Review Question - QID 211803

Delayed internal fixation of talar neck fractures has not been associated with increased rates of avascular necrosis.

Talar neck fractures are the most common fractures of the talus and occur after high-energy mechanisms with forced ankle dorsiflexion and axial load. The talus receives most of its blood supply in a retrograde fashion. As such, displaced fractures have a high rate of avascular necrosis, especially with higher Hawkins grade injuries. However, delayed internal fixation has not been found to increase the risk of avascular necrosis. Soft tissue stabilization can be safely utilized to minimize wound complications without significant sequelae.

Bellamy et al. performed a retrospective study of treatment outcomes of combat-related talus fractures with a mean of 12.9 days to surgical treatment. They reported a positive Hawkins sign at a mean of 7 weeks in 59% of patients with no correlation between avascular necrosis or subtalar arthritis and timing to fixation. The authors concluded that delayed internal fixation does not increase the rate of talus avascular necrosis.

Vallier et al. performed a retrospective study of 102 talar neck fractures treated with internal fixation. They reported radiographic osteonecrosis in 49% of patients, which was associated with fracture comminution (p <0.03) and open fractures (p <0.05). The authors concluded that delayed fixation of talar neck fractures did not affect avascular necrosis rate and higher energy injuries (fracture comminution and open fractures) were associated with increased avascular necrosis rates, post-traumatic arthritis, and worse functional outcomes.

Elgafy et al. retrospectively reviewed 60 talus fractures treated surgical and nonsurgical. They reported a 53.3% subtalar arthritis rate and a 16.6% avascular necrosis rate which occurred most commonly with talar body and talar neck fractures, respectively. The authors reported that clinical outcomes declined in the order of talar process fractures, talar neck fractures, and talar body fractures.

Figure A is a lateral radiograph of the left ankle with a comminuted talar neck fracture with subluxation without dislocation of the subtalar joint and no dislocation of the tibiotalar or talonavicular joints consistent with a Hawkins type IIA injury. Illustration A is a diagram depicting the Hawkins classification.

Incorrect answers:
Answer 1: Post-traumatic arthritis is the most common complication following talar neck fractures occurring in up to 50% of cases.
Answer 2: Increased fracture comminution suggests a higher energy injury mechanism, which is associated with increased avascular necrosis rates.
Answer 4: Delayed internal fixation has not been associated with increased secondary surgical procedures.
Answer 5: Increased fracture displacement is associated with increased rates of avascular necrosis due to disruption of the vascular supply.