This document provides information about hip disarticulation prostheses. It begins by defining hip disarticulation as the surgical removal of the entire lower limb through the hip joint. It then discusses some key challenges with hip disarticulation including reduced mobility and increased energy expenditure during walking. The document outlines the main causes of hip disarticulation amputation and notes that only 20% of patients use a prosthetic leg full time. It provides an overview of the evolution of hip disarticulation prosthesis designs. The document details important considerations for prosthetic management of hip disarticulation including patient evaluation, casting techniques, socket design, components, alignment, and training.
2. INTRODUCTION
• Hip Disarticulation is the surgical removal of the entire lower limb by
transection through the hip joint
• Trying to overcome the loss of three weight – bearing joints, rather
than one or two.
• Not routinely seen in the average clinical practice.
• Reduce mobility and increased energy expenditure during gait.
• Prosthesis fitting is therefore limited to motivated and physiologically
vigorous individuals and even then a significant number don’t
become long term user.
3. CAUSES OF HIP DISARTICULATION AMPUTATION
Hip disarticulation (Hd) accounts for only 2% of lower extremity
amputation in the India and is mostly performed for; ( listed by
number of occurrence)
1. Malignant musculoskeletal tumors ( most often in younger patients)
2. Limb ischemia ( perivascular diseases and complications to diabetes)
3. Trauma ( such severe traumas often result in the death of the patient)
4. Severe lower limbs infections ( chronic skin or bone infection)
5. Medical negligence
4. PROSTHETIC POINT OF VIEW
Most Prosthetist have little experience with this type of amputation- only 20%
of hip amputees use a prosthetic leg full-time (i.e. 8 to 12 hr./day)
From these 20% only a small minority use a prosthetic leg without a cane or
crutch
This small minority of full time users without walking aids consists primarily of
the young patients with malignant tumors.
There is a persistent belief within the medical community that most middle aged
hip- disarticulation amputees will ambulate with crutches or a wheelchair only!!!
5. Level of amputation in hip disarticulation
Above the lesser trochanter True hip disarticulation hemipelvectomy
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7. EVOLUTION OF HD PROSTHESES
Tilting-table
Prosthesis (1940)
U.S. Navy Hydraulic
Prosthesis(1945)
Saucer-type
Prosthesis(1957)
Canadian Hip
Disarticulation
Prosthesis(1954)
8. UCLA Anatomical H.D.
Prosthesis(1980)
Dycor´s Roller Track
Prosthetic Hip (1991)
Ortho-system
butterfly socket
(1997)
Silicone frame socket
with Hipo-gross-Aqua
hip joint (2000)
EVOLUTION OF SOCKET TECHNOLOGY
9. Glenrose Semi-flexible
Hip Disarticulation
Socket (2005)
Bikini Hip Socket
technology (2013)
Advances flex Hip
Disarticulation Socket
Design (2001)
11. PATIENT EVALUATION
POINT MUST BE REMEMBERED :-
a. balance,
b. lower abdominal tissue condition,
c. pelvic lordosis.
a) BALANCE is needed to successfully put on and ambulate with the limb with minimal
assistive aids. If this is not present, the client may not be considered a good prosthetic
candidate.
b) ABDOMINAL CONDITION must be evaluated for volume reduction and shaping to
create a volumetrically tight and accurate anteroposterior (AP) fit between the sacrum
and lower abdomen. The presence of any redundant or fleshy tissue should be noted
because it must be contained and shaped to create reaction surfaces for proper
prosthetic function.
c) PELVIC LORDOSIS must also be evaluated because this is the main biomechanics
work source during gait for maintaining knee stability and initiating knee flexion. To be
successful in gait, the amputee should be able to demonstrate active pelvic lordosis
using the muscles of the lower back and abdomen. The most successful amputees are
able to maintain a low weight so that the maximum lordotic range of motion may be
captured.
12. MEASUREMENTS
• Tight mediolateral measurements are also necessary to preserve ML
stability during gait.
