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Immobilisation - Long leg backslab

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Fractures of:

Tibia and/or fibula shaft


Distal femur

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 at least two assistants


Stockinette (optional)

10cm cotton padding (slightly narrower than leg diameter)

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, sitting up at 45 degrees with two assistants supporting weight of leg

Assistants maintain position of limb while proceduralist applies plaster

A towel placed under the knee can assist maintaining position

Knee flexed to 20 degrees

Ankle flexed to 90 degrees (neutral position)

Subtalar joint and hindfoot in neutral inversion/eversion


Estimate plaster length by laying dry splint next to the area to be splinted

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

Distal margin: metatarsophalangeal joints

Proximal margin: junction of upper and middle third of posterior thigh


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 IV (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, malleoli and femoral condyles are well padded

Ensure padding overlaps 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 two-thirds of thigh

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 halfway 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 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


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)

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

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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