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Immobilisation - Short leg backslab

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Fractures of:

Distal tibia and/or fibula


Metatarsal (for non-weightbearing management)

Contraindications (absolute in bold)



Open reduction with internal fixation

Informed consent

Verbal consent

Less complex non-emergency procedure with low risk of complications

Potential complications

Failure (reduction or immobilisation)

Thermal burns (from heat released during setting of plaster)

Neurovascular compromise



Abrasions and pressures sores (with risk of infection)

Joint stiffness

Venous thromboembolism

Procedural hygiene

Standard precautions

PPE: non-sterile gloves, apron


Plaster room or bed space


Procedural clinician and assistant


Stockinette (optional)

7.5 and 10cm cotton padding (for foot and leg)

15cm plaster for backslab (slightly wider than leg diameter)

10cm plaster for stirrup (approximately leg diameter)

Trauma scissors

Bowl of cold water

Crepe bandages



Supine or prone with assistant supporting weight of leg

Assistant maintains position of limb while proceduralist applies plaster

If supine, a towel placed under the knee can assist maintaining position

Ankle: flexion to 90 degrees (neutral position)

Subtalar joint and hindfoot: neutral inversion/eversion


Estimate plaster length by laying dry splint next to the area to be splinted (use uninjured leg)

Layers: 12-layer backslab along posterior leg, eight layers for stirrup from above midcalf to above midcalf

Distal margin: distal to metatarsal heads on plantar surface (continue beyond toes for phalangeal fractures)

Proximal margin: 2cm below head of fibula


Consider paracetamol 1g, ibuprofen 400mg and oxycodone 5mg (pain relief one hour pre-procedure)

Consider fentanyl 25-50mcg IV (pain relief pre-procedure adjusted to co-morbid status)

Consider fentanyl 100mcg (1.5mcg/kg pain relief pre-procedure adjusted to co-morbid status)


Ensure adequate analgesia prior to procedure

Inspect the extremity prior before splinting, document lesions repairing or dressing as normal

Apply stockinette to leg beyond margins of plaster (allowing folded to a smooth edge)

Apply 2-3 layers of cotton padding beyond plaster margins, proximally and then distally

Ensure heel and malleoli are well padded with padding overlapping itself by 25-50% with minimal creases

Submerge the pre-prepared dry backslab in water until bubbling stops, then remove

Squeeze out excess water, smooth on a flat surface

Apply on posterior leg starting from base of toes and extending up the leg

Submerge the pre-prepared dry stirrup splint in water until bubbling stops, then remove

Squeeze, smooth and apply above halfway up calf, under ankle and to above midcalf

Turn back padding around distal and proximal margins of plaster

Apply crepe bandage firmly over slab and fasten with tape

Gently mould plaster to patient anatomy maintaining position until hardened

Post-procedure care

Check X-ray, circulation and limb function:

Confirm fracture reduction with post-procedure X-ray

Check capillary refill and comfort (loosen crepe bandage or re-splint if required)

Check plaster is in correct position at knee and ankle

Check knee and toe movements are unrestricted

Provide plaster care instructions:

Patient is instructed not to weightbear

Elevate limb when possible (decreases pain and swelling)

Avoid applying pressure and heat to the cast

Do not wet the plaster (use plastic bag to protect plaster while in shower)

Return for assessment if damaged cast, increasing pain, numbness or skin colour changes

Provide temporary cast plaster care patient fact sheet


Proximal margin must be distal to fibula head to avoid compression of common peroneal nerve

Avoid crossing ankle joint anteriorly with the stirrup (creating a circumferential cast)

Temporary casting of open fractures requires covering open wounds with saline-moistened sterile gauze

Always use clean cold water (avoiding thermal injury and allowing for 10 minutes moulding time)

Extra padding at bony prominences avoids pressure areas (femoral condyles, fibular head and malleoli)

All backslabs are temporary requiring definitive management after two weeks (e.g. full cast)


There are a variety of splinting techniques in common emergency department practice. Indications for specific casts and recommended methods of application may vary depending on your institution. If in doubt seek local advice from an experienced provider or discuss with your orthopaedic team.

Peer review

This guideline has been reviewed and approved by the following expert groups:

Emergency Care Institute

Please direct feedback for this procedure to


NSW Agency for Clinical Innovation. Orthopaedic/musculoskeletal. Sydney: ACI; 2020. Available from

Roberts JR, Custalow CB, Thomsen TW. Roberts and Hedges’ clinical procedures in emergency medicine and acute care. 7th ed. Philadelphia, PA: Elsevier; 2019.

Dunn RJ, Borland M, O’Brien D (eds.). The emergency medicine manual. Online ed. Tennyson, SA: Venom Publishing; 2019.

Eiff MP, Hatch R. Fracture management for primary care. 3rd ed. Philadelphia PA: Saunders; 2011.

Stracciolini A. Basic techniques for splinting of musculoskeletal injuries In: UpToDate. Waltham (MA): UpToDate. 2019 April 18. Available from:

Liverpool hospital emergency department: Plaster booklet (2019)

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