• ML measurements
Over the iliac crests
Between the trochanter and the iliac crests
14. CASTING TECHNIQUES
There are two main methods of taking impressions:-
1. forming blocks
2. total suspension casting
15. FORMING BLOCKS
STEPS INVOLVED :-
i. The iliac crests, costal margin, pubis, femoral head or joint, and ischium are
marked.
ii. Plaster is wrapped over the lower limb from the perineum to 2 inches proximal to
the iliac crests, and reinforcing splints are added to the ischial area.
iii. The iliac crests are modified using plaster rope, surgical tubing, or radiator hose to
forcefully compress the tissue circumferentially and downward.
iv. In one method, the plaster rope is squeezed by being twisted around a dowel or
hammer handle to attain good loading. The rope should be flattened in the sacral
area to avoid localized pressure over the spinous processes.
v. The patient is then seated on a flat surface and 45° forming blocks are placed
anteriorly and posteriorly to create the AP reaction surfaces necessary for
ambulation.
vi. The posterior block is placed to load the gluteus and provide some relief for the
ischium.
vii. The anterior block is placed to help form the geometry for the hip attachment plate
with 5° of external rotation.
viii. The posterior forming block provides the counter pressure needed to maintain
contact with the anterior block (Figure3).
ix. Forming blocks work well for thinner clients with good muscle tone.
x. For those who have soft abdominal tissue, the blocks may tend to distort the mold
by expanding the ML.
16. Total Suspension Casting
STEPS INVLVED
i. The casting garment is suspended from the
ceiling using a mechanical winch device.
ii. When the support height has been adjusted
to the point where the iliac crests are even,
the same landmarks are indicated and the
plaster splints are added.
iii. The iliac crests are modified with the same
roping technique, and the ischium is cupped in
the palm of the hand (Figure 4).
iv. The disadvantage of this technique is that the
anterior surface is not clearly defined.
v. Some Prosthetists use both casting methods
by containing the tissue in suspension and
then using forming blocks to place the hip
joint.
17. AFTER CAST ( PREPRATIONS BEFORE MOLD)
• Often the initial cast that is taken does not reduce the
volume adequately to create a tight interface.
• For this reason, the client should recline in the cast
and the anterior panel should be cut.
• The anterior section is squeezed together, lapping the
anterior panels.
• The location is marked and the cast is removed.
• Before the mold is filled, the cast is again squeezed to
this point and secured to eliminate extra interface
volume and maintain circumferential tension.
18. MODIFICATION
• After the cast is removed, the landmarks are remarked.
• Plaster is removed from the anterior portion of the mold, avoiding the
pubis.
• When the abdomen is more pendulous, flattening is adequate;
• thinner individuals may have a slight concavity to load the abdomen.
• The posterior sacral area is also flattened along the lower back to
maintain tight AP pressure.
• To ensure a tight fit, one half inch of material should be removed
between the trochanter and iliac crest to avoid the anterior superior iliac
spine (ASIS) and the iliac crests from the measured ML.
• The superior iliac crest modifications made with the plaster rope are then
deepened by one quarter to one half inch even to the crests.
• Some loading of the gluteus is also advisable to avoid too much ischial
pressure.
• SOME PROSTHETISTS have suggested that medial ischial pressure is
advantageous but achieves little biomechanically without a distal reaction
point.
• Cupping of the ischium seems to be the most comfortable geometry.
• Relief may have to be added to the pubis, iliac crests, and ASIS.
19. SOCKET DESIGN
• The socket may be made with a side-opening or anterior- opening configuration, although the latter
predominates because it is easier to put on and remove.
• The trimlines are approximately 2 inches proximal to the iliac crests and through the perineum. A small
suspension band is cut to provide relief on the contralateral ASIS.
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30. COMPONENTS OF HIP –
DISARTICULATION PROSTHESES
1) PROSTHETIC HIP JOINTS
2) PROSTHETIC KNEE JOINTS
3) PYLON
4) TUBE CLAMP ADAPTER
5) PROSTHETIC FEET
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42. PYLON
• Different pylons and attachment components are also available.
