Fractures and dislocations: the essentials
Pain relief, check nerves and pulses before and after anything you do, two views, and reduce urgently when the limb or the skin is at risk.
A 30-year-old fell from a motorcycle. His left forearm is visibly deformed and swollen. His right ankle is bent outwards, with the skin over the medial malleolus white and tight. He is in severe pain. Your senior asks you to describe the forearm X-ray on the phone and to "sort the ankle".
What do you do first, how do you describe the X-ray, and why is the ankle urgent?
- ABCDE firstLook for other injuries before the obvious one.
- Neurovascular checkPulses, capillary refill, colour, temperature, sensation and power in each nerve. Before and after every intervention.
- Skin at risk or pulseless limbReduce now, before the X-ray if needed.
- Open or closed?Open: antibiotics within 1 hour, photograph, cover. See open fractures.
- Analgesia earlyIV morphine titrated, nerve blocks where trained.
- Rule of twosTwo views, two joints, two occasions if needed.
- Describe clearlyPatient, bone, site, pattern, joint involvement, displacement, open or closed.
- Splint, elevate, referBack slab or splint, fracture clinic or orthopaedics.
- Absent pulse or cold limb
- Tented or white skin over a fracture
- Pain out of proportion (compartment syndrome)
- Wound over the fracture
- Dislocation of hip, knee or a fracture-dislocation
- Fracture in a child who can't walk yet
- Femoral or pelvic fracture with low BP
- Vascular injury
- Hip or knee dislocation
- Ankle fracture-dislocation with skin at risk
- Compartment syndrome
- A second fracture or dislocation in the same limb
- Cervical spine injury
- Child abuse
- Pathological fracture
- Commonly missed fractures (scaphoid, posterior shoulder, Lisfranc)
| Paracetamol | 1 g IV or orally every 6 hours |
| Ibuprofen | 400 mg every 8 hours with food (avoid in kidney disease, ulcers, dengue) |
| Morphine | 2.5–5 mg IV every 5 minutes to effect (child 0.1 mg/kg), with antiemetic |
| Haematoma block | Lidocaine 1% up to 3 mg/kg |
| Femoral nerve or fascia iliaca block | Hip and femur fractures, where trained |
| Hip dislocation | Reduce within 6 hours (avascular necrosis risk) |
| Knee dislocation | ABPI below 0.9: CT angiogram |
Check every dose against a current drug reference and your hospital protocol.
On this page
History
- Mechanism and energy: fall from standing, fall from height, road accident, sports, crush, gunshot.
- Time of injury. Hand dominance and job.
- Numbness, tingling, coldness.
- Other injuries, head injury, loss of consciousness.
- Pathological fracture clues: fracture after minimal trauma, cancer history, weight loss, bone pain before the injury, osteoporosis, steroids.
- Visits to a bone-setter (pehelwan) and tight bandages, common in Pakistan: they cause compartment syndrome and gangrene.
Examination
- LookSwelling, deformity, wounds, skin tenting or blanching, bruising.
- FeelPoint tenderness, joint above and below, crepitus (don't try to elicit it).
- MoveOnly as pain allows.
- NervesSensation and power in each nerve territory.
- VesselsPulses, capillary refill, colour, temperature.
- DocumentBefore and after reduction or splinting.
Describing a fracture on X-ray
- Patient and filmName, age, X-ray type, side, date.
- Bone and siteWhich bone; proximal, middle or distal third; epiphysis, metaphysis or diaphysis.
- PatternTransverse, oblique, spiral, comminuted, segmental, avulsion. Children: greenstick, buckle, plastic deformation.
- JointIntra-articular or not? Dislocation?
- DisplacementTranslation (percent of bone width), angulation (direction of the distal fragment, in degrees), rotation, shortening.
- ExtrasOpen or closed, neurovascular status. Children: Salter-Harris type for growth plate injuries.
Example: "This is an AP and lateral X-ray of the left forearm of a 30-year-old man taken today. There are transverse fractures of the middle third of the radius and ulna, with 50% translation and 20° of dorsal angulation of the distal fragments. No joint involvement. It's a closed injury and he's neurovascularly intact."
