Figure 1

Changes in osteoarthritis cartilage volume percentage of loss from baseline after 24 months for each patient for the global knee and medial compartments of the three subgroups identified in the cluster analysis: slow (n = 48), intermediate (n = 48), and fast (n = 11) progressors. The global (and medial) volume loss at all the different time points were -2.3 ± 0.4% (-3.2 ± 0.6%) for the slow progressors, -7.2 ± 0.6% (-9.9 ± 0.1%) for the intermediate progressors, and -13.2 ± 0.4% (-21.5 ± 0.1%) for the fast progressors; the intermediate and fast progressor subgroups were found to be statistically significant when compared to baseline (t test). *p < 0. 001; **p < 0.0001.