One hundred fractures with delayed union or non-union in sixty-three men and thirty-four women were reviewed. Forty of the fractures were closed and sixty were open. Fifty-six were clean and forty-four were infected. The duration of nonunion ranged from six months to twenty-two years. The follow-up was from one to twenty-seven years. From this study there was evidence that certain factors predispose to non-union. These are severe injury, comminution of the fracture, fracture in the distal third of the tibial shaft, an open fracture, infection, open reduction, distraction, and insufficient immobilization.

Treatment in this series fell into three groups: bone-grafting in eighty-one fractures, miscellaneous operations in twelve fractures, and fibular transplantations or synostosis in seven fractures. Bone-grafting techniques were iliac slabs and onlay tibial bone grafts. Twenty-five of the forty-four infected fractures had bone-grafting. The clean fractures had better results than the infected ones. With or without infection, the iliac slabs gave a higher incidence of union than the onlay tibial grafts. Comminuted fractures in which non-union developed took longer than other types of fractures to heal.

The causes of failure after bone-grafting were infection, insufficient immobilization, and errors in technique. Fibular osteotomy and excision of the pseudarthrosis did not accelerate healing time significantly, although osteotomy was beneficial in correcting deformity. Eleven limbs were amputated because of persistent sepsis.

Union was achieved after bone-grafting in seventy-four fractures, after miscellaneous operations in seven fractures, and after fibular transplantation in three fractures. Five fractures remained ununited.