Talus Fractures

History. Establish the energy of the injury first: high-energy (motor vehicle accident, fall from height) or low-energy (sports). Then:

• Pain location - ankle, hindfoot or diffuse
• Weight-bearing - complete inability suggests a significant injury
• Time of injury - critical for planning urgent reduction
• Associated injuries - always screen for polytrauma after a high-energy mechanism
• Neurovascular symptoms - numbness, tingling, coldness

Examination. Look, feel and move, then the neurovascular status and the compartments:

• Look - swelling, deformity, skin integrity (open fracture?) and the compartments
• Feel - bony tenderness (the talar neck is palpable anteromedially); dorsalis pedis and posterior tibial pulses
• Move - passive range of motion is painful, with crepitus on manipulation
• Neurovascular - a mandatory full assessment, documenting the tibial nerve, deep peroneal nerve and sensation
• Compartments - palpate all 9 compartments of the foot after a high-energy mechanism

The acutely painful, swollen hindfoot after trauma has several mimics. A talus fracture is easily missed when attention is drawn to a more obvious injury or when plain films are read too quickly, so use the mechanism, the exact site of maximal tenderness, and CT wherever doubt remains.

Why a cast is acceptable. Osteonecrosis is uncommon without subtalar dislocation, because the blood supply is largely preserved (pooled type I rate about 10%), so a truly non-displaced fracture can be treated conservatively when follow-up is reliable. Screw fixation is the alternative, and it can often wait 24-48 hours for the swelling to settle. The goal is to maintain alignment while the fracture heals; secondary displacement can occur, so close monitoring is essential.

The goal. Urgent reduction, aiming for 6-12 hours and, for type III, within 6 hours if possible, followed by stable anatomic fixation. In the emergency department, within the first hour:

• Neurovascular examination - document pulses, sensation and motor function
• Classify - Hawkins type, open or closed
• Radiographs - AP and lateral ankle, AP and lateral foot, mortise
• Analgesia and splinting for temporary stabilisation
• Orthopaedic review - immediately for Hawkins III and IV

Closed reduction. Attempted first, at 1-2 hours, under adequate procedural sedation or general anaesthesia:

1. Longitudinal traction to disimpact
2. Plantarflex the foot to unlock the subtalar joint
3. Reduce the subtalar dislocation (usually posteromedial displacement)
4. Dorsiflex the foot to reduce the ankle joint if needed
5. Check neurovascular status after reduction

Post-reduction radiographs confirm the reduction. If it holds, splint and plan definitive ORIF. If it fails, go immediately to theatre for open reduction and temporary K-wire fixation.

Definitive fixation. Performed as soon as the soft tissues permit. Ideally this is within 24 hours of reduction and no later than 7 days, although, because the timing of definitive fixation has not been shown to drive osteonecrosis, staging it until the soft tissues settle is acceptable. The approach is anteromedial or dual (anteromedial and anterolateral), with 2-3 lag screws from the neck into the body, clear of the articular surfaces, aiming for anatomic reduction and fixation stable enough to allow early motion.

Why they do worse. Body fractures involve the weight-bearing ankle and subtalar joints, so their outcomes are poorer than those of neck fractures, and anatomic reduction does not spare them the arthritis rates set out under Outcomes. Set expectations accordingly, and consider early conversion to fusion if malreduction, nonunion or collapse occurs.

Pattern-specific points. In a coronal fracture the posterior fragment may be avascular; consider excising it if small. A sagittal fracture often needs a dual approach for reduction and fixation.

Position. Supine on a radiolucent table.

• Head secured on a donut or headrest; arms tucked or on arm boards
• Contralateral limb extended or frog-legged to allow C-arm access
• Operative leg with the hip externally rotated and the knee slightly flexed
• Padding for the sacrum and contralateral heel, and no pressure on the contralateral fibular head (peroneal nerve)
• Thigh tourniquet, sterile or non-sterile and covered by the drape, inflated to 300mmHg (or 100mmHg over systolic) for clear visualisation, and deflated after fixation to check perfusion
• Drape the entire leg from mid-thigh to toes, with the foot free for manipulation during reduction
• C-arm from the opposite side of the table; confirm AP, lateral and mortise views are obtainable before prep, and take them to confirm the starting position

Equipment.

• Implants - 3.5mm or 4.0mm partially threaded cannulated screws
• Guidewires - 2.0mm K-wires for temporary fixation and screw placement
• Drill - cannulated bit matching the screw size
• Reduction tools - pointed reduction forceps, bone hook
• Small fragment set - for a plate if there is comminution

Consent. Cover osteonecrosis (which may require fusion later), infection, nonunion (which may need bone grafting and revision), varus malunion leading to medial ankle arthritis, post-traumatic arthritis of the ankle and subtalar joints, wound complications, including skin necrosis, from the thin soft tissue envelope, and nerve injury: the sural nerve with the anterolateral approach and the saphenous nerve with the anteromedial. The rates are in the Complications section.

