140 Part I Chapter 5 fusion, is expected to be approximately in the range of 1 and 1.5 years [29-31]. In the aforementioned case, however, pain complaints persisted two years after arthrodesis for TCC, and performed bone-SPECT/CT revealed continued increased bone turnover in the fused joint space without bony bridging at the site of the arthrodesis is consistent with delayed or non-union after arthrodesis (Figure 14). Figure 14. Same patient as Figs 12 and 13. Two years after arthrodesis of the subtalar joint because of a talocalcaneal coalition, bone-SPECT/CT was per- formed because of persistent pain complaints. Continued increased bone turnover in especially the posterior facet and irregular persistent joint space without bony bridging at the site of the arthrodesis, laterally from the initial TCC. This is consistent with delayed or non-union after arthrodesis (with no signs of failed material). CT, computed tomography; TCC, talocalcaneal coalition. The change in uptake can be objectified semi-quantitatively by measuring the SUV in multiple time frames, in case visual assessment alone should remain indiscriminate (Figure 15) but its scan-scan reproducibility should be taken into account when interpreting this change in SUV. The example shows semi-quantitatively that the SUVmax at the site of the coalition increased from initial value of 12.8 (Figure 11 panel B) to SUVmax 22.0 (Figure 15). Thus, the combination of quantitative pre-operative and post-operative bone-SPECT/CT, was able to detect persistent pathological boneturnover at the site of the TC before and after, reflecting the change in disease activity that often reflects the patient’s reason of discomfort.