2. What is Plaster of Paris?
Plaster – basic building material for coating
walls and ceilings.
Starts as a dry powder, harden when applied
together with water and heat.
Different type –
− Plaster of Paris (Gypsum)
− Lime plaster
− Cement plaster
3.
Different type use in different setting. As in
architecture, art, fire protection and even in
medicine.
Plaster of Paris is widely used in Medical
setting espescially in Orthopaedic department.
POP results from the calcination of gypsum or
calcium sulfate dihydrate (CaSO4, 2 H2O),
which partially dehydrates to produce a hemi-
hydrate (CaSO4 , ½ H2O).
4. History
- The term plaster of Paris was first used in the 17 th
century due to large quarry deposits of gypsum located
in Montmartre, a district of Paris. They mostly use them
for sculpturing, decoration and surface for painting.
- But researcher has found plaster wall and artifacts for
interior of Great Pyramids. This prove usage of plaster
has been since ancient times.
- Invention of plaster bandage can be attributed to Arabic
doctor in 1000 C.E. (Al-Tasrif). But POP bandages
were first used by Matthysen, a Dutch military surgeon
in 1952.
5. Indication of Plaster Usage
1) Chronically stiff joint.
2) Hard end feel contractions of any joint.
Secondary to:
- fracture, amputation, tendon rupture, lacerations or
repair, nerve repairs and burns
3) Deformity.
6. Plaster Type
1) Plaster of Paris (POP)
- Roll of muslin stiffened by dextrose or starch and
impregnated with hemihydrate calcium sulfate.
- It is cost-effective, non allergic and easy to mould.
- But it is heavy and fragile if contact with water.
2) Fibreglass
- Strong but lighter than Plaster of Paris.
- It is cool, water resistant and radiolucent.
- But it is more expensive.
7. Cast Application
- Clean skin and apply dressing if there is wounds. Apply
uniform thickness of cotton padding
- Soak plaster roll in water at room temperature
- Gently pick up the ends of the bandage with both hands
and lightly squeeze it, pushing the ends together
without twisting or wringing
8. - Hold relevant body part steady in correct position
- Apply the plaster by unrolling the bandage as it rests
on the limb. Overlap the previous layer of plaster by
about half the width of the roll
- Mould the plaster evenly, rapidly and without
intervention. Rubs each layer firmly with the palm so
that the plaster forms a mass.
- Mould until firm and let it completely dry for 24 hours.
- Same methods goes with fibreglass type plaster.
- For removal, we can use plaster shears or electric saw.
9.
10. Types of Cast
1) Bivalved - Can be removed, secured with
Velcro
2) Drop out cast - part of the extremity can be
moved
3) Cylindrical cast - typical fracture cast
4) Weight bearing casts - to hold extremity in
position to assist in weight bearing
11. Short leg patella
tendon bearing cast
Typical Cast
Long arm cast
Minerva jacket
Cylinder cast Short arm thumb spica cast
Hip spica cast
12. Complications
Due to tight cast:
Due to improper
- Pain
application:
- Pressure sore
- Joint stiffness
- Compartment
- Blisters and sores
syndrome
- Breakage
- Peripheral nerve injury
Others:
Due to plaster allergy:
- Deep vein trombosis
- Allergic dermatitis
(DVT)
13. Advice to patients
- Do not get the cast wet. Use plastic bags to
cover the cast while bathing.
- Do not walk on the cast.
- Do not stick anything down to the splint to
scratch or itch. This may lead injury and
infection.
- Instruct patient to return if there is numbness,
tingling, increase pain and impaired sensation.