The rule of twos
| Two | Why |
|---|---|
| Two views | AP and lateral at 90°; one view can hide displacement |
| Two joints | The joint above and below (forearm and leg bones break in pairs) |
| Two sides | Compare in children (growth plates) |
| Two occasions | Repeat imaging for occult fractures (scaphoid, hip) |
| Two opinions | Ask if unsure |
Urgent reductions
- Straighten under analgesia, recheck pulses
- vascular and orthopaedic emergency if still absent
Reduce immediately, back slab, then X-ray
- Reduce within 6 hours
- check sciatic nerve
- Reduce
- ABPI
- CT angiogram if below 0.9
- Reduce early
- nerves before and after
Commonly missed injuries
| Injury | Clue |
|---|---|
| Scaphoid fracture | Snuffbox tenderness after a fall on the hand |
| Posterior shoulder dislocation | After a fit or electric shock; "light bulb" humeral head |
| Monteggia | Ulna fracture with radial head dislocation |
| Galeazzi | Radius fracture with distal radioulnar joint dislocation |
| Lisfranc injury | Midfoot pain, bruising on the sole |
| Supracondylar fracture (child) | Check radial pulse and the "OK" sign |
| Calcaneal plus spinal fracture | Fall from height onto the feet |
| Hip fracture with normal X-ray | Can't bear weight: MRI or CT |
| Maisonneuve fracture | Medial ankle injury with proximal fibula tenderness |
Complications to watch for
| Complication | When | Look for |
|---|---|---|
| Compartment syndrome | Hours to 2 days | Pain out of proportion, pain on passive stretch |
| Vascular injury | Immediate | Absent pulses, cold limb, expanding haematoma |
| Nerve injury | Immediate or after reduction | Numbness, weakness |
| Fat embolism | 1–3 days, long bone fractures | Breathlessness, confusion, petechial rash |
| DVT and PE | Days to weeks | Leg swelling, breathlessness |
| Infection | Days, open fractures | Fever, wound redness |
| Avascular necrosis | Months | Scaphoid, femoral head, talus |
| Non-union and malunion | Months | Pain, deformity |
Child abuse
Be alert to: fractures in babies who can't walk yet, posterior rib fractures, metaphyseal corner fractures, multiple fractures of different ages, skull fractures, delayed presentation, or a story that doesn't fit the injury or the child's development. Involve a senior and follow the hospital child protection process.
Treatment
Plaster advice
- Keep the limb raised above heart level for the first 48 hours. Move fingers and toes often.
- Come back immediately for increasing pain, numbness, colour change, or a plaster that feels too tight.
- Don't get the plaster wet. Don't push objects inside.
- Avoid tight bandages and bone-setters, which can cause compartment syndrome and gangrene.
- Leg plasters: ask about VTE prophylaxis per local risk assessment.
Common mistakes
- Focusing on the deformed limb and missing a head, chest or spinal injury.
- Not documenting nerves and pulses before reduction.
- Waiting for an X-ray when skin is white over an ankle fracture-dislocation.
- X-raying only one joint in a forearm or leg injury.
- Missing compartment syndrome under a tight plaster.
- Calling a fracture in a non-walking baby an accident without a senior review.
Frequently asked questions
How do you describe a fracture on an X-ray?
Patient and film details, the bone and site, the fracture pattern, whether it involves a joint, the displacement (translation, angulation, rotation, shortening), and whether it is open or closed and neurovascularly intact.
What is the rule of twos in fracture imaging?
Two views, two joints (above and below), two sides in children, two occasions for occult fractures, and two opinions if unsure.
Which fractures and dislocations need urgent reduction?
Any dislocation or fracture with a cold or pulseless limb, ankle fracture-dislocations with skin at risk, hip dislocations (within 6 hours) and knee dislocations.
What are the signs of fat embolism?
One to three days after a long bone fracture: breathlessness, low oxygen, confusion and a petechial rash on the chest, armpits and eyes.
Test yourself
Exam-style questions on this guide, from our two question banks. Choose an answer to see why each option is right or wrong.
1. What does the "rule of twos" in fracture imaging include?
Answer: Two views, two joints. Two views, the joints above and below, and sometimes two occasions.
- Two days of rest: No.
- Two splints: No.
- Two radiologists: No.
- Two doctors: No.
2. A man after a seizure has a painful shoulder held internally rotated. AP X-ray looks nearly normal. What is likely?
Answer: Posterior dislocation. Posterior dislocations follow fits or electric shocks and are easily missed; get an axillary or Y view.
- Anterior dislocation: Arm held externally rotated.
- Rotator cuff tear: Less likely.
