Bimalleolar equivalent in ankle fractures long term ankle deltoid ligament repair examining the effect on functional scores

Ankle fractures, a commonly encountered condition in clinical practice, account for 10% of all fractures. Bimalleolar equivalent fractures are a common type of ankle fractures. In such injuries, a fracture of the lateral malleolus can be concomitant with the damage of syndesmosis and/or ruptures of the superficial and deep fibers of the deltoid ligament. The present study aims to examine the effect of deltoid ligament repair on ankle functional scores in bimalleolar equivalent fractures and ascertain the optimal treatment course. The patients were investigated from the hospital medical records, who were admitted to the orthopedics department of our hospital between January 2015 and June 2022, retrospectively. The adults older than 18 years of age, who were operated for the lateral malleolus fractures with or without the repair of deltoid ligament rupture, with a minimum postoperative follow-up period of 12 months, were included in our study. The study enrolled individuals who had received a diagnosis of deltoid ligament rupture through imaging techniques. The treatment options were open reduction-internal fixation for lateral malleolar fracture, deltoid ligament repair, or conservative treatment for the deltoid ligament rupture. The study excluded the patients who had a follow-up period of fewer than 12 months, conservative treatment for the lateral malleolus fracture, multi-trauma or accompanying ipsilateral lower extremity fracture or deformity, no mobilization capacity, history of previous ankle surgery, open fractures and accompanying neurovascular injury. The research was performed with a total of 53 individuals, comprising 31 male and 22 female participants who met the inclusion criteria. The study contains two different study groups, each were operated by two different surgeons. Group 1 consisted of 27 patients who underwent deltoid ligament repair and Group 2 consisted of 26 patients with a conservative treatment of deltoid ligament rupture. The Lauge-Hansen classification was utilized for the categorization of fracture types. Following a minimum of 12 months postoperatively, The American Orthopedic Foot & Ankle Society, Olerud Molander Ankle Score, and Visual Analogue Score were assessed individually. Furthermore, the study assessed demographic variables including age and gender, duration of hospitalization, duration of splint application, duration of full weight-bearing, fixation of syndesmotic joint and the incidence of posttraumatic osteoarthritis. A short leg splint was applied to all patients until the postoperative second week. On the fourteenth day, the sutures and the splints were removed, enabling both active and passive ankle flexion movements. The patients were not allowed to load on operated extremity. After the sixth week, weight-bearing was achieved with the assistance of crutches. Upon completion of the eighth week, the patients were permitted to weight-bearing activities without any support. The Mann-Whitney U test, which is a non-parametric statistical test, was performed for the statistical evaluation. The study found no significant differences among the groups in terms of age (p=0.78), gender (p=0.5), VAS (p=0.94), preoperative waiting time (p=0.38), total hospitalization (p=0.5), and cast application time (p=0.68). Additionally, there was no statistically significant difference in the presence of posttraumatic osteoarthritis (p=0.3), time to start full weight-bearing (p=0.78) and average follow-up time (p=0.15). The results indicate that there was a statistically significant difference with regard to syndesmotic joint fixation (p=0.002), AOFAS (p=0.04), and OMAS (p=0.01). The findings of our study indicate that fixation of the syndesmotic ligament complex is a more crucial factor than repairing deltoid ligament rupture to avoid ankle instability. The crucial step in managing bimalleolar equivalent ankle fractures is to assess the extent of syndesmotic ligament injury and tailor the treatment accordingly. Based on our study results, we are not suggesting the the routine repair of deltoid ligament ruptures for all individuals. Key Words: bimalleolar equivalent ankle fractures; deltoid ligament rupture