Introduction

Children require casts for a variety of reasons, including fracture management, post-operatively, or for pain management.  Types of casts used in paediatric patients include splints, backslabs, and full circumferential casts made from Plaster of Paris, fiberglass, or polyester.

Cast care can include cast assessment, removal, splitting, trimming, reinforcing, and wound reviews. The application of casts, such as splints, back slabs, and full circumferential casts, can be completed by nursing staff with appropriate training (see Appendix 1).

Aim

The aim is to provide nursing staff with guidance on the assessment and management of patients requiring cast care.

Assessment

Nursing assessment of both the patient and the cast is important to ensure early recognition of potential complications.  Cast assessment includes position, function, fit, and integrity. The assessment of the patient includes neurovascular observations (see RCH Nursing Guideline: Neurovascular observations).  

Any concerns about the cast or neurovascular status of the patient/limb should be escalated to the surgical team.

Cast Assessment

Casts should be well-fitted and appropriately shaped to support the affected area and prevent further injury. Nursing staff caring for patients with casts in situ should consider the following:

Position 

Fractures are positioned opposite to the mechanism of the injury when displaced or angulated. This will be assessed by the surgical team through x-ray or clinical examination. When assessing the position of the cast, consider:

• Is the limb/fracture in an appropriate position within the cast? Are joints placed in a position of comfort or immobilized? This will change depending on the fracture
• Does the position of the cast prevent joint stiffness or muscle atrophy? For example, is the wrist positioned in neutral or leg positioned in plantigrade

Function 

The function of the cast is to immbolise the affected area. This may include the joints above or below the fracture. When assessing the function of the cast, consider:

• Is the length of the cast appropriate? Casts that are too long or too short can cause pressure injuries, tendon or nerve pain and affect the alignment and union of the bone
• Are the unaffected joints able to move freely? For example, are the fingers/ knuckles exposed in a below elbow cast or can the patient bend at the knee in a below knee cast

Fit 

The fit of the cast should be firm but comfortable. When assessing the fit of the cast, consider:

• Is the affected limb in anatomical alignment within the cast? Does it follow the curvatures of the body?
• Do the distal and proximal ends of the cast fit appropriately? Casts that are too tight increase the risk of neurovascular compromise, compartment syndrome and pressure injuries. Casts that are too loose can cause friction from rubbing, malalignment or slow union

Integrity 

Broken casts can delay or prevent healing, create pressure injuries, promote skin irritation, maceration or infection.

• Skin irritation: Caused by known skin sensitivity, eczema or presence of rash (eczema creams can be applied prior to cast application)
• Maceration: Caused by wet or water damaged casts
• Infection: Signs of infection include ooze (visible through the cast), pain or strong odour. Infection should be investigated in post-operative patients, particularly those with K-wires. If infection is suspected, seek guidance from surgical team

When assessing the integrity of the cast, consider:

• Is the cast strong enough for its intended purpose? For example, is it durable for weight bearing
• Visually inspect the cast for cracking, fraying and wearing down

Potential Complications

Compartment Syndrome:

Compartment syndrome is an increase in pressure in a closed muscle compartment that causes muscle and nerve ischemia. Signs of compartment syndrome include:

• Pain unrelieved by analgesia
• Paraesthesia
• Pallor
• Paralysis
• Absence of pulse/s

Compartment syndrome is a surgical emergency and if suspected, the surgical team must be contacted immediately. The cast should be split or removed completely (including padding), and the limb elevated at the same level or higher than the heart to relieve pain and swelling.

Neurovascular observations are done regularly to assess:

• Pain
• Perfusion
• Sensation
• Motor function (movement)
• Swelling

For more information on compartment syndrome and how to complete neurovascular observations, see the Nursing guidelines: Neurovascular observations.

Pressure Injury

Pressure injury is damage to the skin or underlying tissue as a result of pressure. Pressure injuries from casts may be caused by:

• Poor application technique
• Finger indentations during molding
• Too much or not enough padding
• Rubbing/shearing from casts that are too loose
• If the patient is applying pressure e.g., resting their elbow or heel on hard surfaces for an extended period

For more information on prevention and management of pressure injuries, see the Nursing guidelines: Pressure injury prevention and management.

The risk of pain, swelling and pressure injuries can be minimised by:

• Elevation e.g., lower limbs can be elevated using pillows or bed mechanics and upper limbs can be elevated with either pillows, slings or box slings
• Frequent movement of the limb/joints e.g., wiggling fingers and toes
• Regular pressure area cares or repositioning of the patient

Materials used in cast application and management

Understanding the different materials used is important for effective cast assessment and management.

Materials used at RCH

Management

Removal

Cast removal can be completed by any clinician caring for a cast.

