LPS induces PTOA on MRL/MpJ mice. (A, B) VEH uninjured and injured MRL/MpJ male mice. There is strong staining through the femoral condyle on both. (C, D) LPS uninjured MRL/MpJ male shows strong staining through the femoral condyle and tibia. LPS injured MRL/MpJ male shows fibrillations, clefts, and lack of staining on areas of the tibia and femoral condyle. (E, F) VEH uninjured MRL/MpJ female shows strong staining through the femoral condyle. VEH injured MRL/MpJ female shows clefts, cartilage thinning, and fibrillations on the femoral and tibial condyle. (G, H) LPS uninjured MRL/MpJ female shows strong cartilage staining through the femoral and tibial condyle. LPS injured MRL/MpJ female shows cartilage thinning and lack of staining on the femoral condyle with cellular infiltration in the anterior tibial condyle. (I) OARSI scoring did not show significant differences when comparing injured and uninjured VEH independent of sex. OARSI scores were significantly higher on LPS injured joints when compared with LPS uninjured and VEH injured independent of sex. There were no significant differences in the sexes when comparing different treatment. *Statistically significantly different than injured joint of the same sex and treatment (p-values < 0.05). **Statistically significantly different than the LPS injured of the same sex (p-values < 0.05).