TaperFit™

TaperFit™
Cemented Total Hip Replacement
Surgical technique
TaperFit™
Contents
Operative summary
4
Pre-operative templating
5
Surgical exposure
5
Femoral neck resection
5
Acetabular preparation
5
Cenator cup acetabular preparation and implantation
6
Reaming the acetabulum
6
Insertion of the acetabular cup
6
TaperFit femoral preparation
7
Opening the femur
7
Reaming the medullary canal 7
Rasping the medullary canal
7
Trial using rasp
7
Restrictor sizing and insertion
8
Insertion of definitive femoral implant
8
Modular head insertion
8
Sizing guide
9
Ordering information
2|
10
TaperFit™
Design I History I Function
Cemented total hip replacement
|3
TaperFit™
Operative summary
4|
a. Femoral canal preparation
b. Tapered IM reaming
c. Rasping
d. Trial reduction
e. Restrictor sizing
f. Restrictor insertion
g. Stem implantation
h. Modular head insertion
Tap erfit Sy stem
Device part no(s):
E088.001
588.4501
Description:
Taperfit stem
MAGNIFICATION:
115%
(1.15:1)
Advanced Bearing
Device size:
45mm offset, Size 1
Trunnion type:
EuroCone
Trinity™
Acetabular Syst
em
Surgical technique
includes
TaperFit™
Pack No.
Sheet 2 of 9
cement
Cemented Total Hip Repla
Surgical technique
100
90
80
70
60
50
40
30
20
10
0
REV: 01
Template No: 288.913
ECR: 10645 DATE: 11 Nov 10
Pre-operative templating
Surgical exposure
Acetabular preparation
Pre-operative templating using the Corin X-ray
templates provided allow the surgeon to identify the
implant offset and sizes appropriate for the patient,
and also to plan the position in which the components
will be placed. Whilst templating, allowance must be
made for a complete cement mantle for the chosen
component.
Full exposure of both the acetabulum and proximal
femur are required to permit effective preparation and
implantation.
The acetabulum is prepared as instructed for the
chosen acetabular cup system. The TaperFit stem can
be used in combination with the Trinity acetabular cup
system or the Cenator cemented polyethylene cup –
please refer to the respective surgical technique (see
overleaf for Cenator).
Femoral neck resection
The osteotomy line for neck resection usually runs
from the superior surface of the base of the neck
to a point midway between the upper margin of the
lesser trochanter and the inferior aspect of the head.
However, since the TaperFit stem is a collarless device,
the level and orientation of neck resection is not critical
to this procedure.
|5
TaperFit™
Cenator cup acetabular preparation and implantation
Step 1. Reaming the acetabulum
Step 2. Insertion of the acetabular cup
The acetabular rim is identified and any osteophytes
and capsular remnants are removed.
Trial cups may be used to confirm the size selection
made at pre-operative templating.The acetabulum is
then prepared to accept bone cement which is applied
according to usual practice.
The acetabulum is reamed up to the appropriate
size, using sequentially larger reamers, until bleeding
sub-chondral bone is exposed and the acetabulum is
hemi-spherical.
In order to ensure an adequate cement mantle, the
final size of reamer used should be 4mm larger than
the cup to be implanted, e.g. to accept a 44mm cup
the acetabulum must be reamed to 48mm.
6|
If a flanged Cenator cup is to be used (which has a
0.75mm thick flange and is marked with concentric rings
2mm apart), then the flange should be trimmed to the
contours of the acetabular rim prior to cementing in place.
The chosen acetabular component is then mounted on
the acetabular cup holder by inserting the two prongs on
the holder into the two holes in the implant.
Note: If a cup with an EPW (extended posterior wall)
is chosen then the implant must be placed on the
introducer in the correct orientation: For a right hip,
the letter ‘R’ on the face of the implant should be
visible in the ‘R-window’ of the introducer. For a left hip,
the letter ‘L’ on the face of the implant should be visible
in the ‘L-window’ of the introducer
The cup can then be inserted into the bone cement. The
cup holder permits orientation of the cup as follows: with the
handle parallel to the long axis of the body, and the metal
shaft at 90° to the long axis, the cup will be placed at 45° of
abduction, in neutral so anteversion may then be applied by
appropriate rotation of the handle.
Pressure is applied to the back of the cup holder with the
pusher and excess bone cement removed.
The cup introducer is removed by squeezing the ‘trigger’.
The plastic-headed cup pusher is inserted into the cup and
firm pressure is maintained until the bone cement has fully
polymerised.
TaperFit femoral preparation
Step 1. Opening the femur
Step 3. Rasping the medullary canal
Step 4. Trial using rasp
The proximal femur is opened using the box
osteotome ensuring that this is positioned laterally
into the greater trochanter and with the appropriate
anteversion.
