ORTHOPHEADICS, Etchebehere ECSC

Abstracts XIX Brazilian Congress of Nuclear Medicine

8. ORTHOPHEADICS

8.2 - CONGENITAL SHORT FEMUR : IS BONE SCINTIGRAPHY A PREDICTOR OF OUTCOME OF ELONGATION TREATMENT?

Etchebehere ECSC, Grigolon MV, Ramos CD, Santos AO, Lima MCL, Belangero W, Camargo EE. Division of Nuclear Medicine, Department of Radiology and Department of Orthopedics and Traumatology, Campinas State University (UNICAMP), Campinas, Brazil.

elba@mn-d.com

Congenital short femur is the most common longitudinal growth deficit of the femur. Treatment is based on femoral elongation by external fixation, but the prediction of patient outcome is difficult. The purpose of this study was to evaluate the usefulness of bone scintigraphy as a prognostic tool after femoral elongation in patients (pts) with congenital short femur. Five pts with congenital short femur, ages ranging from 5 to 14 years, 3 males and 2 females, were studied. Pts underwent surgery with placement of a Lazlo-Cañadel elongator. Pts were evaluated clinically and submitted to an elongation of 2 mm per day. Three phase bone scintigraphy studies were performed 1, 2 and 4 months after surgery. Pts received an intravenous injection of 7.4 MBq/kg (0.2 mCi/kg) of [Tc-99m]MDP. Three-phase bone scintigraphy was performed in the supine position in a scintillation camera with a LEAP collimator. For the blood flow and equilibrium phases pts were positioned with the elongation region in the center of view. For interpretation, the amount of radioactivity present in all three phases was used and graded as absent, mild, moderate and marked activity. Scintigraphic data were correlated with the clinical outcome. Pts with moderate or marked uptake in the delayed images had a favorable outcome. In contrast, pts with mild or no uptake in the delayed images had an unfavorable outcome. Blood flow and equilibrium images were less important than the delayed images in the prognostic evaluation of these pts.

Three-phase bone scintigraphy can be used to as a predictor of the outcome of treatment with elongation in pts with congenital short femur.