Classification of ankle injury on radiography and magnetic resonance imaging: study protocol for a retrospective, self-controlled, clinical trial with 3-month follow-up

Abstract

Background: Radiography is commonly used for investigating ankle injury, but is inadequate for diagnosing some ankle fractures and ligamentous injuries. Thus, radiography cannot be used for accurate fracture classification or to formulate a treatment program. In contrast, magnetic resonance imaging can clearly show occult ankle fractures and ligamentous injuries, and can diagnose fracture combined with ligamentous injury. Therefore, radiography combined with magnetic resonance imaging may potentially be adequate for fracture classification and postoperative evaluation. Methods/Design: We conducted a retrospective, single-center, self-controlled, clinical trial with 3-month follow-up at the First Hospital, Hebei Medical University, China. Sixty-eight patients with ankle injury received internal fixation for fracture and ligament repair. The site of fractures was determined using radiography plus magnetic resonance imaging. Ankle fractures were categorized preoperatively using the Lauge-Hansen classification. We then defined imaging evaluation criteria, which were used to assess ankle fractures postoperatively. The primary outcome was the percentage of patients with an excellent outcome according to the evaluation criteria at postoperative 3 months. The secondary outcomes were the preoperative Lauge-Hansen classification; fracture repair as evaluated by radiography plus magnetic resonance imaging preoperatively and 3 months postoperatively. Other outcome was incidence of adverse events at postoperative 3 months. Results demonstrated that 53% of patients had an excellent outcome according to the evaluation criteria at postoperative 3 months. The numbers of patients with excellent, good and poor outcomes were 36, 23 and 9, respectively. In accordance with the Lauge-Hansen classification, there were 7 cases of pronation-abduction, 14 cases of pronation-external rotation (pronation-eversion), 13 cases of supination-adduction, and 35 cases of supination-external rotation (supination-eversion). The incidence of adverse events at postoperative 3 months was 17%. Discussion: This study analyzes the feasibility of radiography combined with magnetic resonance imaging for ankle fracture classification and postoperative evaluation to provide an accurate clinical basis for repair of ankle injury. Trial registration: ClinicalTrials.gov identifier: NCT02964754. Ethics: The study protocol has been conducted in accordance with the Declaration of Helsinki, formulated by the World Medical Association. Informed consent: Written informed consent was obtained from all participants.