Equipment 

Depending on the material used, casts can be removed simply by unwrapping the bandage, cutting with scissors or using an oscillating saw. Removal equipment at RCH includes:

• Oscillating saw or ‘plaster cutter’: Used for circumferential cast removal as it is designed to vibrate and only cut through hard material, not soft material e.g., padding or skin. The saw heats up during use and if not used correctly, can cause friction burns
• Earmuffs/headphones: Worn for patient comfort and safety when using the oscillating saw
• Soft, thin plastic cutting strip: Placed under the cast as a barrier when using the oscillating saw, if there is concern for insufficient padding. Care must be taken if wounds or k-wires are present
• Spreaders: Used after the oscillating saw to spread the cast and crack it open
• Scissors: Heavy duty scissors with a blunt nose are used to cut through thick material with minimal effort. Can be used to remove most casts that are not circumferential

Preparing the patient

Prior to cast removal consider the following:

• Check the ‘order’ is correct, and the family has consented to the procedure. If unsure about the order, check with the treatment team (e.g., orthopaedics or plastics)
• Has the patient watched the RCH Be-Positive videos (RCH TV : Fracture Clinic) and knows what to expect?
• Utilise procedural pain management as required (Nursing guidelines : Procedure Management Guideline)
• If using the oscillating saw, advise the patient that the oscillating saw is noisy and designed to vibrate. It might to feel hot but should not touch the skin underneath
• Position the patient in an appropriate position so there is safe access to the limb. Ask for assistance if required to hold the limb for safety of the patient and staff member

Procedure

Backslab

• 1.Gather and prepare equipment (see equipment above)
• 2.Feel for hard cast material and soft material
• 3.Run heavy duty scissors along the soft material (be aware of the location of potential dressings or wounds)
• 4.Separate and remove cast

Circumferential cast

1. Gather and prepare equipment (see equipment above)

2. Offer earmuffs/headphones to the patient and staff member. Using the oscillating saw, begin cutting from either the distal or proximal end of the cast. The correct technique is to:

• Use the ‘straight in straight out’ method by pushing the oscillating saw to the edge of the hard cast material and then pulling it straight out. The blade should not be pushed past the cast material or dragged along the cast
• Avoid cutting in concave areas or over bony prominences (see bivalving information below)
• Avoid using a blunt blade. Use a new blade or rotate the blade (at least weekly)
• Regularly check the heat of the blade, particularly if the child complains of pain/burning sensation
• Be aware of wounds, k-wires and bony prominences. Take care cutting through areas where dry blood is present
• Always presume there is insufficient padding

3. Use cast spreaders to separate the cast

4. Run heavy duty scissors along the soft material (be aware of the location of potential dressings or wounds)

5. Separate and remove cast

Bivalving

Bivalving is when the cast is cut bilaterally for easy removal. This is common practice when removing any circumferential cast. The cast can also be bivalved and then secured with crepe bandage or soft cast to assist with swelling, travelling or easy removal during examinations e.g., x-ray prior to medical review, removal prior to orthotics review.

• Upper limb casts: Cut along the posterior and anterior aspect of the casts
• Lower limb casts: Cut along the medial and lateral aspect of the cast avoiding bony prominences e.g., for below knee/above knee cast, cut along the medial and lateral side of the cast, avoiding the medial malleolus (cut under) and lateral malleolus (cut over)

Adjustment

Cast adjustments are made following consultation with the surgical team. The need for adjustment may be highlighted following nursing assessment (e.g., to prevent pressure injury) or outlined by the surgical team following ward round/clinic review.

Reinforcing with synthetic material 

A POP cast may be reinforced by applying 1-2 layers of synthetic material over the cast to improve the strength and durability of the cast (see Appendix 1. Use technique outlined in full circumferential application). This is done if the cast is in the right position but needs to stay on for a longer period.

• -Reinforce the entire cast, even when only one part of the POP requires additional strength. Synthetic material is stronger than the softer POP and can cause the cast to break at the edges where the synthetic material ends
• -Take care not to make the cast too bulky or heavy. Consider replacing the whole cast if this is the case

Trimming 

A cast can be trimmed if it is too high or appears to be scratching or digging into the skin.

• Trimming is done using scissors or the oscillating saw (use technique outlined in removal)
• Felt or extra padding is applied around the edge of the cast to prevent further irritation to the skin
• The same technique is used when shortening a cast e.g., converting an above knee (AK) cast to below knee (BK), or above elbow (AE) to below elbow (BE)
• The joints must be checked for full range of movement

Extending

The cast can be extended if it is too short distally or proximally, or as requested by the team if it needs to be converted to a longer cast e.g., BK to AK or BE to AE (see Appendix 1. Use technique outlined in full circumferential application).