The medullary canal is then rasped sequentially
starting with the smallest rasp of appropriate offset
until the rasp equivalent to the prosthesis chosen at
templating is seated within the femur.
Stability and fit are assessed and, if satisfactory, the
rasp handle is removed. A trial neck is placed on the
spigot, a standard trial modular head of appropriate
diameter placed on the trial neck and a trial reduction
carried out.
Step 2. Reaming the medullary canal
The medullary canal is identified and opened using the
tapered reamer.
The rasp handle may be impacted directly using a
mallet, or the slap hammer may be used to both
impact and loosen the rasp.
Long or short trial heads may be used if adjustment is
necessary.
The neck trials are suitable for use with all rasp offsets.
A pin may be placed through the holes in the rasp to
increase leg length and to maintain the rasp position
within the femur whilst performing a trial reduction.
|7
TaperFit™
Step 5. Restrictor sizing and insertion
Step 6. Insertion of definitive femoral implant
Step 7. Modular head insertion
The rasp is removed using the rasp handle and slap
hammer. The correct size of cement restrictor is
determined by using the four double-ended Corin
restrictor sizer instruments. Aim for a firm fit so
that third generation cementing techniques can be
used effectively if required. Place the chosen size of
restrictor onto the end of the introducer and push
down into the femoral canal to a depth of 20mm distal
to planned final stem tip position.
The definitive implant is mounted onto the stem
introducer and the stem centraliser placed on the distal
tip. The stem is then pushed firmly into the bone cement
until it reaches the level at which the rasp sat during the
trial reduction (this may be checked by reference to the
three marks on the implant).
A further trial reduction may be carried out, using a trial
head or a definitive modular head (matching the trial
head used) is then securely placed onto the trunnion.
The wound is then closed according to the surgeon’s
usual practice.
Note: Ideally the canal should be thoroughly
cleaned and dried using pulse lavage and
tamponade prior to retrograde cement injection
with a cement gun and proximal cement
pressurisation.
8|
Pressure is applied, excess bone cement is removed,
and the stem introducer detached from the stem when
the cement has fully polymerised.
Sizing guide
offset
stem length
neck length
stem size
offset (mm)
CDH stem neck length (mm)
stem length (mm)
CDH
36.0
35.9
127.0
38mm
offset
stems
stem size
offset (mm)
neck length (mm)
stem length (mm)
0
38.0
39.0
149.0
1
38.0
39.0
149.0
2
38.0
39.0
149.0
3
38.0
39.0
149.0
4
38.0
39.0
149.0
45mm
offset
stems
offset (mm)
neck length (mm)
stem length (mm)
45.0
40.5
149.0
45.0
40.5
149.0
45.0
40.5
149.0
45.0
40.5
149.0
45.0
40.5
149.0
50mm
offset
stems
offset (mm)
neck length (mm)
stem length (mm)
50.0
42.3
149.0
50.0
42.3
149.0
50.0
42.3
149.0
50.0
42.3
149.0
50.0
42.3
149.0
major diameter
restrictor size
minor diameter (mm)
cement
major diameter (mm)
restrictors
core diameter (mm)
IM size recommendations (mm)
1
2
3
4
10.0
14.0
18.0
22.0
14.0
18.0
22.0
26.0
4.0
7.0
11.0
15.0
8 ≥ Ø < 12 12 ≥ Ø < 16 16 ≥ Ø < 20 20 ≥ Ø < 24
core diameter
minor diameter
|9
TaperFit™
Ordering information
TaperFit femoral stems
Cenator cemented polyethylene acetabular cups
Eurocone (12/14) options
Standard cups with EPW
588.3600
588.3800
588.3801
588.3802
588.3803
588.3804
588.4500
588.4501
588.4502
588.4503
588.4504
588.5000
588.5001
588.5002
588.5003
588.5004
36mm
38mm
38mm
38mm
38mm
38mm
45mm
45mm
45mm
45mm
45mm
50mm
50mm
50mm
50mm
50mm
Offset
Offset
Offset
Offset
Offset
Offset
Offset
Offset
Offset
Offset
Offset
Offset
Offset
Offset
Offset
Offset
CDH
size 0
size 1
