Table 3. Synovial fluid biomarker differences between among groups and over time.

Synovial Biomarker	Comparisons	T1 (P value)	T2 (P value)	T3 (P value)
IL-8	OA vs Control	0.001*	0.003*	0.411
	OA vs Contralateral	0.010*	0.007*	0.745
	Control vs Contralateral	0.405	0.658	1
KC	OA vs Control	0.010*	<0.001*	0.096
	OA vs Contralateral	0.872	0.978	1
	Control vs Contralateral	0.001*	<0.001*	0.043*
MCP-1	OA vs Control	<0.001*	<0.001*	0.295
	OA vs Contralateral	<0.001*	<0.001*	0.043*
	Control vs Contralateral	1	1	1

Mixed linear regression model adjusted for age and weight followed by post hoc pairwise comparison with Bonferroni correction at each time point.

*Statistical significance (P < 0.05). The comparison is for control dogs (both stifles sampled), OA group with index OA stifle and the contralateral unaffected stifle.