• To extend a cast, apply stockinette making sure it overlaps with the original cast by half of its length
• Ensure padding is even with the adjoining cast before applying the desired casting material
• Apply extra layers around the join (extending distally and proximally) to ensure structural integrity

Windows 

A window can be cut from the cast to monitor wounds or pressure injuries with the oscillating saw (use technique outlined in removal).

• When cutting a window, ensure the structural integrity of the cast remains intact
• If the cast is a little weak it can be reinforced prior to cutting the window
• Once a window is cut, the cut out will need to be placed back into the cast prior to bandaging to prevent swelling out the window

Special Considerations

Please see Appendix 1 for cast application and adjustments (including molding and wedging).

Family Centered Care

Provide education for families on:

• How to assess for compartment syndrome and pressure injuries (e.g. excessive pain unrelieved by analgesia, ensure the limb is elevated).
• How to protect the cast (keep it clean and dry- waterproof covers can be purchased online via https://www.protectacast.com.au/).
• If the patient is complaining of sweating or itchiness, a hair dryer can be used on the cool setting to relieve discomfort. Children should not put anything down the cast to help alleviate itch.
• When to re-present: The cast will need to be removed/replaced if there is suspicion of compartment syndrome, pressure injuries, infection, and loss of integrity, wet/water damage, and decrease in swelling causing the cast to become loose.
• How to prepare for removal (e.g. watch the be-positive videos (RCH TV : Fracture Clinic) and if required, give the child analgesia prior to their appointment).

Kids Health Info Fact Sheet

• https://www.rch.org.au/kidsinfo/fact_sheets/Plaster_cast_care
  
• https://webedit.rch.org.au/be-positive/A_childs_guide_to_hospital/Fracture_Clinic/

Companion Documents

• Fracture Casting Videos: https://www.rch.org.au/clinicalguide/guideline_index/Fracture_casting_videos/
  
• Paediatric Fracture Guidelines: https://www.rch.org.au/clinicalguide/fractures/
  
• Neurovascular observations- https://www.rch.org.au/rchcpg/hospital_clinical_guideline_index/Neurovascular_observations/
  
• Pressure Injury Prevention- https://www.rch.org.au/rchcpg/hospital_clinical_guideline_index/Pressure_injury_prevention_and_management/
  
• Procedural Pain Management- https://www.rch.org.au/rchcpg/hospital_clinical_guideline_index/Procedure_Management_Guideline/

Cast Application and Adjustment (Appendix 1)

Cast application and adjustment should only be done by nursing staff trained in this skill, mainly in Specialist Clinics or the Emergency Department.

Orthopaedic Fracture Casting Videos

Application

Preparing the patient

Prior to cast application consider the following:

• Check the ‘order’ is correct, and the family has consented to the procedure. If unsure about the order, check with the treatment team (e.g., orthopaedics or plastics)
• Utilise procedural pain management as required (Nursing guidelines : Procedure Management Guideline)
• Position the patient in an appropriate position so there is safe access to the limb. Ask for assistance if required to hold the limb in the right position. It is important for the limb to be in the correct position when you commence cast application as movement can create bunching in the material and increase the risk of developing pressure injuries
• Assess the skin integrity prior to commencing cast application. Creams (e.g., thin layer of moisturiser or eczema creams) and dressings (e.g., hydrocolloid, silicone or fabric tape) can be applied under the cast. Avoid using anything that will sweat or cause further skin irritation or breakdown. If the dressing requires frequent assessment a window may be cut (see above)

Backslab (half cast)

1. Gather and prepare equipment:

• Stockinette/padding
• Backslab material
• Towel or bluey
• Cool, clean water
• Crepe bandage
• Tape (e.g., Leukoplast™)
• Scissors

2. Apply stockinette or padding if required (see materials above)

3. Choose appropriate backslab material. Padded fiberglass is commonly used, however backslabs can be made from POP. Choose appropriate material width and cut to desired length. If using POP, fashion a backslab using 10-12 layers of material

4. Cut material into desired shapes (templates are available if required). Ensure edges are smooth. If using padded fiberglass, open the padding at each end to cut the fiberglass back to avoid skin irritation. Tape can be placed along the edges of the padding for extra protection

• Apply a small amount of cool clean water (20° C). If using padded fiberglass, apply water to one side of the padding, avoiding saturation. Remove excess water by rolling the splint in a dry towel or bluey and smooth the splint out before placing it on the patient
• Wrap a crepe bandage around the wrist or ankle (1-2 layers), then apply the splint to the patient's limb, and continue to wrap with the anchored crepe bandage
• Shape or mold the splint to the patient's limb for 2-4 minutes until it starts to set
• Post-application checks should be done to assess neurovascular observations, position, function, fit and integrity
• Provide education to patients and family regarding care instructions on discharge Kids Health Info : Plaster cast care

Circumferential (full cast)

