Scintigraphic evaluation of tibial shaft fracture healing.

A scintigraphic study of the healing process of type A and B closed tibial shaft fractures was carried out in 40 cases treated non-operatively, comprising 32 men and eight women aged 30.6 yr on average. Scintigraphic scans were obtained with technetium methylenediphosphonate (MDP-Tc99m, 25 mCi) at 6, 12 and 24 weeks after the fracture and an activity index was calculated taking the mean of three consecutive uptake counts for both fractured and normal opposite leg, used for comparison. The results showed that the activity index in general decreased progressively from the first to the third evaluation, with little difference in behaviour between the two types of fractures. However, for B type fractures the activity index remained stable from the first to the second evaluation, followed by a marked decrease at the third evaluation, with a comparable end result for both fracture types. It was concluded that a decrease of the activity index occurs in both types of closed fractures undergoing uneventful healing and that such a decrease can be taken as a parameter for further studies which include delayed union and non-union.