Initial management. Reduce a dislocated ankle at once, without waiting for radiographs when the foot is pale, cool or pulseless. Give analgesia and sedation, apply longitudinal traction, correct the deformity and apply a well padded backslab with the ankle neutral. Elevate the leg and repeat radiographs and a neurovascular check.
Reduction under sedation. Give ketamine 1 to 2 mg/kg intravenously over 1 to 2 minutes as a single dose. A further 0.5 to 1 mg/kg may be given after 10 minutes if needed, or 4 to 5 mg/kg intramuscularly without access.
A clinician skilled in airway care should give it, with continuous oximetry and capnography, after fasting. Avoid with raised intracranial pressure, psychosis or acute upper airway infection.
Definitive treatment. Surgery is the rule, within 24 to 48 hours if the skin is good, otherwise after 5 to 10 days when swelling settles (spanning external fixator for unstable soft tissues).
- Fix the posterior malleolus first when large (over 25% of the joint surface or any posterior subluxation or incisural involvement), through a posterolateral approach with a buttress plate or direct posterior-to-anterior lag screws, followed by the fibula plate and medial malleolus screws. This restores the incisura and may stabilise the syndesmosis.
- Small fragments (under 10 to 15%) with a stable syndesmosis may be left unfixed after fibular and medial fixation.
- Lateral malleolus: lag screw and a one third tubular or anatomical plate (3.5 mm screws).
- Medial malleolus: two parallel 4.0 mm cancellous lag screws, a tension band wire, or a buttress plate.
- Test the syndesmosis after bony fixation. Fix instability with a syndesmotic screw (3.5 mm, 3 or 4 cortices) or a suture button device.
- Postoperative: backslab then a boot. Non-weight bearing for 6 weeks, then progressive weight bearing and physiotherapy. Early movement from 2 weeks with stable fixation.
- Non-operative care is only for unfit patients, with a short leg cast for 6 to 8 weeks, accepting a high risk of loss of reduction.
Open fracture. Give intravenous co-amoxiclav 1.2 g every 8 hours (or cefazolin 2 g every 8 hours) within 1 hour of injury.
- Continue until 24 hours after wound closure for types I and II.
- For type III, continue until 72 hours or 24 hours after soft tissue cover, whichever is earlier.
- Co-amoxiclav maximum is 3.6 g daily; give every 12 hours at creatinine clearance 10 to 30 mL/min; check liver tests in courses over 7 days.
For heavy contamination or soft tissue loss add gentamicin 5 mg/kg intravenously once daily for up to 72 hours. Check creatinine daily and a level before the second dose. Avoid, or extend the interval, at eGFR under 60 mL/min/1.73 m2.
With severe penicillin allergy use clindamycin 600 mg intravenously every 8 hours (maximum 2.7 g daily) with gentamicin.
Tetanus booster 0.5 mL intramuscularly if the last dose was over 10 years ago, with tetanus immunoglobulin 250 units intramuscularly (500 units if over 24 hours since injury or heavily contaminated) when immunisation is incomplete or unknown. Debride and stabilise within 24 hours.
Operative antibiotic prophylaxis. Give cefazolin 2 g intravenously (3 g when weight is 120 kg or over) within 60 minutes before incision as a single dose. Repeat after 4 hours or blood loss over 1500 mL.
With severe penicillin allergy, give vancomycin 15 mg/kg intravenously starting 90 to 120 minutes before incision as a single dose. Check levels and creatinine in prolonged cases.
Thromboprophylaxis. Give enoxaparin 40 mg subcutaneously once daily in patients with a lower limb cast or non-weight bearing. Continue for the period of immobilisation and restricted weight bearing (usually 4 to 6 weeks), starting within 24 hours of injury or after surgery. Add mechanical prophylaxis as needed.
Use 20 mg once daily at creatinine clearance under 30 mL/min. Adjust by anti-Xa level in obesity and renal impairment. Check the platelet count on days 5 to 14 for heparin induced thrombocytopenia.
Analgesia.
- Paracetamol 1 g orally every 6 hours as needed for up to 5 to 7 days (maximum 4 g daily; 3 g daily when weight is under 50 kg, with chronic alcohol use or hepatic impairment).
- Ibuprofen 400 mg orally every 8 hours with food for up to 5 days (maximum 1200 mg daily); avoid with eGFR under 30 mL/min/1.73 m2, peptic ulcer, heart failure or anticoagulant use.
- Oral morphine 5 to 10 mg every 4 hours as needed for severe pain for up to 3 days. Start 2.5 to 5 mg with age over 75 or eGFR under 30 mL/min/1.73 m2. Avoid exceeding 60 mg in 24 hours without senior review. Monitor sedation and respiration and prescribe a laxative.
Complex regional pain syndrome prevention. Vitamin C (ascorbic acid) 500 mg orally once daily for 50 days from the day of injury (maximum 500 mg daily; the evidence is moderate). Avoid with a history of oxalate kidney stones, and limit with eGFR under 30 mL/min/1.73 m2. No routine monitoring.
Monitoring. Neurovascular status and skin every 4 hours for 24 hours. Radiographs after reduction, at 2 weeks, 6 weeks, 3 months and 12 months. Wound review at 2 weeks. Ankle range, syndesmotic alignment and posterior talar position at each visit. Arthritis at 1 year and later.
Referral and escalation. Refer every trimalleolar fracture to orthopaedics within 24 hours. Emergency referral for a pulseless or dislocated foot, open fracture, severe skin compromise or compartment syndrome.
Special groups.
- Older adults: osteoporotic bone needs locking plates or long plates, and weight bearing is usually restricted despite fixation. Assess bone health and falls.
- Diabetes: higher risk of infection, wound breakdown and Charcot arthropathy; use stronger fixation, longer non-weight bearing (8 to 12 weeks) and tight glucose control.
- Children and adolescents: triplane fractures need CT and anatomical reduction.
- Kidney impairment: avoid ibuprofen, reduce morphine doses and extend gentamicin intervals.
