78 Part I Chapter 3 Figure 4 SPECT/CT of a 61-year-old man after right-sided UKA in 2013 who presented with persistent knee pain on the medial side and in the patellofemoral joint, 1 year after surgery. The SPECT/CT shows (A) intensely increased BTO around the tibial part of the UKA (arrow), suspected for loosening. The normal BTO around the femoral part is also seen on A (cranially from the mentioned increased uptake). Corresponding (B) and (D) display the low-dose CT part on which positioning of the UKA-material and anatomical abnormalities of the osseous structures. Also note the (C) focally increased BTOmedial in the patellofemoral joint (arrowhead), indicating arthrosis. Image courtesy of Dr F. Paycha (Paris, France).