Procedures

Removal of plaster cast is a procedure that is done by qualified and experienced medical personnel. The procedure involves risk of injury to the patient and should be done with utmost care.

Equipment Needed for Cast Removal

Following equipment are necessary for removing a cast

• Scissors
• Benders
• Electric cutter
• Materials for washing limb
• Supportive bandages or appliances

The choice of apparatus for removal of plaster cast depends on several factors. Unpadded and skin-tight casts are cut with plaster shears. Completely padded casts can be cut with an electric plaster cutter.

General Points For Removal of Plaster Cast

The noise of the electric cutter frightens some children, and so shears may be used.

The procedure is explained to the patient, and the apparatus that you will be using should be demonstrated to make them feel at ease.

The cast should be cut steadily and smoothly. It is good to converse with the patient during the procedure of removal of plaster cast so that his attention is diverted.

The limb in plaster should be supported by sandbags. For lower limb casts, the patient lies on the side and for upper limb casts patient can sit or lie down. The patient is covered with linen and positions the patient’s limb appropriately. The position of the limb may be changed during the procedure as required.

Assure the patient that procedure is safe, the electric saw does not cut the skin as it vibrates. But do warn the patient about saw blade getting hot as it sometimes may cause discomfort.

A plastic skin protector strip may be inserted between the cast lining and patient’s limb in the area where cutting will occur. This would protect the skin further from blade injury.

Removal of Plaster Cast with Plaster Shears

The size of shears used depends on the size of the cast. Draw guidelines down the side of the cast making sure that the line does not run directly over any bony prominences.

The stockinette is snipped at the ends of the cast to allow the shears to be positioned above this lining materials. If stockinette has not been used, try to insert the blade between the plaster and the padding wool.

Insert the blade under the plaster, parallel to the skin with the handle held steadily in the vertical position. The other blade cuts through the cast from above, its handle should be parallel to the cutting line at rest. This is the starting position, and if the blades are incorrectly aligned, the lower blade will press into the flesh causing bruises or even lacerations.

After each cut, the blades should be realigned before the next cut is made. This prevents the skin wrinkling in front of the shears. These manoeuvers are important because the thick tips of the blades can press uncomfortably on the surface of the skin.

Remove the shears after every four or six cuts. Clear any clogging in the blades and use the plaster benders to open out the cast.

Never try to cut around corners. Always remove the blades and cut from the opposite end of the line to meet the end of the cut already made.

When using shears, keep the elbows relatively still and apply the cutting force from the shoulder girdle and chest muscles. This gives a more controlled power and saves energy.

Removal of Plaster Cast with Electric Cutter

The electric cutter must only be used to cut completely padded casts.

When using an electric cutter make sure that:

• No strain is put on the cable, and enough cable is available for the operation in hand.
• The cable does not come near the cutting blade.
• The operator’s hands are dry.
• The apparatus is serviced regularly.

Position the patient correctly, and mark the line of cutting. Reassure the patient by showing them that the cutting blade works by oscillation, and only cuts hard materials. The blade becomes hot when used and cutting must be stopped if the patient feels any scorching. Start cutting with reduced pressure after examining the area involved.

Position the blade at the start of the guideline, apply gentle pressure and move the cutter smoothly along the line. When cutting starts, there is a tendency to grip the cutter which exerts unwanted pressure on the cast. A new operator should be trained to reduce the pressure by continuous but gentle wrist movements.

The electric cutter should always be used carefully especially near bony prominences such as the medial border of the foot leading to the big toe.

Care of the Part After Cast Removal

The cast may have to be bivalved for inspection, X-ray purposes and sometimes for skin preparation prior to operation. In these circumstances, the halves are replaced and held by a bandage until further direction is given.

On removal of the parts of the cast, support the limb between sandbags and closely inspect if for any signs of trauma inflicted during the removal procedure.

Wash and dry the part.

Gentle massage with oil, or cream, may help to restore normal nutrition and elasticity to the skin. After an extended period of immobility, some edema is likely initially if the part is dependent. Elastocrepe or other supporting bandages may be needed.

