Lecture 5
Trans-Femoral Cast Rectification
Preparing the Negative cast
Trim the cast
• Anterior
- Height from IT level = 5cm
• Medial
- Parallel to LOP(Lines of Position)
- 1.5 cm flare
• Posterior
- Perpendicular to LOP
• - Posterior shelf should be 3 cm fromthe wall
(From the medial wall 2.5 cm)
• Lateral
- Height from IT level = 5-7 cm
TF cast rectification Positive cast rectification
Medial wall
Anterior wall
Negative cast rectification
Lateral wall
Alignment of the cast
Posterior wall
- Frontal plan
Circumference
- Sagittal plane
Cast length Adductor and ramus relief
AP diameter Stump length
ML diameter Trim line
Top circumference
Overall shape
Cast Alignment
Lateral View
Posterior View
Check all the Measurements
Check all measurements of the cast. Write them down and compare them to the
measurements taken of thepatient.
Decide what will be the goal measurements, according to the guidelines.
Reduction Table Set up the Goal of cast reduction
Stump Cast Goal
Measurements Measurements Measurements
Circumference at
Ischial level
Circumference at
5 cm below
10 cm below
15 cm below
Cast diameter AP
Cast diameter ML
Stump length
Guidelines for Goal Measurements of the
cast
• Circumference at 5 cm below Ischial level should be less thanpatient’s
measurement. The reduction is generally 2 cm. However,
• Less is taken away if the top reduction is smaller.
• More is taken away if the top reduction is bigger thanaverage.
• Circumferences at all intervals below is 0.5 cm smaller thanthe patient’s
measurement
Guidelines for Goal Measurements
of the cast
• The reductions for circumferences below the Ischial level are less to leave space for the
tissues to accommodate when they arepulled down from the top and when they are
contracting.
• The amount of the reduction depends on the length of the stump,firmness of the stump
tissues and the size of the stump.
• Reductions will be less if the stump is long, firmand/or small.
• Reductions will be more if the stump is short, softand/or big.
Why more plaster is reduced at the proximal part of the cast but less
down to the distal?
• Purposes
• Provide suspension
• Compress the soft tissue and give a close fit
• Prevent rotation of the socket on stump
Length of the cast
• Measure the same way as patient’s stump.
• In general, the cast is longer than thepatient’s
measurement
• For a normal stump with good distal padding, the cast
should be the same lengthas the stump
• If the stump is bony with no distal tissue cover, then the
cast should be 1-2 cm longer than the patient’s
measurement
Medial Wall
• Flatten medial wall
-Transverse View
- Parallel to LOP
Medial view
-Flatten proximal 1/3 of the stump
Anterior view
- Vertical to the floor or parallel to frontal
plan alignment
- Medial shelf 2 cm
Anterior Wall
• Modify Scarpa’s triangle
* Blending smoothly fromthe
deepest point to the boundaries
* Recheck AP diameter
* The trim line is 5 cm higher than the
level of ischial seat
Lateral Wall
• Follow the proximal shape of pelvisregion of the
patient.
• Iliofemoral angle probably may help
• The top trim line is 2 – 4 cm higher than anterior trim
line.
• Check ML diameter
Posterior Wall
• Posterior shelf
- 2.5 cm from medial to lateral
- 3 cm from the posterior wall to the shelf
• Posterior lateral corner
-1.5 cm from the posterior wall to the shelf
• Check the angle between medial wall and
posterior wall (97- 100 degrees)
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Overall shape
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Check AP Diameter
• Measure from anterior to position of IT bone (1-
1.5 cm)
• This measurement MUST be 1.5 cm smaller
than the patient’s measurement, for patients
of normal size. It may be slightly less for very
small, or more for very large patients.
• This will ensure that the IT bone sitson the seat
and not inside the brim.
• If it is too big, remove from area under the
ischial seat.
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Adjust M-L diameter
• The ML diameter of the cast should be
measured as the sameway as you
measure during casting.
• If it is bigger than the patient’s measurement,
take plaster from the lateral wall with respect
of the greater trochanter.
Adjust the Flexion angle
The flexion angle of the cast is measured by placing one arm of
the protractor along the medial wall and the other on the long
axis (mid-line) of the cast, and subtracting this measurement
from 90.
The flexion angle refers to the flexion compared to the vertical.
The final flexion angle of the cast should follow what you have
decided during patient assessment.
(This will generally be about 5 flexion)
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Adjust the Flexion angle
• If the flexion angle of the cast is too small, add
plaster to the anterior aspect of the medial wall.
• If the flexion angle of the cast is too big,remove
plaster from this area.
• After that you can make room for ramus.Do not
add or remove plaster from the area near the
ischial seat.
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Adjust Adduction Angle
To measure the adductionangle,
– Place one arm of the protractor
along the ischialseat
– Place another arm along the
lateral wall of the cast
– Subtract this measurement from 90
Normally, it is about 5-7degrees
adduction
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Adjust the Adduction Angle
• To adjust the adduction angle, plaster
can be added to or removed from the
lateral aspect of posterior seat.
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Adjust the TF Cast length
Cast length is measured the
same way as the patient’s
stump.
• Normally, it is measured from
the ischial tuberosityto the
distal end of stump
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TF Cast Length
The goal for the cast length will vary
depending on the condition of the
distal end of the stump
Stump that has good distal padding,
the cast should be the same length as
the stump.
Make the cast 1-2 cm longer than
patient’s measurement for the stump
that does not have
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