Summary Talar neck fractures are high energy injuries to the hindfoot that are associated with a high incidence of talus avascular necrosis. Diagnosis is made with radiographs of the foot but frequently require CT scan for full characterization. Treatment is emergent reduction of the talus following by internal fixation in an acute or delayed fashion. Epidemiology Incidence common most common fracture of talus ( 50%) Etiology Mechanism a high-energy injury is forced dorsiflexion with axial load Associated conditions ipsilateral lower extremity fractures common Anatomy Articulation inferior surface articulates with posterior facet of calcaneus talar head articulates with: navicular bone sustenaculum tali lateral process articulates with posterior facet of calcaneus lateral malleolus of fibula posterior process consist of medial and lateral tubercles separated by groove for FHL Blood supply talar neck supplied by three sources posterior tibial artery via artery of tarsal canal (dominant supply) supplies majority of talar body deltoid branch of posterior tibial artery supplies medial portion of talar body may be only remaining blood supply with a displaced fracture anterior tibial artery supplies head and neck perforating peroneal artery via artery of tarsal sinus supplies head and neck Classification Hawkins Classification Type Description AVN risk Hawkins I Nondisplaced 0-13% Hawkins II Subtalar dislocation 20-50% Hawkins III Subtalar and tibiotalar dislocation 20-100% Hawkins IV Subtalar, tibiotalar, and talonavicular dislocation 70-100% Imaging Radiographs recommended views AP lateral Canale view best view to demonstrate talar neck fractures technique is maximum equinus, 15 degrees pronated, xray 75 degrees cephalad from horizontal CT scan best study to determine degree of displacement, comminution and articular congruity CT scan also will assess for ipsilateral foot injuries (up to 89% incidence) Treatment Nonoperative emergent reduction in ER indications all cases require emergent closed reduction in ER short leg cast for 8-12 weeks (NWB for first 6 weeks) indications nondisplaced fractures (Hawkins I) CT to confirm nondisplaced without articular stepoff Operative open reduction and internal fixation indications all displaced fractures (Hawkins II-IV) Talus extrusion techniques extruded talus should be replaced and treated with ORIF ~63% of reimplanations do not require secondary procedure low incidence of infection with adequate I&D and antibiotic therapy high incidence of AVN without collapse complications post-traumatic arthritis mal-union non-union infection wound dehiscence Techniques ORIF approach two approaches recommended visualize medial and lateral neck to assess reduction typical areas of comminution are dorsal and medial anteromedial between tibialis anterior and posterior tibialis preserve soft tissue attachments, especially deep deltoid ligament (blood supply) medial malleolar osteotomy to preserve deltoid ligament anterolateral between tibia and fibula proximally, in line with 4th ray elevate extensor digitorum brevis and remove debris from subtalar joint technique anatomic reduction essential variety of implants used including mini and small fragment screws, cannulated screws and mini fragment plates medial and lateral lag screws may be used in simple fracture patterns consider mini fragment plates in comminuted fractures to buttress against varus collapse postoperative non-weight-bearing for 10-12 weeks Complications Osteonecrosis 31% overall (including all subtypes) radiographs hawkins sign subchondral lucency best seen on mortise Xray at 6-8 weeks indicates intact vascularity with resorption of subchondral bone increased risk with increasing degree of initial fracture displacement associated with talar neck comminution and open fractures delayed internal fixation is not associated with avascular necrosis Posttraumatic arthritis subtalar arthritis (50%) is the most common complication tibiotalar arthritis (33%) Varus malunion (25-30%) can be prevented by anatomic reduction treatment includes medial opening wedge osteotomy of talar neck leads to decreased subtalar eversion decreased motion with locked midfoot and hindfoot weight bearing on the lateral border of the foot