PLASTER OF PARIS

Question 1

WHAT IS PLASTER OF PARIS MADE UP OF?

Answer 1

 Hydrated calcium sulphate (gypsum)
 Plaster of Paris (Gypsum salt) is CaSO4. ½H2O in dry form, which becomes CaSO4.2H2O on wetting
 This conversion is an irreversible exothermic reaction.
 Plaster sets in a given shape on drying and setting time varies with its quality, and temperature of water

Question 2

IN WHAT FORMS CAN PLASTER OF PARIS BE APPLIED?

Answer 2

It can be applied in two forms i.e., 1. Slab or 2. a cast

Question 3

WHAT ARE THE INDICATIONS FOR POP?

Answer 3

) Indications for POP
1. Fractures
2. Dislocations
3. Correction of limb deformity e.g. congenital malformation
4. Prevention of pathological #s in osteomyelitis

Question 4

WHAT ARE THE EARLY COMPLICATIONS OF POP?

Answer 4

I. Early
1. Compartment syndrome-Impairment of circulation (tight cast)
2. Burns
3. Allergy to POP

Question 5

WHAT ARE THE LATE COMPLICATIONS OF POP?

Answer 5

II. Late
1. Muscle disuse atrophy
2. Joint stiffness (Ankylosing)
3. Nerve compression
4. Mal-union
5. Volkmann‘s contracture
6. Loose cast- Once swelling has subsided, cast may no longer hold fracture securely.
7. Plaster sores: caused by inadequate padding, irregularity of inner surface of cast, or FBs in the plaster.
8. Skin abrasion or laceration- complication of removing plasters, especially if an electric saw is used

Question 6

OUTLINE THE TECHNIQUE FOR APPLYING A POP

Answer 6

 Reduce the fracture, then thread stockinette over the limb and the bony points are protected with wool.
 Adequate anaesthesia and careful study of the x-ray films are both indispensable.
 Immerse POP in warm H2O and Plaster is next applied smoothly, taking a tuck with each turn, and smoothing each layer firmly onto the one beneath.
 While still wet the cast is moulded away from the bony points.
 With a recent injury the plaster is then split