Figure 1From: Intra-articular injection of collagenase in the knee of rats as an alternative model to study nociception associated with osteoarthritisInflammation index. Joint swelling assessed by measuring knee diameters (difference between ipsilateral and contralateral knees). Collagenase-injected animals present increased knee diameters one week after injection. The number of animals per group at each time-point is indicated below the graphs. An initial number of 24 animals was used in each group. Animals were then sacrificed at different time-points for histopathology (one, two, four and six weeks; n = 6 per dose and per time-point). Mean ± SEM, two-way ANOVA followed by Bonferroni post-hoc test for comparisons between groups at each time-point. ***P <0.001, for comparisons between control and the 500 U collagenase group.Back to article page