The Talus: A Bone with Critical Responsibilities and Poor Blood Supply

The talus — the ankle bone — is a unique structure that articulates with the tibia above (ankle joint), the calcaneus below (subtalar joint), and the navicular in front (talonavicular joint). It is entirely covered in articular cartilage except for small regions where its critical blood vessels enter. This vascular anatomy makes the talus exceptionally vulnerable to avascular necrosis (bone death from loss of blood supply) after fractures — the very injuries that most commonly disrupt its tenuous vascular supply. At Balance Foot and Ankle in Howell and Bloomfield Township, Michigan, our surgeons manage talar fractures with an understanding of their serious potential consequences and the technical demands of restoring alignment.

Mechanism and Types of Talar Fractures

The talar neck — the narrow waist of the talus connecting the body to the head — is the most commonly fractured region, accounting for approximately 50% of talar fractures. Classic mechanism: extreme dorsiflexion of the foot (as in a car accident where the foot is on the brake), driving the anterior tibial lip into the talar neck. The Hawkins classification grades talar neck fractures by displacement and subluxation of the subtalar and ankle joints — the higher the Hawkins grade, the more disruption of the talar blood supply and the higher the risk of avascular necrosis. Hawkins I (undisplaced): AVN risk approximately 10%. Hawkins II (subtalar subluxation): AVN risk 20-50%. Hawkins III (subtalar and ankle dislocation): AVN risk 50-84%.

Surgical Management

Displaced talar neck fractures require anatomic open reduction and internal fixation (ORIF) — precise restoration of alignment is critical because even small amounts of malalignment in the talar neck cause significant subtalar and ankle joint incongruity that accelerates arthritis. Fixation is performed with screws and/or plates through anterolateral and anteromedial approaches. The timing of surgery is urgent — irreducible dislocations require emergency surgery, and displaced fractures should be fixed within 8-12 hours when possible to minimize soft tissue damage and reduce infection risk from compromised soft tissue. The technical demands of talar neck surgery — visualizing and reducing a complex 3D structure while protecting fragile soft tissue and neurovascular structures — require subspecialty experience.

Prognosis and Long-Term Outcomes

The Hawkins sign — a subchondral lucent line visible on X-ray 6-8 weeks after injury — is a favorable prognostic sign indicating revascularization of the talar body and that AVN is not developing. AVN, when it develops, causes gradual collapse of the talar body with progressive ankle and subtalar arthritis. This eventual arthritis may require ankle fusion or total ankle replacement. The high complication rate of talar neck fractures — AVN, post-traumatic arthritis, malunion, and wound complications — reflects the technical challenges of this fracture type and the vulnerability of the talus’s blood supply. Long-term follow-up with weight-bearing X-rays is essential for any patient who has sustained a displaced talar fracture. Contact Balance Foot and Ankle at (810) 206-1402 for comprehensive talar fracture evaluation and management.

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Balance Foot & Ankle — Howell & Bloomfield Township, MI

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Dr. Tom Biernacki, DPM

Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.