case_images: PMC5387828_01
case_images: Anteroposterior (a) and lateral (b) plain radiographs of the left ankle showing a radiolucent lesion with marginal sclerosis in the talar neck (arrow-heads).
case_images: CRIOR2017-2171627.001.jpg
case_images: PMC5387828_01_CRIOR2017-2171627.001.jpg
case_images: fig1
case_images: Plain radiographs showed a small exostotic bony bulge on the talar neck which resembled a traction spur and a recess on the talar neck (Figure 1).
case_images: Axial (a) and sagittal (b) computed tomography images of the left ankle showing central calcification within a radiolucent lesion of the talar neck.
case_images: CRIOR2017-2171627.002.jpg
case_images: PMC5387828_01_CRIOR2017-2171627.002.jpg
case_images: fig2
case_images: Computed tomography (CT) showed an 8 mm radiolucent lesion with marginal sclerosis and central calcification in the talar neck (Figure 2).
case_images: T1-weighted (a) and short T1 inversion recovery (b) sagittal magnetic resonance imaging showing a bone lesion in the talar neck with surrounding bone marrow edema and synovitis in front of the bone lesion.
case_images: CRIOR2017-2171627.003.jpg
case_images: PMC5387828_01_CRIOR2017-2171627.003.jpg
case_images: fig3
case_images: Magnetic resonance imaging (MRI) revealed a bone lesion in the talar neck with surrounding bone marrow edema, synovial thickening in front of the bone lesion, and joint effusion (Figure 3).
case_images: (a) Arthroscopy of the left ankle joint. Hyperplasia with hyperemia of the joint synovium was noted. (b) After synovectomy, a red subperiosteal lesion was seen through the thinned cortex of the talar neck.
case_images: CRIOR2017-2171627.004.jpg
case_images: PMC5387828_01_CRIOR2017-2171627.004.jpg
case_images: fig4
case_images: Arthroscopy revealed capillary hyperemia and synovial hyperplasia in the anterior aspect of the ankle joint (Figure 4(a)). The surface of the OO lesion was suspected after exposure because the overlying cortex was irregular and too thin to exhibit evidence of denting under gentle pressure with a probe (Figure 4(b)).
case_images: Intraoperative 3D C-arm-based axial reconstructed imaging before (a) and after (b) tumor resection. (a) Precise detection of the nidus was achieved before destruction of the cortex. (b) Complete tumor resection and appropriate bone preservation were confirmed intraoperatively.
case_images: CRIOR2017-2171627.005.jpg
case_images: PMC5387828_01_CRIOR2017-2171627.005.jpg
case_images: fig5
case_images: We then used 3D C-arm-based imaging (ARCADIS Orbic 3D, Siemens Medical Solutions, Erlangen, Germany) to verify the lesion's exact location and visualize the exact extent of the nidus without removal of large part of cortex (Figure 5(a)) and used grasping forceps and curettes to remove it. A final 3D scan was performed to confirm that the nidus was completely removed (Figure 5(b)).