These should support the whole area released from the cast. The new support should be applied at once and in the case of upper and lower limbs, the patient should be advised to resume normal activity gradually, and to rest the part at regular intervals while maintaining digital exercises when at rest.

When a plaster is removed before surgery, skin texture and nutrition should be improved by massage. This can help to stimulate good wound healing after elective surgery.

Patients should always be warned that they may be incapacitated without the cast for the first few days until the muscles have regained their tone.

Complications During Cast Removal

Injury to Skin

The most common problem occurring with cast removal is an injury to the skin. Plaster can be removed by using an electric cast cutter or a hand cast cutter or by soaking the cast in water and unwrapping it. The operator must be careful to avoid cutting the skin when using the electric cast saw

This kind of complication is more common in an uncooperative patient or a child.

Swelling of Limb after Cast Removal

Limb swelling after cast removal is a common problem. It has been named as fracture disease by some.

After removal of the plaster cast, the most com­mon problem is swelling of the limb. This has been called fracture disease by some.

The patient should be encouraged to conduct active exercises of fingers or toes and limb elevation.

After removal of the cast, an elastic bandage can be wrapped around the extremity, but the patient should be instructed to continue active exercises and elevation.

A certain amount of muscle weakness fol­lows the removal of plaster and doing active exercises to strengthen muscles may be required for a long time to regain strength.

Save

Save

A plaster cast is given for treatment of fractures and other orthopedic ailments. Though a very safe mode of treatment, complications of plaster may occur.

Main complications of plaster are stiff joints, muscle wasting, and impaired circulation. Physiotherapy and good nursing can help reduce these complications and speed the final recovery.

Complications of plaster cast can be divided in systemic, which affects whole body or local which affects limb where plaster has been applied.

Local cast complications can be further classified as immediate and delayed.

Systemic Complications of Plaster Cast

The most serious is deep venous thrombosis leading to pulmonary embolism. Pain in the calf is an important sign needing medical advice.

Immobilization in trunk plasters or plaster beds may also produce nausea, abdominal muscle cramps, retention of urine and abdominal distention.

Good nursing and diet with regular exercises will help ensure that the initial period of extensive immobilization is achieved without complications.

Local Complications

Allergy

A patient might be allergic to the material of cast, the preservatives and other substances in the cast. It is not that common. Allergies are more common with newer synthetic cast materials.

Skin Trauma

If the limb is allowed to move while the plaster is setting, a ridge forms in the plaster, creating a pres­sure point on the underlying skin.

Such a ridge commonly forms in the dorsum of the ankle, the popliteal fossa, and the cubital fossa.

Pressure points may be created by denting caused by the operator’s fin­gers  while the cast is being applied. Complaints of pain or burning must be taken seriously, and the cast must be windowed to inspect painful areas.

Rarely, very hot water used to wet the plaster rolls can cause the burn.

Swelling

A plaster produces constricting effect on the limb and most of it is well tolerated but a moderate constriction will produce compression of the veins, damming the blood, and causing swelling, discomfort or pain, and a blue color in the skin and under the nails.

Swelling is a natural sequel to an acute injury that produces a fracture. If the extremity is placed in a cast too soon after injury, ischemic changes may result from neurovascular compromise.

A freshly fractured extremity may be splinted or placed in trac­tion until swelling subsides.

Casts should be trimmed back to the metatarsophalangeal joints of the foot and the metacarpophalangeal joints of the hand to provide for the inspection of the fingers and toes. This helps for early detection and to detect signs of neurovascular compromise in the extremities.

Temporary remedies such as elevation of the limb and exercising the digits may be tried, but, if persistent, the constriction must be relieved. The cast can be splint and eased or bivalved, taking care not to damage the skin.

Impaired Arterial Supply

A pale skin which is cool and without a palpable pulse indicates that the arterial supply is disrupted. After the pressure on the fingernail, the color does not immediately return. This is a serious complication. Medical advice must be sought immediately.

