Symptomatic treatment or cast immobilisation for avulsion fractures of the base of the fifth metatarsal: a prospective, randomised, single-blinded non-inferiority controlled trial

The purpose of this study was to compare symptomatic treatment of a fracture of the base of the fifth metatarsal with immobilisation in a cast. Our null hypothesis was that immobilisation gave better patient reported outcome measures (PROMs). The alternative hypothesis was that symptomatic treatment was not inferior. A total of 60 patients were randomised to receive four weeks of treatment, 36 in a double elasticated bandage (symptomatic treatment group) and 24 in a below-knee walking cast (immobilisation group). The primary outcome measure used was the validated Visual Analogue Scale Foot and Ankle (VAS-FA) Score. Data were analysed by a clinician, blinded to the form of treatment, at presentation and at four weeks, three months and six months after injury. Loss to follow-up was 43% at six months. Multiple imputations missing data analysis was performed. At four weeks and six months, symptomatic treatment proved non-inferior in terms of primary outcome. Immobilisation is no better than symptomatic treatment in the management of a fracture of the base of the fifth metatarsal when judged by PROMs. Significant loss to follow-up with this injury could be expected in longer term. Cite this article: Bone Joint J 2016;98-B:806-11.