For a second time, on Friday, I attempted to place a dexcom sensor on the back of my arm. Sure enough, it failed almost immediately. I removed it and noticed the catheter wasn't attached to the rest of sensor. I feared the worst - that it had become dislodged under my arm. Sure enough, I felt intense pain over the next couple days whenever I flexed my triceps. I contacted dexcom and they assured me I was wrong - I was just imagining it had become loose. I decided to get it x-rayed and sure enough, there was the wire, only split in two pieces. One part 8mm below the surface of my skin and another 16 mm below. Now I have to go see a plastic surgeon :/. Anyways, the true moral of the story is, don't place your dexcom sensor near your muscle! I am almost certain it was the contraction of my muscle that originally tore the catheter out and split it in two.
I'm surprised dexcom told you that. They were recently forced by the FDA to put out an alert than the sensors can oocasionally dislodge and to be aware of the potential problem... Of course, they're also not make to be put into muscle, so it's usually not a big risk from what I understand in the abdomen.
Hope your arm's ok now!