Anteromedial approach. The primary approach for Hawkins I-III talar neck fractures, giving direct access to the fracture and the medial talar dome.

1. Incision - start 2cm proximal to the tip of the medial malleolus and extend distally along tibialis anterior toward the navicular tuberosity, gently curved, 8-10cm depending on patient size and exposure; place it slightly anterior to avoid the saphenous vein and nerve
2. Superficial dissection - identify the great saphenous vein and the saphenous nerve that accompanies it, and retract them posteriorly; incise the deep fascia along the anterior border of tibialis anterior
3. Deep dissection - develop the interval between tibialis anterior, retracted medially, and the neurovascular bundle (anterior tibial artery and deep peroneal nerve), retracted laterally; incise the capsule longitudinally over the talar neck
4. Exposure - the neck fracture, the medial talar dome and ankle joint, and the talonavicular joint anteriorly; clear soft tissue from the fracture, retract gently because the skin is thin, and confirm the exposure with fluoroscopy

Why the interval is safe. Tibialis anterior and extensor hallucis longus are both supplied by the deep peroneal nerve, so this is not a true internervous plane. It is safe because the nerve is easily identified and protected, and it exposes the talar neck and medial dome, the critical areas for reduction and fixation.

Dual incisions. Complex fractures are approached through anteromedial and anterolateral incisions together. The second incision is itself a risk factor for wound complications.

Arthroscopic-assisted fixation. Reserved for selected reducible patterns; it is not a substitute for open visualisation of irreducible comminution. It requires deliberate limb positioning, safe portal mapping and a fluoroscopic trajectory.

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Exposure and preliminary reduction. Remove the haematoma and irrigate the fracture site. Assess comminution and bone quality, identify the neck and body as the main pieces, and approximate them with a bone hook or a K-wire joystick.

Provisional fixation.

1. Reduce the fracture under direct vision
2. Hold it with pointed reduction forceps or a K-wire across the fracture from a non-articular entry point
3. Check the reduction on AP, lateral and mortise views
4. Confirm there is no gap at the fracture medially or laterally
5. Confirm the alignment of the neck relative to the body, avoiding varus and rotation; the lateral view shows neck alignment

Acceptable reduction.

• Less than 1mm articular step-off
• No varus malalignment
• Anatomic length restored

Screw fixation. Two or three cannulated 3.5mm or 4.0mm partially threaded screws, run from the dorsal neck into the body in an anteroposterior direction and aimed posteriorly for purchase in the body, where the bone is densest. The threads must cross the fracture to give interfragmentary compression; fully threaded screws give none.

1. Place a guidewire from the non-articular dorsal talar neck toward the posterior body
2. Confirm the wire on AP, lateral and mortise views
3. Measure the wire length
4. Drill over the wire with the cannulated drill
5. Insert a partially threaded screw to compress the fracture
6. Repeat for the second and third screws, parallel or slightly divergent; converging screws weaken the fixation

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When the neck is comminuted. Hold length rather than compressing across the comminution; the reasons are set out under Varus Malunion. A contoured mini-fragment plate can buttress a comminuted lateral column while independent screws compress the reconstructible fragments; preserve attached soft tissue and the remaining blood supply.

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Final checks.

• AP, lateral and mortise fluoroscopy confirm the screw position and reduction, with the screws clear of the articular surfaces on every view
• Range the ankle and subtalar joints gently to confirm there is no block to motion, and confirm the subtalar joint is reduced if it was dislocated
• Stress the fracture gently; it should be stable to manual stress

Haemostasis. Deflate the tourniquet, cauterise bleeding vessels and inspect the wound. A drain is typically not needed after talar neck ORIF because the dead space is minimal.

Layers.

• Capsule - 2-0 absorbable suture, restoring the anatomic layers; closing it adds stability and reduces dead space
• Deep fascia - 2-0 absorbable suture
• Skin - 3-0 or 4-0 nylon interrupted vertical mattress sutures, or running subcuticular 3-0 monocryl, without tension, because any tension on the thin soft tissue risks necrosis
• Dressing - non-adherent dressing, gauze and padding

Splint. A well-padded below-knee posterior splint with the ankle in neutral immobilises the ankle and subtalar joints and controls swelling. It stays for 2 weeks, until the sutures are out and the swelling has subsided, then converts to a cast or boot. Avoid a circumferential cast initially because of the swelling risk.

The standard protocol for most talar neck fractures treated with ORIF (Hawkins I-II).

Accelerated motion for Hawkins III-IV. Early motion may promote revascularisation by creating hyperaemia. With osteonecrosis risk already substantial in these displaced patterns, the priority shifts to encouraging blood flow.