[A case of obturator hernia with overlooked Howship-Romberg sign and treated as sciatica].

We report a case of a patient with incarcerated obturator hernia who presented with right thigh pain. An 88-year-old woman who had experienced right thigh pain for the previous 3 years was given a diagnosis of sciatica at the orthopedic department. In July 2009, she was hospitalized with the chief complaint of appetite loss. The day after admission she experienced increased right thigh pain and lower abdominal pain. Abdominal ultrasonography revealed a keyboard sign. Based on this finding, we diagnosed an ileus, which was alleviated by the insertion of an ileus tube. However, after the removal of the ileus tube, her right thigh pain recurred. Therefore, a diagnosis of hernia was considered. Contrast-enhanced computed tomography revealed an incarcerated bowel in the region between the pectineus muscle and muscle obturator. Laparotomy showed that the ileal part located about 15 cm from the terminal ileum was incarcerated in the right foramen obturatum; therefore, ileal resection and end-to-end anastomosis were performed. After the operation, her intestinal obstruction symptoms and right pain disappeared. If right pain and ileus symptoms of unknown cause occur in elderly persons, obturator hernia should be considered.