When I had my DePuy hips, and my chromium and cobalt levels were elevated, my orthopedist said exactly the same thing "It all looks good." Then my thyroid went crazy, my hair started to fall out, I was fatigued... I had the revision surgery, and they had to clean out a lot of damaged tissue in my leg near the implant that was described as looking like "lumpy gray oatmeal" that didn't show on the x-ray. The revision surgeon was amazed at how badly damaged the muscle was. That was over 10 years ago, and I still have a depressed area and a little nerve pain where they removed tissue. My hair grew back, my thyroid normalized, the "new" hips are great, but I was left with a lifelong tremor and rapid heartbeat.
So, if your symptoms worsen, or your heart "gets into the act" you may want to think about revision...