Hi, had three Euflexxa injections into left knee joint, the last of the three one week ago on 6/6/14. That was on a Friday morning, and performed by a different assistant than the previous two, each given a week apart on previous Fridays. Each time injected believe same med / Euflexxa and same amount was used and not sure exactly where precise injection site was located, think a local anesthesia may or may not have been used--very little specific instruction went on. Regarding activity - told 24 hours reduced level, not the recommended 48 hours we have since learned by looking up the procedure online - by Saturday afternoon, expecting to resume a normal activity level, went on a short bike ride to a local store. On the way home, noted a little more stiffness in the joint, but no other obvious problems, just a little more sore than usual, turned in early Saturday night. Tried to have a normal Sunday, by Sunday evening, noted an increased tightness in joint and top lateral shin area - had wife look at and massage leg/knee - she noted a golf-ball size effusion formed behind knee and that the adjacent veins were distended - no swelling in ankles or feet. The next day, nothing had changed, we assumed the fluid accumulation in the knee to be normal reaction to the injections, but reading said allergic reactions can happen and blood clots without obvious symptoms became a concern over the next couple days. The swelling behind the knee disappeared, but a subq mass appeared on the upper lateral shin area whitish and fluidic, my wife questioned if it is an inflammatory response to the hyaloronic product injected? We saw my internist yesterday to rule out embolism with ultrasound/Doppler (report is negative for clot). Question: Can effusion displace the injected gel, can it migrate, what happens to it then? Does it pose a further danger systemically, problems locally? Does strenuous exercise factor in? How is it rid of by the body, metabolized? Exit the body? Can t reach a live person at orthopedic surgeon s office to ask this.