Only a minority of sternal fractures require osteosynthesis. Unstable non-union of the sternum is a very disabling condition which often requires treatment. The method most often used is tension-wiring. Due to loosening of the tensile strength or wire cut-out, this method often fails. We report the results of locked plate osteosynthesis of sternal non-union and displaced fractures. Over a five-year period, 12 patients have been treated using this method in a multicentre trial. Mean age at trauma was 32.8 years, the implant used in all cases was an 8-hole titanium plate, the fixation of the screws is based on the principles of angular stable fixation. In all cases the index procedure was possible, in all cases there was bony healing at follow-up examination. Multidirectional locked plating offers a reliable method for the successful treatment of sternal non-union and displaced fractures.