We used llizarov apparatus for the chronic infected nonunions or nonunions with large bone defect to achieve union, to correct deformity, to eradicate infection and to eliminate bone defect. Twenty-eight patients were treated for nonunions of long bone with llizarov apparatus by the same surgeon between 1990 March and 1992 August.

Followings are the summary of the results.

1. 21 patients achieved solid bony union. The average duration of application of apparatus was 10.12 months.

2. 8 patients with less than 2cm shortening were treated by monofocal compression osteosynthesis, with an average healing time of 6.3 months. None of these 8 cases had infection.

3. 14 patients with infection and less than 2cm bone defect were also treated by monofocal compression osteosynthesis, with an average healing time of 8.7 months.

4. 6 patients with more than 2cm shortening or bone defect were treated by bone lengthening or bone transport. The average length gain was 5.6cm.

5. We have not any significant complications with llizarov method. The most common complication was a superficial pin tract infection in 12 patients(43%).

6. If the bony defect was not large, it was thought to be better to change B, or B, type nonunion to B, type to improve bony contact and healing.

We find ourselves capable of solving increasingly more difficult problems with a level of sucess rarely, if ever, achieved with other conventional method.