• Twenty-two-mm Paediatric sizes are available along with the more common 30-mm pylon, and 34-mm pylons are available
for heavier loads.
• It is important to include an angled tube clamp above the knee to receive the upper femoral pylon, because this usually
has a considerable anterior angle.
• Carbon composite strut systems have been introduced that offer more dynamic motion and shock attenuation during
stance.
• The strut flexes when loaded and releases its force at the beginning of swing to increase hip and knee angular
acceleration, which can help speed the step.
• The disadvantage of this system is that the spring is lessened as the strut is shortened, and too soft a spring may dampen
the initial anterior Lordotic movement.
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48. MEDIO-LATERAL STABILITY
To reduce undesirable perineal pressure, the canadian
type socket is contoured to avoid excessive
mediolateral motion.
Throughout the stance phase of the prosthesis, the
body’s center of gravity “W” exerts it’s downward
force medial to the vertical support point “I”.
The short distance between the line of gravity and the
vertical support point minimizes the displacement.
Sliding is reduced further by the diagonal forces
exerted by the waistband over the sound hip as “H”
and by the socket “S”.
49. Anterio-posterior stability
At initial contact, as the prosthetic heel touches the
ground, the GRF passes posterior to the ankle axis, the
heel cushion compresses and the foot is lowered to the
ground.
At the same time an extension moment is created at the
prosthetic knee as the GRF passes anterior to the
prosthetic knee joint axis.
By midstance, alignment stability is maximal as the
GRF now passes posterior to the prosthetic hip joint
axis and anterior to the prosthetic knee joint axis.
As forward progression continues into pre-swing, the
GRF moves posterior to the prosthetic knee axis,
allowing the knee passively bend to facilitate swing
phase foot clearance, while weight is being shifted
onto the opposite limb.
50. ALIGNMENT
• Stability of the hip disarticulation prosthesis relies primarily on the alignment of the prosthesis.
IN THE BENCH ALIGNMENT :- A line is projected from the hip centre through the knee centre.
• This line should fall 25 to 50 mm behind the heel of the shoe.
• In the frontal plane, the hip joint should be placed 10 mm lateral to the frontal one-quarter mark with 5° to 10° of
external rotation to match anatomic lower limb rotation.
• The hip joint placement is established sagittally with the forming blocks.
• The knee center and midfoot are placed in relationship to a plum line from the bisection of the interface based on
their design.
• For example, a single-axis knee is placed 15 mm posterior and a dynamic response midfoot is placed 20 mm anterior
to the bisection.
• The length of the prosthesis is 12 mm shorter than the sound side, so that the foot can clear the floor during
midswing.
• DURING DYNAMIC ALIGNMENT :- The hip joint should be adjusted so that it is not engaged before midstance
during forward pelvic lordosis.
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52. CHECKOUTS
• The Prosthesis should be 1cm smaller in length than the normal leg
• The line joining the HIP joint and BACK of the heel should paas 1cm anterior to the knee
joint in full extension
• Socket should provide Firm and Comfortable Support to ISCHIUM and in AP and ML
directions in standing position.
• The prosthesis should not drop away more than 2 cms. When amputee is asked to lift it
from the floor.
• In sitting a chair the pelvis should be level there should not be any discomfort or
restriction.
• In sitting the prosthetic thigh should not appear abnormally longer than the normal
thigh.in sitting the sheen piece should be vertical.
• After the walking is commenced knee stability after heel strike should be observed the
heel of the foot should be soft otherwise it would be soft otherwise it would cause knee
BUCKLING
53. TRAINING
1. STANDING AND WEIGHT TRANSFER FROM ONE FOOT TO ANOTHER
2. THE TRUNK SHOULD BE STRAIGHT THROUGH OUT THE GAIT.
3. TRUNK SHOULD NOT LEAN FORWARD WHILE WALKING.