Fibular Nonunion: A Systematic Review of Incidence, Diagnosis, and Treatment Outcomes

Background: Fibular nonunion is an uncommon but clinically relevant complication following fractures or surgical procedures, often resulting in persistent pain and functional impairment. Due to its rarity, current evidence remains limited and no standardized treatment guidelines are available. Purpose: To systematically review the literature on fibular nonunion, focusing on clinical presentation, diagnostic approaches, and treatment outcomes. Methods: A systematic review was conducted in accordance with PRISMA guidelines. MEDLINE, Scopus, and Web of Science were searched up to July 2025. Studies including adult patients (≥18 years) with fibular nonunion treated either conservatively or surgically were included. Data regarding demographics, clinical presentation, and treatment outcomes were extracted and analyzed descriptively. Results: Nineteen studies comprising 183 patients were included. The mean patient age was 45.7 years, with a predominance of males (58.4%). The distal third of the fibula was the most frequently involved site (75.9%). The mean time to diagnosis was 28.6 weeks. Surgical treatment was performed in 65.6% of cases, most commonly using open reduction and internal fixation. Among studies reporting union outcomes, favorable radiographic healing rates were observed following surgical treatment. Conservative treatment was primarily reserved for asymptomatic or minimally symptomatic patients. The overall complication rate was low (3.8%), mainly consisting of minor infections and hardware-related issues. Conclusions: Fibular nonunion is an uncommon but clinically significant condition. Available evidence suggests that surgical management may represent the most consistently successful treatment strategy in symptomatic and mechanically unstable cases, while nonoperative treatment may remain appropriate in carefully selected asymptomatic or minimally symptomatic patients. However, the available literature is limited by retrospective study designs, heterogeneous populations, inconsistent outcome reporting, and variable definitions of nonunion, highlighting the need for prospective multicenter studies and standardized treatment protocols.