- To determine whether the use of a PEMF stimulation device as adjunct therapy for acute tibial shaft fractures increases the radiological and clinical union rates at 12, 26 and 52 weeks after injury. A fracture will be deemed to have radiologically united at these times if by independent observation, two orthopaedic consultants agree that three bony cortices are bridged by bony callus on an anteroposterior and lateral plain X-ray at these times. If the two reviewers disagree, a third opinion will be sought which will be final. A fracture will be deemed to have clinically united if it is deemed stable under clinical examination by the treating orthopaedic surgeon at these times.