A 67-year-old woman's right knee hurt so badly that her doses of opioid pain medication kept going up. The pain kept getting worse anyway. An X-ray of the knee came back unremarkable.
The problem was not in her knee at all. A CT scan of her abdomen and pelvis revealed an incarcerated obturator hernia, a rare hernia in which tissue pushes through a small opening in the pelvic bone and becomes trapped. After surgeons repaired it, her knee pain improved significantly.
