Abstract
Introduction
Many surgeons assess biological activity of fracture nonunion by the presence or absence of callus using radiograph. However, it is difficult to assess biological activity only by radiographic appearance. Bone scintigraphy reflects blood supply and bone metabolism and is possibly useful to assess biological activity in nonunion cases.
Hypothesis
We hypothesized that poor callus visualization did not always mean lack of biological activity.
Materials & Methods
Retrospective assessment and comparison of radiographs and Tc-99m bone scintigraphy of 44 patients with uninfected nonunion was done.
Results
Uptake was observed at or around the nonunion site in all cases. Three patterns of uptake were noted; Spot type (S): intense uniform uptake, Uneven type (U): uptake with distribution from cold to hot, and Cleft type (C): decreased uptake surrounded by significant uptake on both sides. All 9 cases of hypertrophic nonunion demonstrated the S type. In 21 cases of oligotrophic nonunion, there were 12 S, 5 U and 4 C. In 3 cases of comminuted nonunion, there were 1 U and 2 C. In 5 cases of defect nonunion, there were 1 U and 4 C. In 6 cases of atrophic nonunion, there were 2 U and 4 C.
Discussion & Conclusions
Our results suggest that poor callus visualization does not always mean lack of biological activity. The distribution of uptake and the cleft with decreased uptake are helpful findings to assess the necessity of bone graft or other supplementation in nonunion surgery.
