Review Question - QID 219156

This patient has a Type II talar neck fracture. The most common complication following this injury is subtalar arthritis.

Talar neck fractures are high-energy injuries to the hindfoot that are associated with a high incidence of talus avascular necrosis and subtalar arthritis. The risk of avascular necrosis increases with the severity of injury to the talus as classified by the Hawkins classification. Diagnosis is made with radiographs of the foot but frequently requires a CT scan for full characterization and evaluation of associated comminution. Treatment is an emergent reduction of the talus followed by internal fixation in an acute or delayed fashion. 

Vallier et al. retrospectively reviewed the rates of early and late complications after operative treatment of talar neck fractures to ascertain the effect of surgical delay on the development of osteonecrosis and to determine the functional outcomes after operative treatment of such fractures. They reported that osteonecrosis was associated with talar neck comminution and open fractures, confirming that higher-energy injuries are associated with more complications and a worse prognosis. They concluded that urgent reduction of dislocations and treatment of open injuries is important and thar proceeding with definitive rigid internal fixation of talar neck fractures after soft-tissue swelling has subsided may minimize soft-tissue complications.

Jordan et al. performed a systematic review of the published data on talar neck fractures for a better understanding of the postoperative clinical outcomes using open reduction and internal fixation stratified by Hawkins type. They reported that avascular necrosis presented in 0.00% of type I fractures, 15.91% of type II fractures, 38.89% of type III fractures, 55.00% of type IV fractures, and 26.47% of all fractures. They noted that osteoarthritis presented in 25.00% of type I fractures, 41.33% of type II fractures, 54.23% of type III fractures, 72.73% of type IV fractures, and 51.69% of all fractures. Subtalar arthritis presented in 0.00% of type I fractures, 54.29% of type II fractures, 46.43% of type III fractures, 45.45% of type IV fractures, and 44.97% of all fractures. They concluded that the malunion prevalence was 13.29% and the nonunion prevalence was 3.97% for all fractures.

Romeo et al. retrospectively reviewed whether fracture of the lateral process elevates the risk of development of radiographic subtalar arthrosis in patients with talar body and neck fractures. They reported that comminution of the inferior articular surface of the talus elevates the risk of subtalar arthritis in patients with both talar neck and body fractures. They concluded that fracture of the lateral process is a marker for injury to the talar inferior articular surface and increases the risk for the radiographic finding of subtalar arthritis in patients with talar neck fractures.

Illustration A depicts the Hawkins classification of talar neck fractures.

Incorrect Answers:
Answer 1: Avascular necrosis is a common complication following talar neck fractures but in a Type II injury, it is less common than subtalar arthritis.
Answer 3: Tibiotalar arthritis is much less common than subtalar arthritis, particularly in a Type II injury.
Answers 4&5: Varus malunion is more common and leads to decreased subtalar eversion (decreased motion with locked midfoot and hindfoot) and increased weight bearing on the lateral border of the foot.