Splitting the cast may relieve the arterial compression but sometimes surgery may be necessary.

Incomplete arterial occlusion may present with pain or aching with loss of power. If in doubt ask for medical advice.

Pain

Pain has many causes. This may be due to tissue damage at injury or reduction, swelling within the cast, muscle spasm, pressure on blood vessels or nerves, skin irritation or sores. Although diagnosis may be difficult, persistent pain or intermittent acute pain should not be ignored. Medical advice must be sought.

Plaster Sores

The most common cause of sores is the pressure of the plaster on the skin due to poor cast application.

Cast wedging, which is used for correction of angular defor­mities  can cause skin pressure can occur at the level of the wedge.

The patient may report burning, itching or stabbing pain.

Children may have disturbed sleep and elevated temperature.

Signs that may suggest plaster sore

• Heat and swelling of the digits.
• Increased warmth over a localized area of the cast localized odor
• Visible pus or staining of the cast.

The most likely reasons for plaster sore development are:

• The poor technique with adequate padding, or a ridge inside the cast, or failure to trim the ends of the cast correctly.
• Local cast breakdown with skin irritation due to poor care
• Foreign bodies may easily slip between the cast and the skin. Children especially may insert small toys, coins or beads while hairgrips may fall inside the cast.
  Patients should be warned of these damages and also to care for the plaster edges since wetting will cause plaster crumbs to be detached and fall inside the cast.
• Scratching at minor irritation beneath the cast with metal implements or knitting needles may cause trauma and infection. Such irritation should be reported and investigated early.
• Plaster soakage leading to skin damage and infection
• Cut edges of plaster following splinting or bivalving or window procedures may irritate the skin especially if swelling occurs around the edge.

Development of plaster sore is very painful. It is a constant nagging pain that does not leave the patient. The patient is often able to pinpoint the sore area. If the patient complains of unrelenting pain or digging sensation the part should be examined.

It should not be ignored at any cost otherwise the results could be disastrous consequences.

A window is cut in the plaster, with an electric cutter. Then underlying padding and lining is removed to inspect the skin.
The skin is examined for any redness or wound.

Grades of Sore

Sores are graded according to the depth of the involvement.

• Grade I-Redness of skin

• Grade II-Involvement of Subcutaneous Tissue or cellulitis

• Grade III- Involvement of Muscles

• Grade IV- Bone Deep

The treatment of sore depends upon the grade. While grade I only require removal of offending pressure others require treatment that varies from simple dressings to surgical debridement and reconstructive procedures.

The fracture needs to be splinted throughout. In some cases, it might be pertinent to shift to external fixation of the fracture.

Apart from immediate complications and plaster sores, there are many other problems that can arise with plaster application.

Loss of Reduction

Because swelling occurs with most fractures especially after reduction, the technician puts padding under the cast to protect the skin. This padding gets compressed. After 48 hours when the edema is subsiding, the cast may be too loose to hold the bone ends in position against undesirable muscle action.

Such displacement may be sudden and cause pain or gradual being first noticed on the next x-ray. This complication may seriously delay sound healing and may produce permanent deformity.

Medical advice must be sought if the position is suspect.

If the limb is not properly held during the casting procedure, it could also be responsible for malpositioning.

Nerve Damage

Loss of power, tingling, and numbness distal to the cast are signs of impaired nerve function. The cause may be direct compression by bone ends or plaster pressure, indirect compression of oedematous tissue or tourniquet effect, or reduced blood flow.

Routine testing of power and sensation will detect any defect quickly. Corrective action includes relieving cast pressure, supporting and protecting paralyzed parts, and physiotherapy to help restore normal function of muscle and joints.

Breaking of the Cast

Breaking and softening of the cast occur due to many reasons

• Cast gets wet [in case of POP casts. This is one of the complications of plaster of Paris cast, newer materials are water impervious]
• Persistent pressure on a particular area such as the foot or heel
• The patient fails to take proper care of the cast [for example in children, noncompliant patients or elderly patients]
• Fall on the casted extremity
• Self-repair attempts by patients

In case the break is noticed in the cast, the patient must contact the physician for repair or replacement of the cast.

