This is a case report of a 58-year-old obese, diabetic female who sustained a dorsally angulated distal radius fracture, treated with a volar locking plate. Union was delayed and the plate broke. The fracture healed after repeated surgery involving replacement of the plate and grafting with demineralised bone matrix. Delayed unions of distal radius fractures are rare. This case shows that fracture treatment with locking compression plates has some specific biomechanical consequences which have to be taken into account, and special attention will be given to technical peculiarities and possible drawbacks.