyway of the insertion feature of the implant. For ease
of assembly, hold the hands as illustrated in the photograph
at right, using the thumb to turn the locking knob. Fully
and securely attach the instrument to the stem.
Select
and Attach Distal Spacer
The
correct size of the distal centralizer is deterined by the
diameter of the distal canal. Each centralizer will fit into
the distal hole of any stem size and is held in place via
taper lock. The distal centralizer will guide the Reliance
into neutral alignment during insertion.
Insert
the Implant
Insert
the implant. The handle can be used to control anteversion
as you implant the prosthesis. Remove the inserter by turning
the locking knob on the top of the stem inserter.
Final
Trial Reduction
A
head trial can be placed onto the implant and a final trial
reduction performed.
Impact
Head onto Stem
Select
appropriate size Howmedica V40™ femoral head, wipe trunnion
clean, and impact head on trunnion with femoral head impactor.
NOTE: Only Howmedica V40™ femoral heads labeled
as 5° 40' taper may be used with the stems in this
system.
Reduce
Joint and Close
Relocate
the femoral head into the acetabular cup and check the laxity
and range of motion. The surgical site is then closed according
to the surgeon's standard procedure for the surgical approach
chosen.
APPENDIX
I
STARTING
OPTIONS
The
Starter Kit has three technique options to open and size the
femoral canal. The options contain both standard and new methods
to gain access to the femoral canal and to ensure a neutral/lateral
start for each subsequent instrument.
Starting
Option 1: Starter
Awl (Presented in Basic Technique)
Open
and Size the Canal with Starter Awl
The
tapered starter awl is a hand-operated instrument designed
to open the femoral canal and indicate distal diameter size.
Assemble small hex T-handle onto starter/sizer awl,
and target pin formis fossa to open canal. Progress the awl
distally until some cortical resistance is achieved. Use aggressive
cutting teeth of starter awl to achieve lateralization.
Depth
of Starter Awl
Make
note of millimeter diameter marking that appears at the medial
osteotomy level. These marking grooves on shaft identify distal
diameter sizing of femoral canal.
Starting
Option 2:
Box
Chisel
There
are three sizes of the box chisels: the small size
corresponds to the Reliance™ CM femoral implant size
#1; the medium to sizes #2 to #5.
Box
Chisel Technique Variation A
The
box chisel may be used to open the proximal femur prior to
use of the tapered starter/sizer awl. After the osteotomy
has been performed, the appropriate size box chisel is selected
and introduced into the axis of the femoral shaft, starting
lateral to the cortex of the neck. This will remove a wedge
of bone at the medial base of the greater trochanter, helping
to achieve neutral/lateral alignment of the tapered starter/sizer
awl.
Box
Chisel Technique with Box Chisel Guide Variation B
The
box chisel may also be used with the sharp trochar point box
chisel guide. Assemble the box chisel guide to the box chisel
by threaded engagement. The box chisel guide is inserted into
the long axis of the femur, targeting the piriformis fossa;
the guide will serve to direct/align the box chisel cutting
head.
Box
Chisel Technique with the Starter Awl Variation C
The
box chisel may also be used with the tapered starter/sizer
awl. After the awl has been used to open and size the femoral
canal, the small hex T-handle may be removed with the
awl engaged in the isthmus of the femoral canal. The shaft
of the awl may now be used as an axial guide coinciding with
the long axis of the femur. The box chisel is cannulated so
that it slides over the shaft of the awl, removing a wedge
of bone at the medial base of the greater trochanter.
Starting
Option 3:
Proximal Reamer Sleeves
with the Starter Awl
The
System's proximal reamer sleeves come in three sizes. Those
applicable to the Reliance™ CM femoral components are:
small (#1) and medium (#2-#5). After the tapered
starter awl has been used to open and size the distal femoral
canal, remove it from the femur and assemble the appropriate
size proximal reamer sleeve. Re-introduce the assembly of
the proximal reamer sleeve and awl distally into the femoral
canal. Lateralize the proximal reamer sleeve to manually groove
out the medial aspect of the greater trochanter. The depth
of insertion has been established in the previous step. The
intent of the proximal reamer sleeve is to attain neutral
alignment by lateralizing into the greater trochanter.
NOTE:
When lateralizing rigid reamers, take care to properly retract/protect
the abductor muscle fibers of the gluteus mininus/medius at
the superior tip of the greater trochanter.
