The prognosis of ankle fractures: a systematic review

The aim of this study was to update the scientific evidence for ankle fracture prognosis by addressing radiographic osteoarthritis, time course and prognostic factors. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were included if they were randomized controlled trials, controlled trials or observational studies, including case series and case-control studies investigating radiologically confirmed osteoarthritis in adults with a classified ankle fracture, treated with or without surgery, with a minimum follow-up of 1 year. Also included were studies examining prognostic factors predicting radiologically confirmed osteoarthritis. Tibial plafond and talus fractures were excluded. Thirty-four studies were included examining 3447 patients. Extracted data included study type, inclusion and exclusion criteria, age, number of patients, number of fractures according to the author-reported classification method, radiological osteoarthritis, follow-up period, prognostic factors, and treatment. Severe heterogeneity was visible in the analyses (I2 > 90%), reflecting clinical heterogeneity possibly arising from the presence of osteoarthritis at baseline, the classifications used for the fractures and for osteoarthritis. The incidence of osteoarthritis was 25% (95% CI: 18-32) and 34% (95% CI: 23-45) for more severe fractures with involvement of the posterior malleolus. The severity of the trauma, as reflected by the fracture classification, was the most important prognostic factor for the development of radiographic osteoarthritis, but there is also a risk with simpler injuries. The period within which osteoarthritis develops or becomes symptomatic with an indication for treatment could not be specified.