O2126: Transitional Ankle Fractures: Selecting for Success in Emergency Department Closed Reduction

Background: The purpose of this study was to examine pediatric patients with transitional ankle fractures (triplane or Tillaux) and determine risk factors associated with failed closed reduction (CR) in the emergency department (ED).

Methods: A retrospective review of all patients treated for distal tibial fractures at a single institution between 2004 and 2021 was conducted. Patients were identified using fluoroscopy logs of all lower extremity injuries presenting to the ED that required CR. Injury images were reviewed, and the fracture pattern was determined using the Salter-Harris classification. Patients were 18 years-old or younger with an open/closing but not closed distal tibial physis at time of injury and had an attempted CR in the ED. X-rays were analyzed separately by two independent reviewers. Measurements of articular surface gap, maximum displacement of the metaphysis, and anterior displacement off the Tillaux fragment were recorded at three time points (pre-reduction, immediate post-reduction, and final follow-up in clinic). Statistical analysis was performed and paired t-tests and Mann-Whitney tests were reviewed.

Results: A total of 196 patients were reviewed; seventy-six patients were included (63 with triplane fractures and 13 with Tillaux fractures) with a mean follow-up of 24.5 weeks (range, 1.9 to 126).
A conservative cohort consisting of 39 patients that were successfully treated with closed reduction and immobilization were compared to 37 patients that required operative fixation (OF). The average time to closed reduction in the conservative cohort was 24.9 (1-96) hours compared to 25.8 (1-48) hours in the surgical cohort. (p=0.053) This approached but did not reach statistical significance.
12/15 (80%) patients that were placed into short leg immobilization after CR required operative fixation (OF) whereas only 25/61 (41%) of patients required OF that were placed into long leg immobilization (p=0.005). Short Leg immobilization was shown to 5.7 times more likely to result in operative fixation (p=0.01, OR=5.7, 95% CI [1.6-27.2]).
Patients that required surgery also had a statistically higher average pre-reduction articular surface gap 3.84 (1-10.7) mm compared to an average pre-reduction articular surface gap of 2.13 (0-6.7) mm (p= 0.001) in patients that were successfully treated with CR. Multivariate regression analysis adjusting for pre-reduction articular surface gap and use of short leg immobilization demonstrated independent predictors of requiring operative fixation (p=0.006, OR=8.8, 95% CI [2.1-49]).

Conclusion: Half (37/76 (49%)) of patients with transitional ankle fractures that were treated with closed reduction and immobilization in the ED ultimately required operative fixation. Patients that had both a larger average pre-reduction articular surface gap and were placed into short leg immobilization were over eight times more likely to require operative fixation.