APPENDIX
II
Reaming
Options
Presented
here are five technique options for Reaming the femoral
canal, using the Command™ Instrument System:
Option 1: Straight Reamer
Option 2: Gray™
Fixed Head IM Flexible Reamer
Option 3: Gray™
Fixed Head IM Flexible Reamer and Proximal-Conical/Distal-Bullet
Reamer
Option 4: Straight Reamer and Proximal-Conical/Distal-Bullet
Reamer
Option 5: Proximal-Distal Baton Reamer
An
alternative approach is to omit the medullary reaming stage
altogether. The femoral canal may be prepared by simply using
the starter options and fully toothed broaches.
Reaming
Option 1:
Straight Reamer
Assemble
and Introduce Straight Reamer
Assemble
a power adaptor or large hex T-handle, if preferred,
to the straight, cylindrical reamer. Select diameter of reamer
based on starter awl diameter reading, starting with a size
one or two millimeters smaller.
Use
of the Straight Reamer and Depth Markings
Ensure
the reamer is directed laterally and into a neutral position.
Insert reamer until the most proximal depth marking groove is
aligned with the medial edge of the osteotomy.
NOTE:
When lateralizing rigid reamers, take care to properly retract/protect
the abductor muscle fibers of the gluteus minimus/medius at
the superior tip of the greater trochanter.
Reaming
Option 2:
Gray™ Fixed Head IM
Flexible Reamer
Gray™
Fixed Head IM Flexible Reamer
To
prepare the cylindrical, distal diameter using flexible reamers
rather than straight cylindrical reamers, select diameter
of reamer based on starter awl diameter reading. Start with
a size one or two millimeters smaller.
Reaming
Option 3:
Gray™ Fixed Head IM Flexible Reamer and
Proximal-Conical/ Distal-Bullet Reamer
Gray™
Fixed Head IM Flexible Reamer
To
prepare the cylindrical, distal diameter using flexible reamers
rather than straight cylindrical reamers, select diameter of
reamer based on starter awl diameter reading. Start with a size
one or two millimeters smaller.
Select
Proxima1-Conical/Distal-Bullet Reamer
Select
proximal-conical/distal-bullet reamer corresponding to the
size of the implant determined by preoperative templating
and the preceding cylindrical reaming. Each size implant has
a correponding proximal-conical/ distal-bullet reamer. These
reamers have the large hex drive fitting, which can
be attached to the power adaptor or used with the large manual
T-handle.
Position
Distal-Bullet Reamer and Gauge Depth
Insert
proximal-conical/distal-bullet reamer into the canal, maintaining
neutral/lateral alignment and achieving lateralization. Insert
reamer until the most proximal depth marking groove is aligned
with the medial edge of the osteotomy.
Reaming
Option 4:
Straight Reamer and Proximal-Conical/Distal-Bullet
Reamer
Assemble
and Introduce Straight Reamer
Assemble
a power adaptor or large hex T-handle, if preferred,
to the straight, cylindrical reamer. Select diameter of reamer
based on starter awl diameter reading, starting with a size
one or two millimeters smaller.
Use of the Straight Reamer and Depth Markings
Ensure
the reamer is directed laterally and into a neutral position.
Insert reamer until the most proximal depth marking groove
is aligned with the medial edge of the osteotomy.
NOTE:
When lateralizing rigid reamers, take care to properly
retract/protect the abductor muscle fibers of the gluteus
minimus/medius at the superior tip of the greater trochanter.
Select
Proximal-Conical/Distal-Bullet Reamer
Select
proximal-conical/distal-bullet reamer corresponding to the size
of the implant determined by preoperative templating and the
preceding cylindrical reaming. Each size implant has a corre
sponding proximal-conical/distal-bullet reamer. These reamers
have the large hex drive fitting, which can be attached
to the power adaptor or used with the large manual T-handle.
Position
Proximal-Conical/Distal-Bullet Reamer and Gauge
Depth
Insert
proximal-conical/distal-bullet reamer into the canal, maintaining
neutral/lateral alignment and achieving lateralization. Insert
reamer until the most proximal depth marking groove is aligned
with the medial edge of the osteotomy.
