Role of bone scanning in the management of non-united fractures: a clinical study.

Technetium-99m methylene diphosphonate (99mTc-MDP) bone scintigraphy was performed in 45 patients (42 male and 3 female) with established non-united fractures to predict the healing response to pulsing electromagnetic field stimulation therapy. The bone scans revealed 3 different scintigraphic patterns. The most frequent pattern was an increased uniform uptake of the tracer at the non-union site (group 1). The second pattern was increased activity at the bone ends with a photon-deficient area between the fracture sites (group 2a) or a generalized decrease in the radionuclide concentration in the region of bone fragments (group 2b). When the scintigraphic pattern did not fit either of the two patterns or when the presence of the cold area between the bone fragments could not be judged with certainty, it was called indeterminate (group 3). All patients underwent pulsing electromagnetic field stimulation. The healing rate was 87.5% and 42.8% in group 1 and group 3 patients, respectively. None of the group 2 patients had any evidence of healing, and they all underwent surgical exploration, revealing complicated non-unions. We conclude that 99mTc bone scintigraphy is a useful tool in determining complicated non-unions and selecting the proper therapy mode.