Incidence and nonunion rates of tibial fractures in adults with osteogenesis imperfecta: a retrospective cohort study of 402 patients with 42 fractures at an expert clinic

Background: Tibial fractures are the most common fractures seen in adults and lead to the most nonunions. Osteogenesis imperfecta (OI) is characterized by increased bone fragility and higher risk of fractures. No studies have been published on the incidence of tibial fractures and nonunions in adults with OI. This study aims to summarize the incidence of tibial fractures and nonunions in this population. Methods: A retrospective, descriptive study. All medical charts of adult patients in the OI database of our OI expert clinic were analyzed for tibial fractures between 2008 and 2020. Tibial fracture incidence, nonunion rate, treatment modality and potential risk factors were determined. Results: The database consisted of 402 patients, 34 of whom had suffered one or more tibial fractures, resulting in 42 fractures. The incidence of tibial fractures in adults with OI is 870 per 100,000 person-years. Two out of 42 fractures led to nonunion (5%). It was not possible to adjust for risk factors or type of treatment. Conclusion: There is a higher incidence of tibial fractures in patients with OI, but a nonunion rate comparable to the general population. With only two nonunions it is not possible to draw conclusions on the influence of risk factors or treatment of tibial fractures on OI.