Reaming
Option 5:
Proximal-Distal Baton Reamer
Proximal-Distal
Baton Reamer
The
proximal-distal baton reamer is designed to combine the distal
cutting of the straight IM reamer and the proximal cutting
of the proximal-conical/distal-bullet reamer. [This reamer
is also known as the ONE-STEP reamer.]
Introduce
Proximal-Distal Baton Reamer
Assemble
a power adapter or large hex T-handle, if preferred, to the
proximal-distal baton reamer. Select the reamer that corresponds
to the implant size as determined by preoperative templating
and the distal diameter of the femoral canal as determined
by the tapered starter/sizer awl. Each size implant has a
corresponding proximal-distal baton reamer that will simultaneously
prepare the distal diameter and proximal-conical region of
the femoral canal. Insert proximal-distal baton reamer into
the canal, maintaining neutral/lateral align ment and achieving
lateralization. Advance the reamer distally until the depth
marking groove is aligned with the medial edge of the osteotomy.
Reliance™
CM Femoral Component
Stem
Size
Stem
Length
Minimum
Distal
Canal Diameter
Required
Neck
Angle
#1
100mm
11mm
132°
#2
115mm
l2mm
#3
13mm
#4
125mm
14mm
#5
15mm
Neck
Length*
Stem
Size
Short**
-4m
Standard
0mm
Medium
+4mm
Long
+8mm
X-Long
+12mm
XX-Long
+16mm
#1
27mm
31mm
35mm
39mm
43mm
N/A
#2
28mm
32mm
36mm
40mm
44mm
N/A
#3
30mm
34mm
38mm
42mm
46mm
N/A
#4
31mm
35mm
39mm
43mm
47mm
51mm
#5
33mm
37mm
41mm
45mm
49mm
53mm
Femoral
Head Offset*
Stem
Size
Short**
-4mm
Standard
Omm
Medium
+4mm
Long
+8mm
X-Long
+l2mm
XX-Long
+16mm
#1
31mm
34mm
37mm
40mm
43mm
N/A
#2
33mm
36mm
39mm
42mm
45mm
N/A
#3
37mm
40mm
43mm
46mm
49mm
N/A
#4
41mm
44mm
47mm
50mm
53mm
56mm
#5
44mm
47mm
50mm
53mm
56mm
59mm
*Heads
avai1ab1e in 26mm, 28mm, and 32mm diameters.
**Not available in 26mm diameter head.
APPENDIX
III
Technique
Options at-a-Glance
The
Command™
Instrument System offers great flexibility when approaching
implantation of the Reliance™
CM Femoral Component.
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Reliance™
CM
Femoral Component
Using the Command™ Instrument System Surgical Technique The
Partnership™ System, which includes the Re1iance™
CM Femoral Component and the Command™
Instruments, is a collaboration between Howmedica
and a group of orthopaedic surgeons and biomedical design engineers.
This team has developed an integrated series of implants and
instruments designed to address the needs of patients, surgeons,
and O.R. staff in today's changing healthcare environment. The
design group includes:
Lester
S. Borden, MD Fdward
T. Habermann, MD Anthony
K. Hedley, MD, FRCS David
S. Hungerford, MD Joseph
C. McCarthy, MD Philip
C. Noble, PhD Hugh
S. Tullos, MD Roderick
H. Turner, MD
The Command™ Instrument System is extremely versatile, offering surgeons great flexibility in approaching the implantation of the Reliance™ CM Femoral Component. This publication presents a basic technique, followed by three appendices. Appendix I presents options for Starting; Appendix II presents options for Reaming; and Appendix III presents Technique Options at-a-Glance, an over view of the system. These options allow surgeons to customize the Command™ Instrument System to an approach that suits individual preferences and circumstances. Preoperative Templating The Re1iance™ CM Hip System offers a complete set of femoral templates. All templates are at 120% magnification. Acetabular Options Howmedica offers a wide variety of acetabular components that are compatible with the Re1iance™ CM Femoral Component. The surgeon should refer to a specific acetabular component's surgical technique for a discussion of acetabular surgical procedures. Surgical Approach Each surgeon should use the surgical approach for total hip arthroplasty with which he is most familiar. Patient positioning, prepping and draping, the skin incision, soft tissue dissection, and hip dislocation are performed according to the surgeon's preferred technique, making certain to adequately expose the acetabulum and the proximal femur. This publication sets forth recommended procedures for using Howmedica devices and instruments. It offers guidance that you should heed, but, as with any such technical guide, each surgeon must consider the particular needs of each patient and make appropriate adjustments when and as required. *Command: Patents Pending.
