Computed tomography and bone scintigraphy in the evaluation of tarsal coalition

Three cases of talocalcaneal coalition were evaluated with routine radiography, conventional tomography, 99mTc-MDP bone scintigraphy, and computed tomography (CT). Routine radiography was normal in 1 case and demonstrated secondary findings suggesting coalition in 2. Conventional tomography confirmed the coalition in 2 patients. In all 3 cases, the scintigrams demonstrated increased uptake in the region of the coalition. CT provided the most graphic depiction of the coalition site and also identified an associated lesion involving the posterior subtalar joint, not recognized on conventional tomography. Scintigraphy may be useful as a screening procedure and can provide important localizing information in difficult cases.