A car accident in which Karen slammed on the brakes to avoid killing a bicyclist led to a chronic knee problem. The pain gradually worsened, until she had to avoid almost any exercise, including walking up the stairs. Knee surgeries only made the condition worse. Despite that, doctors declared the surgery a success (although they chastised her for failing to recover from it), and attributed her problems to a rare bout of post surgical arthritic conditions. Thirteen years later, Karen had to alternate between crutches and a wheelchair.