2. CHEMICAL FORMULA :
2CaSO4¡½H2O + 3H2O ==> 2CaSO4¡2H2O + heat
Hemi hydrated calcium sulphate
(POP)
Hydrated calcium sulphate
(GYPSUM)
PLASTER OF PARIS
3. ORTHOPAEDIC USES OF POP :
⢠To support fractured bones
â˘To stabilize joints in ligamentous injury
â˘To immobilize joints and limbs after surgery.
â˘To correct deformity as in CTEV
4. USED IN 4 FORMS MAINLY :
⢠Slab
⢠Cast
⢠Spica
⢠Functional Cast Brace.
5. ďśSetting time : Time taken to change from powder form to
crystalline form.
ďśDrying time : Time taken to change from crystalline form to
anhydrous form.
ďś Average setting time : 3-9 minutes.
ďś Average drying time : 24-72 hours.
6. RULES OF
APPLICATION OF POP
â˘Correct size of the roll to be chosen
â˘A joint above and a joint below the
fracture/injury should be included.
â˘Plaster should not be too tight or too
loose.
â˘Moulding should be done with palm not
with fingers to avoid indentations.
7. PADDING :
â˘Padding should be from distal to proximal with 50%
overlap.
â˘Extra over elbows and heels.
â˘One should be generous over bony
prominences.
â˘Always pad between digits when splinting hands/ feet
or when doing buddy strapping.
â˘Not to be applied tightly- danger of ischemia !!
11. STOCKINET
â˘It protects skin and makes the bandge application to
look nifty.
â˘To be applied on the skin before the padding is done.
â˘Always cut the stockinet longer than the splint to be applied.
â˘Available in various width .
â˘Not to be used in
FRESH TRAUMA.
13. BASIC PLASTERING TECHNIQUE :
⢠Plastering is a form of craft.
⢠Itâs a skill not to be learned from books but by continuous
practice.
â˘A good manipulative reduction can be spoiled due to a clumsy
plaster application.
14. SLAB :
â˘Slab is a temporary splint made up of half by POP and half by
bandage roll.
â˘Used in initial stages of fracture treatment, during first aid and
to immobilize the limbs post operatively.
Steps in application of slab â
â˘Slab is measured into required length
â˘For upper extremities use 8-10 layers and for lower extremities
use 12-15 layers or upto 20 depending on size of the person
â˘Trimmed to the requirement of of the area of application
15. â˘Slab held carefully at both ends and immersed completely in
tepid water.
â˘Lift out and momentarily bunch up at an angle to expel excess
water.
â˘Consolidate the layers of the slab to remove excess of air as
retained air causes reduction of plaster strength.
â˘Slab is positioned and smoothened out with the hands so that
the slab fits closely to the contours of the limb.
â˘Wet bandage is applied to avoid tightening from shrinkage after
coming in contact with the slab.
17. Above elbow slab in elbow flexion :
Indications
â˘Fracture both bones forearm
â˘Supracondylar # humerus of extension type
â˘Unstable proximal radius or ulnar #
Above elbow slab in elbow extension :
Indications
â˘Olecranon #
â˘Supracondylar # humerus of flexion type.
18. ďą U SLAB OR COAPTATION SLAB :
Indications :
ďFor Proximal and shaft of humerus fractures.
ďApplied to the medial and lateral aspects of the arm, encircling
the elbow and overlapping the shoulder.
ďUtilizes dependency traction and hydrostatic pressure to effect
fracture reduction
19. ďąBelow knee slab
Indications:
â˘Ankle fractures and dislocations post reduction
â˘Tarsal and Meta tarsal fractures.
Position :
ďProximal end â upto tibial tuberosity.
ďDistal end â upto MTP joints of foot.
ďFoot in neutral position.
20. ďąAbove Knee Slab
Indications
⢠Proximal and mid shaft Tibial fractures.
â˘Supra condylar # of femur
ďProximal end â as high in the groin as possible
ďDistal End â to MTP joints of foot
ďKnee in 15 degrees flexion.
ďFoot in neutral position.
21. CAST :
â˘In this form of splinting POP roll completely encircles the limb.
â˘Casting is used as a definitive form of fracture management and
also to correct deformity.
Steps in application of cast :
â˘After stockinet application and tidy uniform padding, appropriate
width of POP roll is selected. (generally 4 inch or 6 inch)
â˘Dip the roll in tepid water completely.
â˘Secure the end of bandage to prevent it from getting lost.
â˘Hold the bandage lightly with the other hand without compression.
22. â˘Immerse at an angle of 45o
â˘Keep under the water until bubbles start rising.
â˘Remove the excess water by compressing in axial direction.
25. Final Manipulation Is Done And The Reduction Held, With
Appropriate Molding, Until The Plaster Hardens.
26. During the evaporation period, the casted limb should
remain exposed and not fully covered by blankets.
27. TRIPLE SEQUENCE IN PLASTER APPLICATION :
Phase 1 : Examination And Rehearsal
Phase 2 : Plastering
Phase 3 : Reduction And Holding
28. Phase 1 : Examination And Rehearsal
â˘Examination of the displacement and assessment of the forces
required to reduce and hold the reduction.
⢠Need to assess effect of gravity on the displacement.
⢠Range of excursion from the position of greatest deformity to
the position of apparent reduction.
29. Phase 2 : Plastering
⢠Limb held by assistant in position of approximate reduction.
⢠Surgeon himself should apply the bandage.
â˘Quick application is more important than holding precise
reduction.
â˘Plaster should still be completely soft after completion to allow
final touches
30. Phase 3 : Reduction And Holding
â˘After applying sufficient plaster , surgeon prepares to apply the
rehearsed movement of reduction.
