Review Question - QID 211594

The patient has sustained a displaced talar neck fracture with medial comminution which requires open reduction and internal fixation to restore anatomic alignment. The patient has likely sustained varus malunion which is a common deformity noted with non-anatomical reduction leading to hindfoot supination and decreased eversion.

Talar neck fractures, while uncommon, can lead to significant morbidity in the ambulatory patient. Treatment of these injuries requires prompt reduction due to the tenuous blood supply to the talus. The most common complications noted after a talar neck fracture are avascular necrosis, subtalar arthritis, tibiotalar arthritis, and varus malunion. A talus varus malunion generally occurs due to medial talar neck comminution and/or non-anatomic reduction of the injury. This deformity can lead to decreased eversion and a supination deformity causing patients to ambulate on the lateral aspect of the foot. These malunions are generally treated with a medial opening wedge osteotomy.

Fortin and Balazsy review the pathology and treatment of traumatic talus fractures. They cite that injuries to the head, neck, or body of the talus can result in permanent pain, loss of motion, and deformity. They note that failure to recognize fracture displacement (even when minimal) can lead to undertreatment and poor outcomes. They conclude that unrecognized medial talar neck comminution can lead to varus malunion and a supination deformity with a decreased range of motion of the subtalar joint.

Lindvall et al. performed a retrospective review to evaluate the long-term results (average of 74-month followup) of surgical treatment of isolated, displaced talar neck and/or body fractures with stable internal fixation in 25 patients. They noted an overall union rate of 88% regardless of surgical timing. The authors noted posttraumatic subtalar arthritis in all patients (100%) and talus osteonecrosis in 13/26 (50%) of patients. The authors concluded that a delay in surgical fixation does not appear to affect the outcome, union, or prevalence of osteonecrosis and that posttraumatic arthritis is a more common complication than osteonecrosis following operative treatment.

Figures A and B are the Lateral and AP radiographs of a displaced talar neck fracture with tibiotalar dislocation. Figures C and D are the post-reduction sagittal foot CT cuts that reveal a displaced talar neck fracture with medial comminution.

Incorrect Answers:
Answer 1: The patient does not have any radiographic signs of avascular necrosis according to the vignette.
Answer 2: Subtalar arthritis is the most common complication following talar neck fractures but the clinical appearance of the patient's foot is due to varus malunion.
Answer 3: Tibiotalar arthritis is a common complication following talar neck fractures but the clinical appearance of the patient's foot is due to varus malunion.
Answer 5: A planovalgus foot is unlikely to occur after a talus fracture, furthermore a planovalgus foot would lead to a pronation deformity.