1. Since the treatment of non-union is still of necessity empirical, we have reviewed our experience with 842 patients who had non-union of fractures in the shafts of long bones.
2. The factors predisposing to non-union include those incident to injury and to treatment. The principal predisposing factors related to the injury are exposure of the fracture site at the time of injury (open fractures), comminution, disturbance of the blood supply, infection, or any combination of these. The principal factors incident to treatment are ill-advised open reduction, infection, distraction of the bone ends, and immobilization that is either insecure, incomplete, or too briefly maintained.
3. The chief factors promoting union are osteogenesis, contact, fixation, and compression. In grafting, autogenous bone is preferable to homogenous bone.
4. Types of bone-grafting procedures best suited for individual bones and for specific locations are discussed.
5. Of the 842 patients, 790 (94 per cent) eventually obtained union, but 64 required more than one operation to do so. An analysis of the operative failures and the indications for amputation are presented.