Determine and Mark the Osteotomy Level By
using anatomic landmarks identified during templating, the
osteotomy guide identifies the location of the osteotomy cut.
The osteotomy guide has several features to assist the surgeon:
Care must be taken to restore proper leg length by referencing the osteotomy level back to the center of rotation of the implanted acetabular component. The resection level, relative to the lesser trochanter, should be about a fingerbreadth above. Angled surface provides a plane for marking the level of the cut, or can be used as a cutting surface for the sawblade. Perform Osteotomy 40° osteotomy angle allows single cut across the neck, and generally eliminates the need for a second cut to complete the resection. *Additional options availble; see Appendix 1.
Open and Size the Canal with Starter Awl The
tapered starter awl is a hand-operated instrument designed
to open the femoral canal and indicate distal diameter size.
Assemble small hex T-handle onto starter/sizer awl,
and target piriformis fossa to open canal. Progress the awl
distally until some cortical resistance is achieved. Use aggressive
cutting teeth of starter awl to achieve lateralization. Depth of Starter Awl Make note of millimeter diameter marking that appears at the medial osteotomy level. These markng grooves on shaft identify distal diameter sizing of femoral canal.
Assemble and Introduce Straight Reamer Assemble a power adaptor or large hex T-handle, if preferred, to the straight, cylindrical reamer. Select diameter of reamer based on starter awl diameter reading, starting with a size one or two millimeters smaller. Use of the Straight Reamer and Depth Markings Ensure the reamer is directed laterally and into a neutral position. Insert reamer until the most proximal depth marking groove is aligned with the medial edge of the osteotomy. NOTE: When lateralizing rigid reamers, take care to properly retract/protect the abductor muscle fibers of the gluteus minimus/medius at the superior tip of the greater trochanter. *Additional options available; see Appendix II.
Select Fully Toothed Broach There are two styles of broaches available: Fully Toothed (cemented) and Universal. The Fully Toothed broach is featured here. Select a broach one size smaller than the anticipated implant size, based on preoperative templating. Attach handle to broach by inserting trunnion of the broach into broach handle and turning the locking knob in the direction indicated. Introduce Broach Introduce broach into proximal femur. Drive the broach down the canal with a mallet, keeping it aligned with the neutral femoral axis. Assess fit and resistance to movement. If a larger size is needed, remove the broach and replace it with the next size. To facilitate final seating of the broach, partially withdraw the broach to clear cutting teeth of bone; then re-introduce the instrument into the canal.
Calcar Planer Leave the final broach seated in the canal. Remove the broach handle. The broach trunnion may be used as a guide for the calcar planer. The calcar planers come in two sizes: standard and large. Select the proper size planer and assemble to power adaptor. The female bushing on the planer is guided over the broach trunnion. The medial calcar should be leveled to aid the collar calcar contact. Fit Neck Trial to Trunnion Disassemble the broach handle, and select appropriate size neck trial corresponding to broach/implant size, and push the trunnion securely onto the broach.
Attach Head Trial Select the head diameter [26mm, 28mm, or 32mm] according to surgeon preference. The head trials have a circumferential groove which identifies the level of the center of rotation. Select neck length: -4mm, *Std., +4mm, +8mm, +12mm, +l6mm** based on preoperative templating. Attach the head trial to the neck trial and perform a trial reduction, assessing the hip for stability, leg length, and over all range of motion. Remove the broach and all trials. *NOTE: +16mm is only suitable for stem sizes #4 and above; -4mm is not available in 26mm head sizes. Refer to sizing chart on page 19. Insert Cement Thoroughly clean and dry the canal. Insert a bone plug to a level 20mm distal to end of stem. Prepare the bone cement. Pump cement into the canal in retrograde fashion, retracting the nozzle as back pressure is felt. When the canal is filled with cement, place the appropriate pressurizing seal in the mouth of femur. Slide the cement nozzle through the seal and introduce remaining cement under pressure. Retain a small bolus of bone cement to serve as guide when the cement in the canal has cured.
