PTH and osteoarthritis: Intermittent PTH had no effect on osteoarthritis pain when PTH1R was conditionally knocked out in MSCs, as reflected by no differences in 50% PWT, PAMWT, or gait analysis between iPTH–treated and vehicle-treated Pth1r−/− mice after DMM surgery, whereas the effect of iPTH on reducing osteoarthritis pain was re-demonstrated in Pth1rfl/fl (Pth1r+/+) mice (Figure 6A–C).