For conservative treatment of shaft fractures, the butterfly fragments that were somewhat larger in the closed intra-medullary (IM) nailing. The results of treatment were monitored using radiography separately for the weight-bearing femur and non-weight-bearing humerus.

27 from Group I and 31 from Group II. In the two groups, the displacement and angulation changes in the fragments, and the degree of improvement of these two factors, were compared using follow-up radiography.

The mean angulation of fragments in Groups I and II were 9.2° and 9.6°, and the mean degree of displacement of the fragments in Groups I and II were 16.7 mm and 21.2 mm, respectively. Follow-up radiography showed that the above factors improved in both groups. The degree of displacement was significantly lower in the normal cases than in the complicated cases (p=0.001).

Displacement and angulation gradually improved in both groups. It was found that the degree of displacement after the initial reduction is more important than the influence of anatomical position or weight bearing. This indicates that care should be taken when inserting IM nails to prevent displacement or angulation.