Follow steps 1-5 as above

1. Gather and prepare equipment:

• Stockinette
• Padding
• Gloves
• Cast material
• Cool, clean water
• Scissors
• Moisturiser
• Sling (for upper limbs)

2. Apply stockinette over the limb and cut out excess material over concave areas to avoid pressure injuries (e.g., cut a window over the ankle or elbow). Add a stockinette for the thumb for upper limb casts

3. Apply 2-3 layers of padding. Padding should overlap 50-75% of the previous layer. It can be started at the proximal or distal end of the limb, as long as the padding is applied in a smooth and even manner. If there is gross swelling it is always best to start distally and work proximally to encourage drainage of the limb. An extra layer of padding is added at the distal and proximal end to avoid irritation from cast material. Extra padding is applied over wounds, bony prominences and the heel to prevent pressure injuries and pain on removal

4. Don non-sterile gloves, open cast material and place it in cool water no warmer than 20-25°C. The longer the material is in water, the more you squeeze it in the water, or the more water you squeeze out of it, will result in a quicker set time and less working time

5. Apply the first layer of cast material using the same technique as the padding. You can commence wrapping the material over the fracture (e.g., start at the wrist or the ankle) or you can commence at the distal or proximal end of the limb. The synthetic material should overlap but does not need to overlap as much as the padding. Avoid placing cast material beyond the border of the padding to prevent rubbing on the skin

6. Fold back the stockinette and apply a second layer of cast material in the same manner. Extra layers can be applied around the fracture, joints and load bearing areas (4-6 layers) however the rest of the cast should be 2-3 layers for ease of removal

7. Once the cast material is applied, the cast should be shaped/molded to the limb prior to the material setting to ensure the cast fits adequately. Shaping should be done with the heel of your hand (not fingertips) to avoid finger indentations and pressure injuries. Moisturiser (synthetic material) or water (POP) can be used on your gloves to prevent sticking to the material and assist with shaping

8. Apply a sling (for upper limbs) until cast completely dry and set (up to 1 hour post application)

• Post-application checks should be done to assess neurovascular observations, position, function, fit and integrity
• Provide education to patients and family regarding care instructions on discharge Kids Health Info: Plaster cast care
  

Adjustment

Molding 

Molding should only be done by nursing staff with a good understanding of fracture management. If you do not feel confident to mold, ask the surgical team for assistance. Consider the use of analgesia or sedation prior to molding as this can be a painful procedure for the patient.

Common positioning includes:

Upper Limb

• Palmar flexion – wrist pointing down
• Dorsiflexion or extension – wrist pointing up
• Ulnar deviation – wrist pointing towards the ulna
• Radial deviation – wrist pointing towards the radius
• Pronation of the forearm - palm facing downwards
• Midpronation of the forearm – palm facing towards the patient's body
• Supination - palm facing upwards as if holding a bowl of soup

Lower Limb

• Plantigrade: walking position (usually 90 degrees)
• Dorsiflexion: flexion in a dorsal direction (upwards or backwards) to the degree specified by the team
• Plantarflexion – foot pointing downwards or away (also known as Equinus)
• Inversion – Foot and ankle turned inwards (supinated)
• Eversion – Foot and ankle turned outwards (pronated)

Wedging 

A ‘wedge’ is placed in a cast to extend the position of the bone and can be performed to improve any mal-aligned fracture provided the degree of angulation isn’t too large. This is best done on POP casts rather than synthetic casts due to the adjustability of the material.

1. A line is drawn on the cast by the orthopaedic team

2. Cut a narrow line over the drawing using the oscillating saw (about 90% around the cast). The intact portion should be on the opposite side to the angulation if describing the distal fragment, or on the same side if describing the apex

3. Gently open the cast with the cast spreaders, or by hand

4. Place a wedge (piece of plastic or cork) into the opening, making sure it doesn’t come into contact with the skin. In general, the wedge size is equal to the degree of angulation required e.g., 20° angulation = 20 mm wedge. However, in reality it may be a little more due to the padding and soft tissue give

5. Wrap a layer of cast padding completely around the wedge site

6. Secure in place with tape until the check x-ray has been performed. The limb must be carefully moved until the cast adjustment is completed

7. The patient is sent to x-ray

8. If the position is correct, fill the space surrounding the wedge with POP

9. Reinforce the cast with synthetic material. If the padding is a little thin, a layer of padding can be added prior to reinforcement

For molding and wedging, parents must be instructed to monitor the patient's limb for any sign of discolouration, pain, burning, tingling or numbness. If the symptoms are not rectified within 20-30 minutes of elevation, then they must return immediately. If out of clinic hours, they must return to the Emergency Department for evaluation.

Please remember to read the disclaimer.

The review of this clinical guideline was coordinated by Mica Schneider (ANUM, Specialist Clinics). Approved by the Clinical Effectiveness Committee. First published June 2025.