Tips on what to do and when
Fractures of the talus are often high-energy injuries, most commonly due to high-speed motor vehicle accidents. As more and more people are surviving these accidents, the number of comminuted talar fractures is increasing, according to Alexandra K. Schwartz, MD, clinical professor and chief of Orthopedic Trauma at the University of California, San Diego.
Speaking at the 2016 Pediatric Orthopaedic Society of North America Specialty Day, Dr. Schwartz provided tips for managing talar neck fractures. "The goals are to achieve an anatomic reduction, preserve the patient's blood supply, and provide stable fixation to enable early range of motion (ROM)," she said.
When evaluating talar fractures, "it's always important to keep the blood supply in mind," Dr. Schwartz noted. These fractures have a tenuous blood supply which can be damaged from the injury, or during surgery, and lead to osteonecrosis. "The primary blood supply comes from the posterior tibial artery, which branches off to the artery of the tarsal canal and the deltoid artery. Blood supply also comes from the anterior tibial artery and the peroneal artery," she said.
Imaging routinely involves radiographs and, often, computed tomography (CT) scans. Dr. Schwartz recommends getting three radiographic views—anteroposterior, oblique, and lateral—of both the foot and the ankle. She also finds the Canale view helpful in assessing talar neck angulation and for ruling out varus malalignment intraoperatively.
When treating talar neck fractures, Dr. Schwartz advocates first attempting a closed reduction, with the patient under sedation. "It is helpful to flex both the hip and the knee, place the ankle in extreme plantar flexion, apply axial traction, and try to manually manipulate the fragments back into place," she said. "However, it is very important to avoid repeated attempts at this because you can actually do more harm."
According to Dr. Schwartz, although not all talar neck fractures are orthopaedic emergencies, immediate treatment is required when any of the following is present:
- skin threat
- neurologic compromise (eg, the tibial nerve)
- vascular compromise
- open fractures
Open fractures represent approximately 25 percent of all talar neck fractures and are associated with high rates of osteonecrosis and deep infection, Dr. Schwartz noted. "Open talar neck fractures, therefore, require thorough and immediate débridement," she stressed. "The decision can then be made whether to provisionally stabilize the fracture with an external fixator if the patient is hemodynamically unstable or the surgical environment is not ideal, or to definitely treat it."
Surgical treatment of talar neck fractures involves either percutaneous or open fixation. According to Dr. Schwartz, percutaneous fixation should only be performed on truly nondisplaced fractures to provide early range of motion and avoid late displacement.
"During percutaneous treatment, screws can be placed anteriorly to posteriorly—although this is somewhat challenging due to the talonavicular (TN) joint—or the screws can be placed through a 1 cm vertical incision just lateral to the Achilles tendon," she explained. "When looking at the screw construct, anterior-to-posterior screws are very difficult to place perpendicular to the fracture line because of the TN joint. Posterior-to-anterior screws allow for more perpendicular placement and are, therefore, biomechanically stronger."
Dr. Schwartz stressed that open reduction and internal fixation (ORIF) is indicated for all displaced talar neck fractures, and she advocates using a dual-incision approach (anterior lateral and anterior medial) to ensure anatomic alignment. "It's very difficult to judge rotation and varus/valgus adequately with just one incision," she said.
She added that mini fragment screws and plates have become an adjunct in stabilizing these fractures. "Use of a lag screw may overcompress areas of comminution, which can lead to malreduction," she cautioned. "Smaller plates can actually span the comminution, thereby maintaining the reduction."
Dr. Schwartz's disclosure information can be accessed at www.aaos.org/disclosure
Maureen Leahy is assistant managing editor of AAOS Now. She can be reached at email@example.com
- The incidence of comminuted talar fractures is increasing.
- Open talar neck fractures and those with neurologic compromise, vascular compromise, or skin threat should be treated emergently.
- ORIF is indicated for all displaced talar neck fractures.
- A dual-incision approach should be used and care taken to avoid overcompressing comminuted fractures.