Supination external rotation ankle fractures: A simpler pattern with better outcomes

Area of Science:

• Orthopedic Surgery
• Traumatology
• Sports Medicine

Background:

• Rotational ankle injuries are common, often classified using the Lauge Hansen system.
• Supination external rotation (SER) is the most frequent mechanism.
• Isolated stable SER2 distal fibula fractures typically receive nonoperative treatment.

Purpose of the Study:

• To compare functional outcomes of stable, low-energy SER2 ankle fractures treated nonoperatively with those of unstable SER4 fractures treated operatively.
• To evaluate the long-term functional recovery and complication rates for different severities of SER ankle fractures.

Main Methods:

• Prospective follow-up of 64 patients with nonoperatively treated SER2 fractures.
• Retrospective analysis of 93 operatively treated SER4 fibular fractures.
• Assessment using Short Form-36, Musculoskeletal Functional Assessment (SMFA), and American Orthopedic Foot and Ankle Society (AOFAS) scores at 3, 6, and 12 months post-injury/surgery.

Main Results:

• SER2 fractures showed full return to baseline function by 6 months, with all patients achieving preoperative levels.
• SER4 fractures exhibited significantly less functional recovery at 3 and 6 months (SMFA) and 3, 6, and 12 months (AOFAS).
• No significant difference in pain levels was observed between groups; SER4 group had higher rates of nonunion and delayed union.

Conclusions:

• SER2 ankle fractures are relatively benign, with functional limitations resolving within 3 months.
• Surgical fixation for unstable SER ankle fractures impacts lower extremity function for a longer duration.
• Patient counseling regarding expected outcomes for different SER fracture types is recommended.