Assemble Introducer to Implant Assemble the insertion tool to the implant. Make sure that the distal tip of the instrument is correctly mated to the orientation keyway of the insertion feature of the implant. For ease of assembly, hold the hands as illustrated in the photograph at right, using the thumb to turn the locking knob. Fully and securely attach the instrument to the stem. Select and Attach Distal Spacer The correct size of the distal centralizer is deterined by the diameter of the distal canal. Each centralizer will fit into the distal hole of any stem size and is held in place via taper lock. The distal centralizer will guide the Reliance into neutral alignment during insertion. Insert the Implant Insert the implant. The handle can be used to control anteversion as you implant the prosthesis. Remove the inserter by turning the locking knob on the top of the stem inserter.
Final Trial Reduction A head trial can be placed onto the implant and a final trial reduction performed. Impact Head onto Stem Select
appropriate size Howmedica V40™ femoral head, wipe trunnion
clean, and impact head on trunnion with femoral head impactor. Reduce Joint and Close Relocate the femoral head into the acetabular cup and check the laxity and range of motion. The surgical site is then closed according to the surgeon's standard procedure for the surgical approach chosen.
The Starter Kit has three technique options to open and size the femoral canal. The options contain both standard and new methods to gain access to the femoral canal and to ensure a neutral/lateral start for each subsequent instrument. Starting Option 1: Starter Awl (Presented in Basic Technique)
Open and Size the Canal with Starter Awl The tapered starter awl is a hand-operated instrument designed to open the femoral canal and indicate distal diameter size. Assemble small hex T-handle onto starter/sizer awl, and target pin formis fossa to open canal. Progress the awl distally until some cortical resistance is achieved. Use aggressive cutting teeth of starter awl to achieve lateralization. Depth of Starter Awl
Make note of millimeter diameter marking that appears at the medial osteotomy level. These marking grooves on shaft identify distal diameter sizing of femoral canal.
Starting
Option 2:
Box
Chisel There are three sizes of the box chisels: the small size corresponds to the Reliance™ CM femoral implant size #1; the medium to sizes #2 to #5. Box Chisel Technique Variation A The box chisel may be used to open the proximal femur prior to use of the tapered starter/sizer awl. After the osteotomy has been performed, the appropriate size box chisel is selected and introduced into the axis of the femoral shaft, starting lateral to the cortex of the neck. This will remove a wedge of bone at the medial base of the greater trochanter, helping to achieve neutral/lateral alignment of the tapered starter/sizer awl. Box Chisel Technique with Box Chisel Guide Variation B The box chisel may also be used with the sharp trochar point box chisel guide. Assemble the box chisel guide to the box chisel by threaded engagement. The box chisel guide is inserted into the long axis of the femur, targeting the piriformis fossa; the guide will serve to direct/align the box chisel cutting head. Box Chisel Technique with the Starter Awl Variation C The box chisel may also be used with the tapered starter/sizer awl. After the awl has been used to open and size the femoral canal, the small hex T-handle may be removed with the awl engaged in the isthmus of the femoral canal. The shaft of the awl may now be used as an axial guide coinciding with the long axis of the femur. The box chisel is cannulated so that it slides over the shaft of the awl, removing a wedge of bone at the medial base of the greater trochanter.
Starting Option 3: Proximal Reamer Sleeves with the Starter Awl The System's proximal reamer sleeves come in three sizes. Those applicable to the Reliance™ CM femoral components are: small (#1) and medium (#2-#5). After the tapered starter awl has been used to open and size the distal femoral canal, remove it from the femur and assemble the appropriate size proximal reamer sleeve. Re-introduce the assembly of the proximal reamer sleeve and awl distally into the femoral canal. Lateralize the proximal reamer sleeve to manually groove out the medial aspect of the greater trochanter. The depth of insertion has been established in the previous step. The intent of the proximal reamer sleeve is to attain neutral alignment by lateralizing into the greater trochanter. NOTE: When lateralizing rigid reamers, take care to properly retract/protect the abductor muscle fibers of the gluteus mininus/medius at the superior tip of the greater trochanter.
Presented
here are five technique options for Reaming the femoral
canal, using the Command™ Instrument System: An alternative approach is to omit the medullary reaming stage altogether. The femoral canal may be prepared by simply using the starter options and fully toothed broaches.
