Imaging evaluation of periprosthetic loosening: A primer for the general radiologist

Figure 3 Triple phase bone scintigraphy and magnetic resonance imaging demonstrating loose femoral component. The above case displays the importance of planar bone scintigraphy and magnetic resonance imaging (MRI) with multi-acquisition variable resonance image combination selective sequencing in the diagnosis of periprosthetic loosening. The patient in this case had presented 4 years following bilateral primary total hip replacements with discomfort in the right hip only. A and B: Initial plain radiographs were unremarkable, therefore higher order imaging in the form of planar bone scintigraphy (A) and MRI (B) were acquired. Marked increased uptake of the technetium-99m MDP radiotracer in the region of the right greater trochanter and shoulder of the femoral component was noted (yellow arrows). Physical examination findings of a soft tissue mass and raised inflammatory markers prompted the acquisition of MRI for further characterisation. MRI findings of a soft tissue collection (blue arrows) led to the diagnosis of septic loosening in this patient. This was later confirmed intraoperatively during revision surgery.