Plaster of Paris is made from gypsum and was introduced for medical use by a military surgeon. It is used to create slabs and casts to immobilize and support limbs. A plaster cast is applied by wrapping the injured limb with cotton padding and layers of wet plaster gauze. It is important to monitor the limb for complications like swelling, discoloration or numbness after a cast is applied. Different types of casts are used for specific injuries or parts of the body. Newer materials like fibreglass sets faster and is stronger but lighter than traditional plaster.

1. PLASTER OF PARIS
PARENT COMPOUND:
GYPSUM : Sedimentary rock
Hemihydrated Calcium Sulphate WAS
USED BY THE SCULPTORS IN THE
PAST
Introduced for clinical practice by
ANTHONIUS MATHIJSEN -a military
surgeon.

2. PLASTER SLAB:
Slabs support the limb over a
particular surface eg: dorsal / volar
Made by making layers of the plaster from the
rolls. Adult lower limb : 20 layers Child
lower limb: 12-15layers
Adult upper limb : 15 layers
Child upper limb: 10-12 layers
In obese patients more number of layers may
be required

3. PLASTER CAST:
Encases the entire limb over the desired extent.
The thickness of the plaster determines the strength. The
required thickness varies according to the site (upper / lower limb)
and the age of the patient (child /adult) and weight of the patient.

4. NOMENCLATURE:
Depends on the extent of the plaster
slab / cast.
If the plaster extends from:
The toes - proximal to the knee : above
knee POP cast/slab
The toes – distal to the knee : below
knee POP cast/slab
The distal palmar crease – proximal to
elbow: above elbow POP
The distal palmar crease – distal to elbow:
below elbow POP

5. USES : SLAB /CAST
Immobilisation for soft tissue injuries :
ligament injuries
Immobilisation of bones and joints
Definitive treatment of fractures and
dislocation after reduction
Temporary immobilisation : first aid ,
post operative

6. USES…..
Immobilisation of inflamed joints
Support the limb : following nerve
injuries : Wrist drop etc.
Prevention and correction of
deformities
Making of an orthosis or prosthesis

7.
Stokinette applied : Sock like material : in excess of
the area
Bony prominences are padded well with cotton
layer/s
Cotton padding held in place with layer of guaze
bandage
Prepared slab / plaster roll dipped in water for ~one
minute
Rolls dipped one after other:after applying each
over desired area
After entire extent is covered, stokinette kept in
excess is folded over the edge of the plaster to give it
a smooth egde

8. AFTER APPLICATION OF
THE SLAB / PLASTER
1. The plastered area is always kept over soft
surface : pillows
2. Limb is kept elevated : decreases edema : post
traumatic/postural
3. Free joints (non plastered) joints : encouraged to be
mobilized
4. Patient should be under supervision for sensory and
vascular problems for at least one hour after
application.
5. In case of pruritis within the plastered area : no
attempt at introducing any object into the plaster
should be made.

9. PLASTER SETTING TIME
During application : 3-5 minutes :
MOLDING TIME
Molding time can be altered by
using hot /cold water
After application : 24- 48 hours :
DRYING TIME

10. INSTRUCTIONS TO BE
GIVEN TO THE PATIENT
Call the doctor immediately if one of the
following happens:
• Cast gets wet damaged or breaks
• Skin/nails of fingers/toes get discolored –
blue/gray
• Skin, fingers, or toes below the cast are numb,
tingling, or cold
• Swelling of the limb or toes
• Bleeding, drainage, or bad smell comes from the
cast and look for Severe or new pain within the cast

11. SPECIAL SLABS / CASTS:
Upper limb: U- slab/cast Cylinder
slab/cast ,Hanging cast
Lower limb PTB weight bearing cast
Body cast : To support / immobilise
the spine.

12. SPECIAL MATERIALS
FIBREGLASS
-Synthetic material
-Stronger
-Lighter
-More water- resistant
-Lesser setting and drying
time
- allows early weight bearing

14. Complications
1. Swelling : postural, tight plaster
2. Compromised circulation : Volkmann’s
ischaemia
3. Pressure sores
4. Pruritis within the cast
5. Fracture disease Prolonged immobilization:
Swelling,
Atrophy of the muscles
Joint stiffness

15. REMOVAL OF THE
PLASTER CAST
• REMOVED USING A PLASTER SAW
• A cast saw is a specialized saw made just
for taking off casts. It has a flat and rounded
metal blade that has teeth and vibrates back
and forth at a high rate of speed.
The cast saw is made to vibrate and cut
through the cast but not to cut the skin
underneath

18. HANGING ARM CAST