Sitting on his couch in Horizon City, Frank Mendez felt his back ache as he watched the Super Bowl with his family last year. He figured the soreness came from the long drive he just made from San Antonio. The confetti fell at the end of a lopsided game and Mendez went to bed thinking a good night of sleep would ease the pain. But the pain worsened with each passing day. He felt like someone was stabbing him on the lower right side of his back. …