Sixteen cases of fracture of the femur and tibia on the same leg in children below 16 year age were treated in Soonchunyang Univ. Hospital during the period 1988-1993. We studied all of these patients, classified by LettsNew classification of pediatric floating knee, retrospectively with analysis of treatment and results.

The results were as follows;

1. Among the 16 cases,14 cases were male(88%), and 10 cases(63%) were at their first decade and 6 cases(37%) were at second decades.

2. The main cause of injury was traffic accident;15 cases(94%).

3. The most common concomitant injury was fracture in other site;5 cases(31%).

4. Among the 9 cases of conservative treatment, limping and leg length inequality were occurred in 6 cases(61%), and malunion in 5 cases(56fo).

5. Among the 7 cases of operative treatment, limping was occurred in 1 cases(14%), leg length inequality was in 2 cases(29%), and malunion in 3 cases(43%).

6. Among the 10 cases at first decade, limping was occurred in the 6 cases(75%) out of 8 cases of conservative treatment, but it was not occurred in 2 cases of operative treatment.

According to the results, we suggest that at least one fracture should be rigidly fixed in all cases.