Introduction The most common surgical treatment of traumatic spine fractures is through a posterior approach using pedicle screws and rods. Postoperative treatment protocols including the use of postoperative orthoses however differ between hospitals and surgeons. A three-point hyperextension orthosis is designed to support proper posture and unload the anterior column. Some motion remains when wearing an orthosis, and its main value in postoperative treatment is therefore believed to be pain relief and patient confidence. This could consequently shorten recovery time. On the other hand, an orthosis could also lead to muscle weakness and slow down recovery. Any orthosis-related complications might also be avoided. Additionally, recent studies on conservative fracture treatment show no difference in radiological outcomes with or without an orthosis. To date, no randomised studies have been performed on the use of postoperative orthoses. Methods and analysis Patients undergoing posterior fixation with pedicle screws for a traumatic thoracolumbar fracture (T7-L4) will be included in this randomised controlled multicentre non-inferiority trial. Forty-six patients will be randomised 1:1 to one of the two parallel groups; one group will wear a postoperative orthosis for 6 weeks followed by 6 weeks of weaning and one group will not wear an orthosis. The primary outcome is pain at 6 weeks reported on the Numerical Rating Scale. Secondary outcomes consist of pain on other moments, analgesic use, complications and length of hospital stay, quality of life (EuroQuol 5 Dimensions), back pain-related function (Oswestry Disability Index) and radiological outcomes with a follow-up of 1 year. Orthosis compliance is monitored weekly in the orthosis group. Ethics and dissemination The institutional review board (METc VUmc) approved this study on 11 October 2016 under case number 2016.389. After completion of the trial, the results will be offered to an international scientific journal for peer-reviewed publication. Trial registration number NCT03097081 and NTR6285; Pre-results.