Assemble
and Introduce Straight Reamer Assemble
a power adaptor or large hex T-handle, if preferred,
to the straight, cylindrical reamer. Select diameter of reamer
based on starter awl diameter reading, starting with a size
one or two millimeters smaller. Use
of the Straight Reamer and Depth Markings Ensure the reamer is directed laterally and into a neutral position. Insert reamer until the most proximal depth marking groove is aligned with the medial edge of the osteotomy. NOTE: When lateralizing rigid reamers, take care to properly retract/protect the abductor muscle fibers of the gluteus minimus/medius at the superior tip of the greater trochanter. Reaming
Option 2:
Gray™ Fixed Head IM Gray™ Fixed Head IM Flexible Reamer
To prepare the cylindrical, distal diameter using flexible reamers rather than straight cylindrical reamers, select diameter of reamer based on starter awl diameter reading. Start with a size one or two millimeters smaller. Reaming Option 3: Gray™ Fixed Head IM Flexible Reamer and Proximal-Conical/ Distal-Bullet Reamer Gray™ Fixed Head IM Flexible Reamer
To prepare the cylindrical, distal diameter using flexible reamers rather than straight cylindrical reamers, select diameter of reamer based on starter awl diameter reading. Start with a size one or two millimeters smaller.
Select Proxima1-Conical/Distal-Bullet Reamer Select proximal-conical/distal-bullet reamer corresponding to the size of the implant determined by preoperative templating and the preceding cylindrical reaming. Each size implant has a correponding proximal-conical/ distal-bullet reamer. These reamers have the large hex drive fitting, which can be attached to the power adaptor or used with the large manual T-handle.
Position Distal-Bullet Reamer and Gauge Depth Insert proximal-conical/distal-bullet reamer into the canal, maintaining neutral/lateral alignment and achieving lateralization. Insert reamer until the most proximal depth marking groove is aligned with the medial edge of the osteotomy. Reaming Option 4: Straight Reamer and Proximal-Conical/Distal-Bullet Reamer Assemble and Introduce Straight Reamer
Assemble a power adaptor or large hex T-handle, if preferred, to the straight, cylindrical reamer. Select diameter of reamer based on starter awl diameter reading, starting with a size one or two millimeters smaller.
Ensure the reamer is directed laterally and into a neutral position. Insert reamer until the most proximal depth marking groove is aligned with the medial edge of the osteotomy. NOTE: When lateralizing rigid reamers, take care to properly retract/protect the abductor muscle fibers of the gluteus minimus/medius at the superior tip of the greater trochanter. Select Proximal-Conical/Distal-Bullet Reamer
Select proximal-conical/distal-bullet reamer corresponding to the size of the implant determined by preoperative templating and the preceding cylindrical reaming. Each size implant has a corre sponding proximal-conical/distal-bullet reamer. These reamers have the large hex drive fitting, which can be attached to the power adaptor or used with the large manual T-handle. Position Proximal-Conical/Distal-Bullet Reamer and Gauge Depth
Insert proximal-conical/distal-bullet reamer into the canal, maintaining neutral/lateral alignment and achieving lateralization. Insert reamer until the most proximal depth marking groove is aligned with the medial edge of the osteotomy. Reaming Option 5: Proximal-Distal Baton Reamer Proximal-Distal Baton Reamer
The proximal-distal baton reamer is designed to combine the distal cutting of the straight IM reamer and the proximal cutting of the proximal-conical/distal-bullet reamer. [This reamer is also known as the ONE-STEP reamer.] Introduce Proximal-Distal Baton Reamer
Assemble a power adapter or large hex T-handle, if preferred, to the proximal-distal baton reamer. Select the reamer that corresponds to the implant size as determined by preoperative templating and the distal diameter of the femoral canal as determined by the tapered starter/sizer awl. Each size implant has a corresponding proximal-distal baton reamer that will simultaneously prepare the distal diameter and proximal-conical region of the femoral canal. Insert proximal-distal baton reamer into the canal, maintaining neutral/lateral align ment and achieving lateralization. Advance the reamer distally until the depth marking groove is aligned with the medial edge of the osteotomy.
Reliance™ CM Femoral Component
*Heads
avai1ab1e in 26mm, 28mm, and 32mm diameters.
The Command™ Instrument System offers great flexibility when approaching implantation of the Reliance™ CM Femoral Component.
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