Fig. 5

Cytokine release from osteochondral injury models with synovial cell co-culture. (a) IL-6 concentrations in media from osteochondral injury models (no injury, compression, fracture) with synovial co-culture conditions (no cells, low synovitis, high synovitis). The osteochondral injury state resulted in statistical differences in IL-6 (p = 0.008), with no significant interaction from underlying synovitis (ANOVA, p = 0.671). Compared to no injury, IL-6 release was greater with compression injury (Tukey’s post-hoc, **p = 0.018) and was greater with fracture, although not statistically significant (post-hoc, ***p = 0.080) regardless of synovial cell condition. (b) IFNγ release was significantly greater for all samples with high synovitis cells compared to samples with low synovitis cells (post-hoc, *p = 0.016) or osteochondral cores cultured without synovial cells (post-hoc, **p = 0.007). All media collected after 3 days of co-culture. Data presented as mean ± SD (n = 5 per group) with statistical analysis performed using two-way ANOVA with Tukey’s post-hoc test.