Tissue isolation
The rats were deeply anesthetized with sevoflurane-oxygen mixture and euthanized by cervical dislocation on day 28 after MIA/saline injection. The entire knee joint, the ipsilateral lumbar L3‐L5 dorsal root ganglia (DRG) and the lumbar region of the spinal cord (L3-L5) were rapidly dissected. The DRGs were isolated using the last rib (T13) as a localization marker. One half of the knee was used for quantitative real-time qRT-PCR analysis of inflammatory mediators and the other half was used for redox status analysis. The tissue samples were placed in individual tubes, fresh frozen, and stored at −80°C until use.