A novel classification system for avulsion fractures of the distal fibula based on arthroscopy-assisted measurement and significance to surgery and rehabilitation.

BACKGROUND: There are difficulties in clinically diagnosing avulsion fractures of the distal fibula, although arthroscopic examination is an effective diagnostic method. To propose a novel classification scheme for avulsion fractures of the distal fibula, and further provide guidance for surgical and rehabilitation strategies. METHODS: Data from 152 patients diagnosed with avulsion fractures of the distal fibula between February 1, 2019, and April 30, 2023, were included in this study. The characteristics of avulsion fractures of the distal fibula according to arthroscopic observations were identified, and concomitant intra-articular pathology was described and recorded. RESULTS: Forty-five females and 107 males were enrolled. According to the size and relationship between the bone fragments and the ligaments, avulsion fractures were classified into the following types: A1 (n = 9 [6.0%]); A2 (n = 31 [20.3%]); B1 (n = 62 [40.8%]); B2 (n = 33 [21.7%]); C1 (n = 13 [8.6%]); and C2 (n = 4 [2.6%]). To further accurately locate avulsion fractures, fracture position was divided into anterior, junctional, and posterior areas. Most avulsion fractures occurred in the anterior and junctional areas (82.9%). Additionally, there was an association between the incidence of pathological soft tissue occupying the anterior compartment (p < 0.001), osteochondral defect (p = 0.035), and the type of avulsion fracture. CONCLUSION: This study established a new classification system for avulsion fractures of the distal fibula. Based on this classification system, we have proposed a serial management for different types of avulsion fractures, which provides certain reference value for clinical treatment.