Abstract
OBJECTIVES: To evaluate, using ultrasonography and the AOFAS (The American Orthopaedic Foot and Ankle Society) score, changes in the peroneal tendons of patients with ankle fractures resulting from a supination-external rotation (SER) mechanism treated with either lateral or posterolateral plate fixation. METHODS: This retrospective observational study was conducted at a tertiary level III trauma center. Adult patients (> 18 years) with unilateral SER ankle fractures, a minimum follow-up of 1 year, no persistent symptoms, and fixation using a 1/3 tubular 3.5-mm locking plate (lateral or posterolateral) were included. Exclusion criteria comprised bilateral injuries, Weber A/C fractures, pathological fractures, previous ankle disorders, infection, postoperative pain, or functional limitations. The primary outcomes were peroneal tendon thickness on ultrasonography and functional performance assessed using the AOFAS Ankle-Hindfoot Scale. Outcomes were compared between fixation techniques. RESULTS: Seventy-six patients were included (65.8% aged 35–64 years, 60.5% women, 53.9% left-sided injuries). In most cases (71.1%), tendon thickness was greater on the operated side. Posterolateral plating demonstrated a higher frequency of positive tendon-thickness differences. Most differences measured 0–2 mm (56.6%), with a statistically significant difference between lateral and posterolateral fixation groups (p < 0.001). AOFAS scores were high in both groups, indicating satisfactory postoperative functional outcomes. CONCLUSIONS: A difference in peroneal tendon thickness between the operated and contralateral sides was observed in 89.5% of patients, and these differences were significantly greater after posterolateral plating. Although plate position directly influenced postoperative tendon thickness, no clinically relevant consequences were identified. LEVEL OF EVIDENCE: Level III.