- Frozen shoulder: Not acute.
- Clavicle fracture: No.
3. A forearm X-ray shows an ulnar shaft fracture. What else must be checked?
Answer: The radial head. Monteggia fracture-dislocation: ulnar fracture with radial head dislocation.
- Nothing more: Monteggia injury can be missed.
- The humeral head: No.
- The scaphoid only: Not the main concern.
- The clavicle: No.
4. A motorcyclist has a knee dislocation that was reduced at the scene. Foot pulses are present but weak. What must be done?
Answer: ABPI ± CT angiography. Knee dislocation (often multi-ligament injury) has a high risk of popliteal artery injury (tethered at the adductor hiatus and soleal arch) and common peroneal nerve injury, even after spontaneous reduction and with palpable pulses. Measure ABPI (< 0.9 → CT angiography) and examine serially; vascular repair within 6 hours of ischaemia. Watch for compartment syndrome after revascularisation.
- Discharge in a brace: There is a high risk of popliteal artery injury.
- Observe pulses for 24 h only: Watching pulses alone can miss an intimal injury.
- Physiotherapy referral: Physiotherapy is not the acute priority.
5. After a dashboard injury, a man’s right leg is shortened, flexed, adducted and internally rotated. X-ray shows posterior hip dislocation. What is the key priority?
Answer: Urgent reduction within 6 hours. Posterior hip dislocation (dashboard injury — knee hits dashboard): limb shortened, flexed, adducted, internally rotated; check sciatic nerve (common peroneal division — foot drop) and associated acetabular/femoral head fractures and knee injury. Reduce urgently (within 6 hours) under anaesthesia to reduce avascular necrosis; CT after reduction. Anterior dislocation: abducted, externally rotated.
- Elective reduction next week: Delay raises the risk of AVN.
- Skin traction only: Traction alone is not reduction.
- Total hip replacement immediately: Arthroplasty is not the acute treatment.
6. After a displaced intracapsular fracture of the femoral neck, the femoral head is at risk of avascular necrosis. Which artery is its main blood supply?
Answer: Medial circumflex femoral artery. Retinacular branches of the medial circumflex femoral artery run up the neck within the capsule to supply most of the femoral head. Displaced intracapsular fractures tear them, causing avascular necrosis; such fractures are usually treated by hemiarthroplasty in older patients. The artery of ligamentum teres is significant mainly in children.
- Lateral circumflex femoral artery: Contributes less, mainly to the anterior neck.
- Artery of the ligamentum teres (obturator): Important in children; minor in adults.
- Superior gluteal artery: Supplies the gluteal muscles.
- Femoral artery directly: Gives the circumflex arteries via the profunda.
7. After a fall on the outstretched hand, a young man has tenderness in the anatomical snuffbox, but the X-ray looks normal. Which bone is likely injured, and what is the main risk?
Answer: Scaphoid; avascular necrosis. The scaphoid is the most commonly fractured carpal bone. Its blood supply enters distally, so a waist fracture can cut off the proximal pole, causing avascular necrosis and non-union. Early X-rays may miss it, so the wrist is immobilised and imaged again (or MRI is done). The radial artery runs in the floor of the snuffbox.
- Lunate; carpal tunnel syndrome: Lunate dislocation can compress the median nerve, but snuffbox tenderness points to scaphoid.
- Distal radius; malunion: Colles' fracture; tender over distal radius.
- Hamate; ulnar nerve injury: Hook of hamate fracture affects the ulnar nerve.
- Trapezium; thumb base arthritis: Not the usual injury.
References and dose sources
- BOAST — arterial injuries
- NICE CG89
- NICE NG38 — fractures (non-complex)
- NICE NG37 — fractures (complex)
- Paracetamol dosing: Drugs.com: Acetaminophen (paracetamol) dosage (see also our paracetamol dose page)
- Ibuprofen dosing: Drugs.com: Ibuprofen dosage (see also our ibuprofen dose page)
- Morphine dosing: Drugs.com: Morphine dosage (see also our morphine dose page)
- Lidocaine (lignocaine) dosing: Drugs.com: Lidocaine dosage (see also our lidocaine (lignocaine) dose page)
- Ondansetron dosing: Drugs.com: Ondansetron dosage (see also our ondansetron dose page)
International guidance is linked where it reflects good practice. Where your hospital’s protocol differs, follow your hospital.