Figure 1. A schematic representation of the post-traumatic and spontaneous aging models of OA used in this study.

Ten-week old male Tgfa null and heterozygous mice underwent destabilization of medial meniscus (DMM) surgery. Two post-surgical time points were assessed with OARSI scoring: seven and fourteen weeks. Six-month-old Tgfa null and heterozygous mice also underwent DMM surgery and were assessed seven weeks post-surgery. Lastly, Tgfa null and heterozygous mice were housed for eighteen months with no surgical intervention, after which time spontaneous disease progression was assessed with OARSI scoring.