Clinical Outcomes of Hyperplantarflexion Variant Compared With Supination External Rotation Ankle Fractures: A Matched-Cohort Analysis.

ABSTRACT

Recent literature has reported an uncategorized hyperplantarflexion variant ankle fracture characterized by a posteromedial fragment separate from the posterior or medial malleolar fragments. The current study sought to determine whether the outcomes for surgically treated hyperplantarflexion variant fractures are similar to the more common supination external rotation (SER) IV fractures. A prospective registry of operatively treated ankle fractures was queried to create 2 age- and gender-matched cohorts hyperplantarflexion variant and SER IV fractures. Each cohort had 23 patients (18 females), and matched pairs were within 2 years of age at the date of surgery. Patient demographics, comorbidities, and Foot and Ankle Outcomes Scores at minimum 12 months after the index surgery were compared. The cohorts were similar with respect to body mass index, the length of the clinical follow-up, medical comorbidities, dislocation rate, and postoperative articular incongruity (p > .05). Patient-reported outcomes demonstrated no statistically or clinically significant differences within any domain and were as follows symptoms (70.8 versus 77.8, p = .11), pain (80.7 versus 85.0, p = .33), activities of daily living (83.7 versus 89.2, p = .23), sports (67.4 versus 73.4, p = .33), and quality of life (57.3 versus 63.9, p = .24) for the hyperplantarflexion and SER IV groups, respectively. No significant differences were found in the rang`e of motion for dorsiflexion (17.7° versus 18.1°, p = .52) or for plantarflexion (48.6° versus 47.1°, p = .71). Patients treated surgically for hyperplantarflexion variant ankle fractures have similar 1-year clinical outcomes when compared with the more common SER IV fracture patterns, provided that the injury is correctly identified preoperatively and treated appropriately.