Aetiological factors in non-union following Küntscher intramedullary nailing of the femur.

One hundred and three consecutive patients who underwent Küntscher intramedullary nailing for recent non-pathological single fracture of the femoral shaft showed 13.6% incidence of non-union. The latter complication was not significantly influenced by the type, site, and cause of the fracture nor by sex, timing of the operation, and reaming of the medullary cavity. Conversely, non-union was more common in older patients and in those who were in bad general condition prior to and at the time of operation. Similarly, non-union increased significantly when the nail was too thin, or its lower end did not reach the optimum level (2 cm higher than the joint line), when weight-bearing was started 6 weeks or less after operation and in the presence of post-operative knee stiffness. Two patients presented with broken nails and four with angulated nails in the presence of non-union. Three patients with segmental fracture of the femur showed non-union of the fracture nearer to the middle of the shaft.