size 2
size 3
size 4
size 0
size 1
size 2
size 3
size 4
size 0
size 1
size 2
size 3
size 4
Centralisers and impaction grafting
188.555
181.901
181.902
181.903
TaperFit PMMA centraliser (pack of 5)
Impaction grafting canal occluder size 1
Impaction grafting canal occluder size 2
Impaction grafting canal occluder size 3
Complementary products
174.600
279.000
Hardinge femoral canal occluder, box 10
Canal occluder introducer
TaperFit X-ray templates
288.911100%
288.912110%
288.913115%
288.914120%
10 |
175.140
175.144
175.148
175.152
175.344
175.348
40mm
44mm
48mm
52mm
44mm
48mm
OD
OD
OD
OD
OD
OD
22mm
22mm
22mm
22mm
28mm
28mm
ID
ID
ID
ID
ID
ID
40mm
44mm
48mm
52mm
40mm
44mm
48mm
52mm
44mm
48mm
52mm
OD
OD
OD
OD
OD
OD
OD
OD
OD
OD
OD
22mm
22mm
22mm
22mm
26mm
26mm
26mm
26mm
28mm
28mm
28mm
ID
ID
ID
ID
ID
ID
ID
ID
ID
ID
ID
OD
OD
OD
OD
OD
OD
OD
22mm ID
22mm ID
22mm ID
22mm ID
28mm ID
28mm ID
28 mm ID
Flanged cups with EPW
175.640
175.644
175.648
175.652
175.740
175.744
175.748
175.752
175.844
175.848
175.852
Standard cups without EPW
176.140
176.144
176.148
176.152
176.344
176.348
176.352
40mm
44mm
48mm
52mm
44mm
48mm
52mm
Flanged cups without EPW
176.640
176.644
176.648
176.652
176.740
176.744
176.748
176.752
176.844
176.848
176.852
40mm
44mm
48mm
52mm
40mm
44mm
48mm
52mm
44mm
48mm
52mm
OD
OD
OD
OD
OD
OD
OD
OD
OD
OD
OD
22mm
22mm
22mm
22mm
26mm
26mm
26mm
26mm
28mm
28mm
28mm
ID
ID
ID
ID
ID
ID
ID
ID
ID
ID
ID
Cement restrictors
588.0001
588.0002
588.0003
588.0004
279.000
Cement restrictor size 1
Cement restrictor size 2
Cement restrictor size 3
Cement restrictor size 4
Canal occluder introducer
Modular heads for use with Cenator cup
BIOLOX® delta ceramic modular heads Eurocone (12/14)
CoCr modular heads Eurocone (12/14) options
E100.022
E100.122
E100.222
E100.026
E100.126
E100.226
E100.028
E100.128
E100.228
22mm
22mm
22mm
26mm
26mm
26mm
28mm
28mm
28mm
short
medium
long
short
medium
long
short
medium
long
Modular heads for use with the Trinity acetabular cup
CoCr modular heads Eurocone (12/14)
E321.028Small -3.5mm
E321.032Small -4.0mm
E321.036Small -4.0mm
E321.040Small -4.0mm
E321.128 Medium-0.0mm
E321.132 Medium-0.0mm
E321.136 Medium-0.0mm
E321.140 Medium-0.0mm
E321.228Long +3.5mm
E321.232Long +4.0mm
E321.236Long +4.0mm
E321.240Long +4.0mm
E321.332
Extra long +7.0mm
E321.336
Extra long +8.0mm
E321.240
Extra long +8.0mm
28mm
32mm
36mm
40mm
28mm
32mm
36mm
40mm
28mm
32mm
36mm
40mm
32mm
36mm
40mm
104.2800Small -3.5mm
104.3200Small -4.0mm
104.3600Small -4.0mm
104.4000Small -4.0mm
104.2805 Medium-0.0mm
104.3205 Medium-0.0mm
104.3605 Medium-0.0mm
104.4005 Medium-0.0mm
104.2810Long +3.5mm
104.3210Long +4.0mm
104.3610Long +4.0mm
104.4010Long +4.0mm
104.3215
Extra long +7.0mm
104.3615
Extra long +8.0mm
104.4015
Extra long +8.0mm
28mm
32mm
36mm
40mm
28mm
32mm
36mm
40mm
28mm
32mm
36mm
40mm
32mm
36mm
40mm
Instrumentation
588.9999.01
288.993
281.999
275.000
TaperFit instrument set
TaperFit impaction grafting instrument set
Standard impaction grafting instrument set
Cenator instrument set
| 11
References:
1. Fowler JL, Gie GA, Lee AJC, Ling RSM. Experiences with the Exeter total hip
replacement since 1970. Orthop Clin North Am 1988:19; 477-489.
2. Ramos JL, Pandit HG, Edwards S, Grover ML. Lateral approach to the hip
joint; does it predispose to malalignment of the femoral component in total hip
arthroplasty? British Orthopaedic Association, Annual Congress 1999, Glasgow,
Free Paper Session 16.
3. Malchau H, Herberts P. Prognosis of total hip replacement: Revision and rerevision rate in THR: A revision-risk study of 148,359 primary operations. Scientific
exhibition presented at the 65th Annual Meeting of the American Academy of
Orthopaedic Surgeons, March 1998, New Orleans.
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