1. Pseudarthrosis occurred in seven patients (12.9 per cent) of the fifty-four patients reported.

2. Fifty-one patients with idiopathic and paralytic scoliosis were analyzed in relation to the type of supplementary bone graft used in the fusion. In twenty-six patients in whom osteoperiosteal, bone-bank bone, or a combination of these two types of supplementary grafts were used, pseudarthrosis occurred in four (15.3 per cent).

3. In twenty-five patients in whom fresh, autogenous iliac-bone grafts were used, pseudarthrosis occurred once (4 per cent). This pseudarthrosis healed spontaneously with only a 14-degree loss of correction. It should be noted that by the use of fresh autogenous iliac-bone grafts, the incidence of pseudarthrosis was significantly reduced. Twenty-four of these twenty-five patients lost 15 degrees or less of correction. In twenty-three of these twenty-five patients, there was no loss greater than 6 degrees recorded after the first postoperative year.

4. A carefully performed spine fusion with use of a large amount of supplementary fresh autogenous iliac bone results in prompt formation of a massive solid fusion which is fully mature at one year.