Subtalar joint pigmented villonodular synovitis misdiagnosed at the first visit: A case report

Figure 3 Magnetic resonance imaging. A and B: Sagittal T2-weighted images showed a low-intensity mass (white circle), which protruded from the subtalar joint into the posterior soft tissue; C and D: Sagittal T1-weighted images showed a low-intensity mass (orange circle) in the corresponding area. Besides that, mild degeneration of cartilage was observed in the subtalar joint, without apparent bony erosion.