Complications of Special Plaster Casts

Body Casts

Body casts are not used as frequently now as they were used before. The most frequent complication of the cast is that it fails to fit the body and keeps on sliding down.

Due to this movement, pressure necrosis over the sacrum and under the axillae is a common complication.

Gastrointestinal discomfort is manifested by a fleeting sensation of gastrointestinal fullness or per­sistent discomfort known as “cast syndrome which involves compression of mesentric artery.

Minerva cast is a body cast with an extension that incorporates the cervical spine, and it is used in the treatment of lesions of the cervical spine.

Again, the cast is not used as frequently as before due to better surgical care and custom orthoses.

Pressure areas occur over the sacrum, coc­cyx, and iliac crests and around the axillae.

Paresthesia in the area of the axillae may occur.

Loss of alignment occurs over the fracture site when the cast slips down or when the patient at­tempts rotational movements of the neck.

Shoulder spica cast is essentially a body cast with the inclusion of an upper extremity.

Hanging Cast

Hanging cast is used to treat fractures of the humerus.

If the cast is very heavy, a distraction of fragments may occur.

The hanging cast is ineffective if the patient is allowed to lie flat in bed. The patient must be instructed to maintain a sitting position while sleeping.

in an obese patient, a hanging cast may cause skin problems changes can occur in the axilla.

Arm Casts

Long arm cast extends from the base of the metacarpals almost to the axilla. Pressure areas can occur at the base of the thumb or in the cubital fossa. Cubital fossa pressure may occur when the POP cast is applied in two parts.

Other problems associated with this cast are flexion contractures of elbow and hand. Exercises after cast removal would help to overcome this problem.

Sometimes the patient put some objects under the cast, mostly to relieve the itch. Patients must be forewarned about this and instructed not to do this.

Short arm cast extends from the elbow to heads of metacarpals and is prone to slide if the wrist is in the neutral position.

Hip Spica Cast

The hip spica cast is used in the treatment of in­juries of the femur, hip, and pelvis and includes opposite leg to a variable extent.

Sacrum, coc­cyx, trochanters,  popliteal and calf regions are prone to pressure changes.

The patient may be turned from side to side and from supine to prone to prevent pressure sores.

Hypercalcemia can develop in patients with Paget disease or metastatic disease during prolonged immobilization.

Leg Casts

These are long leg casts and short leg casts.

The long leg cast is used to treat many injuries by immobilizing in plaster the entire lower extremity from the ankle to the thigh.

Long leg cast is prone to breakage at the thigh and at the foot-ankle junction.

Pressure areas are common over the heel. Burning pain in the heel should be investigated; the heel of the cast should be windowed and the skin examined. If there is evi­dence of only minor irritation, the plaster patch should be replaced and sealed with adhesive tape or plaster. If the window is allowed to remain open, the area swells (ie, window edema), and pressure necro­sis occurs around the edges of the window

In a patient with a short leg cast, which extends from below the knee to ball toes, the cast can impinge on the thigh on flexion of the knee.

The cast wears and softens when the patient repeatedly rests the cast on the floor with the weight of the leg pressing on the heel.

Pressure changes may occur on the skin over the patella and head of the fibula.

Pressure on the head of the fibula, if persistent may result in peroneal nerve damage.

In conclusion, utmost care from applying person and the patient is required to avoid any complication of the plaster cast.

How to Avoid the Complications of Plaster Cast

Plaster cast complications can be reduced by taking all precautions of application of the cast, keep a vigilant eye and making sure that patient is well instructed about the care of cast.

• Application of the plaster cast should be done by a skilled person in the proper manner
• Patient, as a routine, should always be called for follow up examination next day.
• Strict elevation of the limb should be instructed.
• The patient should report on every pain that is not relieved, swelling, bluishness or pallor of the distal part.
• The patient should be carefully examined in the follow up for probable complications of plaster cast