Fig. 1.

Results from clinical follow-up including lameness score, carpal heat and carpal perimeter. The two-phase study design aimed to perform paired comparison between two and six months’ end-points but not along the study because both phases 1 and phase 2 carpi underwent the same procedure. Thus, data collected from both phase 1 and phase 2 carpi was used for analyses until two months. Therefore, number of radio-carpal (RC)-joints assessed for clinical parameters were n = 36 until two months (8 RC-joints control, 14 RC-joints MSC-naïve, 14 RC-joints MSC-primed), and n = 18 from two to six months (4 RC-joints control, 7 RC-joints MSC-naïve, 7 RC-joints MSC-primed). Light grey lines and asterisks correspond to control group, dark grey lines and asterisks to MSC-naïve group and black lines and asterisks to MSC-primed group. Evolution of each parameter is shown as Mean ± SEM values for each group at each time-point. Significant differences are shown between time-points within each group: time-points from Time 0 (pre-lesion) to Week 5 (just before second injection) were compared to the time of the first injection (Week 2). Subsequent time-points were compared to second injection (Week 5). a Lameness score (0–5) along the study. b Carpal heat along the study is shown as the difference between the injected carpus and the contralateral one (injected – contralateral) at each time-point (°C). For the phase 2, it was checked that local temperature had returned to basal values in phase 1 carpi and that there were no differences between opposite carpi. c Carpal perimeter along the study is shown in centimeters. Note significant reduction of carpal perimeter in groups MSC-naïve and MSC-primed on Week 3 (one week after first injection) but not in control group until Week 5. Also note the significant increase in carpal perimeter 24 h after second injection only in MSC-primed group, which is subsequently normalized (* = p < 0.05, ** = p < 0.01, *** = p < 0.001)