â˘Should be able to clearly recognize sensation of reduction.
â˘After applying rehearsed reduction, surgeon holds on, without
further movement to allow the cast to set.
â˘In the last few minutes, he should obliterate any abrupt
impression that might invite pressure sores.
â˘NOT TO FORGET CHECK XRAY should be done after
application of each cast to confirm the acceptability of reduction.
31. SPICA :
A cast of layers overlapping in a V pattern, covering two body
parts of greatly different in size, as the hip and waist, thumb
and wrist, etc.
Eg : Hip spica cast
Thumb spica cast
32. ďś Advantages Of POP :
â˘Cost effective
â˘Non allergic
â˘Easily moulded to different forms.
ďś Disadvantages of POP :
â˘Radio-opaque , may occlude # lines
â˘Heavy
â˘Easily breaks when comes in contact with water.
33. AFTER CARE OF POP :
⢠Keep the plaster cast dry.
⢠Mobilize all the joints which are not incorporated in the plaster to
their full range of motion once it becomes dry.
⢠Come immediately if any of the following symptoms develop
ďźExcessive pain
ďźExcessive swelling
ďźBluish or white discoloration of fingers or toes
â˘Notice any cracks in the plaster.
â˘Graduated weight bearing for lower limb #
â˘Physiotherapy of muscles within the plaster and joints outside
the plaster is necessary to ensure early rehabilation.
34. 3. COMPLICATIONS OF POP
ďśDue to tight cast
â˘Pain
â˘Pressure sores â
ďźThe patientâs complaints of a painful cast should never be ignored,
and the cast should be changed promptly.
ďźOften, this may reveal an area of early skin pressure or irritation
that could progress to full-thickness skin loss.
ďźCompartment syndrome and the resulting sequelae Volkmann's
Ischaemic contracture.
⢠Peripheral nerve injuries
35. ďś Due to improper applications :
⢠Joint stiffness and malposition of limb.
⢠Plaster blisters and sores.
ďś Due to plaster allergy :
⢠Allergic contact dermatitis â
ďź The skin symptoms of irritation were all mild and temporary.
ďźQuaternary ammonium compound BENZALKONIUM CHLORIDE
is the allergen responsible for
plaster of Paris-induced allergic
contact dermatitis
36. ďś Disuse Atrophy and Muscle Weakness â
â˘Muscles that do not function when under cover of plaster will
atrophy
â˘Not only can this result in cast loosening, but there may also be
functional loss.
⢠Motion and isometric exercises should be encouraged.
â˘Prolonged nonâweight-bearing treatment in a cast can also
result in disuse osteopenia, which can complicate recovery.
â˘Typically, radiographic features include loss of trabecular
pattern, a speckled or mottled appearance of the periarticular
surface, and a generalized âWASHED-OUTâ appearance
37. ďźWhen a limb is put into POP and the joints immobilized for a
long period joint stiffness, muscle wasting and osteoporosis are
unavoidable.
ďźThis can be reduced to a minimum by the early use of
functional braces, isometric exercise and early weight-bearing.
These in turn promote a rapid retrieval of function.
38. ďś FRACTURE DISEASE :
â˘A constellation of symptoms and physical changes has been
called âfracture disease.â
⢠Prolonged immobilization, especially in a nonfunctional cast, can
lead to a vicious cycle of pain, swelling, and unresolved edema.
â˘Edema fluid is a proteinaceous exudate that will congeal and
gets converted to a gelatinous material and deposited as a scar
tissue around joints and tendons causing joint stiffness,
contracture and tendon adhesions.
⢠Muscle atrophy, brawny skin /induration, and osteoporosis
follow
â˘Reflex sympathetic dystrophy may sometimes occur and
further complicate the picture
39. ďśCAST SYNDROME :
â˘Cast syndrome is a rare complication that is seen related to hip spica cast
â˘The syndrome occurs due to arteriomesenteric duodenal obstruction, and it is a
result of excessive abdomen and chest coverage.
⢠Symptoms are severe, and if left untreated, can be potentially lethal.
â˘Compression of the third part of the duodenum between the lumbar spine
and the aorta posteriorly and the mesentry and vessels anteriorly.
⢠This syndrome is precipitated by recumbency and increased lumbar lordosis.
â˘Avoiding constrictive body casts that increase lumbar lordosis prevents cast
syndrome.
⢠Nausea, epigastric fullness, and regurgitation should be carefully evaluated.
40. ď§ FIBRE GLASS CAST :
â˘A fiberglass cast is a lighter, synthetic alternative to the more
traditional plaster version.
â˘It is created by padding the extremity with cotton or waterproof
padding material, followed by wrapping several layers of knitted
fiberglass bandages impregnated with a water-soluble, quick-
setting resin
41. Advantages :
â˘Short setting time
â˘Immediate weight bearing
â˘Strong but weighs light
⢠Radiolucent
â˘Water resistance
â˘Wicks moisture better.
Disadvantages :
⢠High cost
⢠Canât be applied over wet wounds or immediately after trauma
⢠Difficult to remove
⢠Leaves sharp edges
⢠Less mouldable
42. PROPERTIES OF AN IDEAL CAST :
â˘Suitable for direct application
â˘Easy to mould or remould
â˘Nontoxic for patient
â˘Unaffected by water
â˘Transparent to x-rays
â˘Quick setting
⢠Able to transmits air, water, odour and pus
â˘Strong but light in weight
â˘Non-inflammable
â˘Non messy application and removal
â˘Long shelf life
â˘cheap