Functional outcomes of unstable ankle fractures with and without syndesmotic fixation in the adolescent population

Purpose: The purpose of this study was to compare functional outcomes of adolescents with and without ankle syndesmotic injuries and identify predictors of functional outcome after operative ankle fractures. Methods: A retrospective review was conducted on operative adolescent ankle fractures treated between 2009 and 2019 with a minimum of one-year follow-up (mean 4.35 years). Patients who underwent syndesmotic fixation (SF) (n = 48) were compared with operative ankle fractures without syndesmotic injury (n = 63). Functional outcomes were assessed using standardized questionnaires, specifically the Foot and Ankle Ability Measure (FAAM) and Single Assessment Numerical Evaluation. Results: There were no differences in patient-reported outcomes, rates of return to sport or complications between groups with and without SF. The SF group had a longer tourniquet time (p = 0.04), duration of non-weight-bearing (p = 0.01), more Weber C fibula fractures (p < 0.001), fewer medial malleolus fractures (p = 0.03) and more frequently underwent implant removal (p < 0.0001). Male sex, lower body mass index (BMI) and longer duration of follow-up were significant predictors of a higher FAAM sports score using multivariable linear regression. SF was not a predictor of functional outcome. Conclusion: This study demonstrated that patients that undergo surgical fixation of syndesmotic injuries have equivalent functional outcomes compared to operative ankle fractures without intraoperative evidence of syndesmotic injury. We also identified that male sex, lower BMI and longer duration of follow-up are predictors of a good functional outcome. Level of Evidence: III

Four-Dimensional CT Analysis of Normal Syndesmotic Motion

Background: The syndesmosis ligament complex stabilizes the distal tibiofibular joint while allowing for small amounts of physiologic motion. When injured, malreduction of the syndesmosis is the most important factor that contributes to inferior functional outcomes. Syndesmotic reduction is a dynamic measure, which is not adequately captured by conventional computed tomography (CT). Four-dimensional CT (4DCT) can image joints as they move through range of motion (ROM). The aim of this study was to employ 4DCT to determine in vivo syndesmotic motion with ankle ROM in uninjured ankles. Methods: Uninjured ankles were analyzed in patients who had contralateral syndesmotic injuries, as well as a cohort of healthy volunteers with bilateral uninjured ankles. Bilateral ankle 4DCT scans were performed as participants moved their ankles between maximal dorsiflexion and plantarflexion. Multiple measures of syndesmotic width, as well as sagittal translation and fibular rotation, were automatically extracted from 4DCT using a custom program to determine the change in syndesmotic position with ankle ROM. Results: Fifty-eight ankles were analyzed. Measures of syndesmotic width decreased by 0.7 to 1.1 mm as the ankle moved from dorsiflexion to plantarflexion ( P < .001 for each measure). The fibula externally rotated by 1.2 degrees with ankle ROM ( P < .001), but there was no significant motion in the sagittal plane ( P = .43). No participants with bilateral uninjured ankles had a side-to-side difference in syndesmotic width of 2 mm or greater. Conclusion: 4DCT allows accurate, in vivo syndesmotic measurements, which change with ankle ROM, confirming prior work that was limited to biomechanical studies. Side-to-side syndesmotic measurements are consistent within subjects, validating the method of templating syndesmotic reduction off the contralateral ankle, in a consistent ankle position, to achieve anatomic reduction of syndesmotic injury. Level of Evidence: Level II.

Hybrid Fixation for Danis-Weber Type C Fractures With Syndesmosis Injury

Background: This study aimed to assess the clinical and radiological outcomes of hybrid fixation for Danis-Weber type C ankle fractures with a syndesmotic injury. Methods: From January 2016 to April 2018, we retrospectively reviewed consecutive patients who underwent hybrid fixation for Danis-Weber type C ankle fractures with syndesmotic injury with a minimum follow-up of 12 months. We excluded patients who achieved syndesmosis stability after fracture fixation. In all patients, we allowed partial weightbearing at 4 weeks postoperatively. We evaluated the visual analog scale for ankle pain, the Olerud-Molander ankle score, and the American Orthopaedic Foot & Ankle Society score. Malreduction of the syndesmosis was defined based on 2 previously reported methods. Fourteen patients (11 men and 3 women) were included in this study. There were 11 patients with pronation external rotation-type fractures and 3 patients with Maisonneuve fractures. The average age at operation was 37.2 years (range, 18-70 years). Results: Clinical scores were significantly improved at the last follow-up. Postoperative malreduction was observed only in 1 patient (7.1%). Conclusion: Hybrid fixation using a suture-button device combined with a syndesmotic screw in Danis-Weber type C fractures with syndesmosis injury showed a high accuracy of reduction, a low rate of diastasis, and favorable clinical outcomes. This combined method could be a good alternative treatment option for Danis-Weber type C ankle fractures with a syndesmosis injury. Level of Evidence: Level IV, case series.