Behavioral sensitivity after intra-articular bupivacaine given either at injury or 4 days later. (a) Paw withdrawal threshold (PWT) decreases from baseline on all days (*p<0.027) after injury with immediate intra-articular saline (inj-VEH0h), but PWT after bupivacaine treatment at the time of injury (inj-BP0h) is not different from baseline on all days, as is observed with sham (sham-VEH0h). (b) In contrast, intra-articular bupivacaine given at 4 days after injury (inj-BPd4) has no effect on PWT, with decreased PWT compared to baseline on all days (*p<0.003), similar to the injury with a saline vehicle injection (inj-VEHd4) (^p<0.0001).