Dual-incision open reduction and internal fixation for displaced talar neck and body fractures | advanced
Surgical Imaging
Location: Runs in the tarsal canal between the flexor digitorum longus and posterior tibial tendons, entering the talus posteromedially. The deltoid branch arises from it and supplies the medial talar body.
Risk: During the anteromedial approach the deltoid branch is vulnerable when dissecting around the posteromedial talar body or when performing medial malleolar osteotomy. Excessive medial retraction or osteotomy malposition can transect this vessel and increase AVN risk.
Location: The dorsalis pedis artery and deep peroneal nerve lie in the interval between extensor hallucis longus and extensor digitorum longus at the ankle joint level, then course laterally over the talar neck.
Risk: In the anterolateral approach these structures are directly in the field. Overzealous retraction or placement of retractors under the extensor retinaculum can cause neuropraxia or arterial injury. Identify and protect with vessel loops before exposing the lateral talar neck.
Location: The superficial peroneal nerve divides into intermediate and medial dorsal cutaneous branches approximately 6-8 cm proximal to the ankle joint; the intermediate branch crosses the anterolateral ankle at the level of the talar neck.
Risk: A vertical anterolateral incision placed too far laterally risks transection of the intermediate dorsal cutaneous branch, causing painful neuroma and sensory loss on the dorsum of the foot. Place the incision just lateral to the extensor digitorum longus and identify the nerve proximally.
Type II vs Type III: The distinction is whether the subtalar joint is dislocated (Type III) or merely subluxated (Type II). Misclassification changes the quoted AVN risk from 20-50 percent to 50-100 percent and alters urgency of reduction.
Type IV: Any tibiotalar dislocation with talar neck fracture qualifies as Type IV. This carries the highest AVN risk and often involves talar head or lateral process comminution that must be addressed.
Mechanism: Inadequate visualisation of the medial talar neck leads to persistent varus angulation during reduction. The talar neck is wider medially; comminution here allows the head to rotate into varus if not supported.
Consequence: Greater than 5 degrees of varus malunion produces lateral column overload, subtalar incongruity, and post-traumatic arthritis in greater than 70 percent of patients within 5 years. Dual-incision exposure is mandatory to prevent this.
Indication: Most displaced talar body fractures require an osteotomy to visualise the posteromedial talus. The osteotomy must be predrilled with two parallel 2.0 mm drill holes before completing the cut.
Risk: Failure to predrill leads to loss of reduction after the osteotomy; the malleolar fragment cannot be accurately repositioned. The osteotomy should exit at the plafond level, preserving the deltoid ligament attachment.
H.A.W.K.I.N.S.HAWKINS — Classification and AVN Risk
T.A.L.U.S.TALUS — Dual-Incision Approach and Fixation
Surgical Indications
Absolute Indications
- Displaced talar neck fracture (greater than 2 mm displacement or any angulation)
- Any talar neck or body fracture with tibiotalar or subtalar dislocation (Hawkins II-IV)
- Open talar fracture (Gustilo-Anderson II or III)
- Associated compartment syndrome of the foot
Relative Indications
- Minimally displaced talar neck fracture in a young active patient (to prevent late arthritis)
- Talar body fracture with greater than 1 mm articular step-off
- Hawkins Type I fracture with high-energy mechanism and significant soft-tissue swelling (to allow early motion)
Contraindications
Absolute:
- Medically unstable patient for surgery
- Active infection at surgical site
- Severe peripheral vascular disease precluding wound healing
Relative:
- Hawkins Type I fracture in low-demand elderly patient (consider non-operative management with close radiographic follow-up)
- Severe osteoporosis precluding stable fixation
- Delayed presentation greater than 3 weeks with established malunion
Evidence for Timing and Approach
Timing of Reduction
- Emergent closed reduction of any dislocated talus is mandatory within 6 hours of injury. Vallier (2004) demonstrated that delay beyond 6 hours significantly increases AVN risk in Type II and III fractures.
- Open fractures require urgent debridement and provisional stabilisation within 6-12 hours.
Dual-Incision Approach
- Single medial or lateral approaches provide inadequate visualisation of the contralateral column and lead to higher rates of varus malunion (greater than 15 percent).
- The combined anteromedial plus anterolateral approach allows direct assessment of reduction at both the medial and lateral talar neck cortices and the subtalar joint.
Fixation Constructs
- Biomechanical studies show two parallel cannulated screws provide adequate stability for simple neck fractures; comminuted fractures or body fractures benefit from supplemental mini-fragment plate fixation on the medial or lateral column.
- Headless compression screws or countersunk headed screws are required to avoid impingement on the talonavicular joint.
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A 32-year-old male sustains a Hawkins Type III talar neck fracture with subtalar dislocation after a fall from height. The talus is dislocated posteromedially. How do you manage the injury in the first 6 hours?”
“You are planning ORIF for a displaced talar body fracture. The posteromedial fragment is not adequately visualised through standard anteromedial and anterolateral incisions. What additional exposure do you use and how do you perform it safely?”
“A 28-year-old patient undergoes ORIF of a Hawkins Type II talar neck fracture. At 6 weeks the AP radiograph shows a subchondral lucency beneath the talar dome (Hawkins sign). What does this finding mean and how does it influence your management?”