“Three Stories” is the House episode in which House explains his leg injury through three patient cases.
The episode is the 21st episode of House’s first season and uses a distinctive structure. House teaches medical students while presenting three apparently separate cases, gradually revealing that one of the cases is his own medical history.
The story explains that House suffered an infarction in the quadriceps muscle of his right leg. The injury was initially misdiagnosed, and the resulting damage caused chronic pain and the limp for which he uses a cane. The episode also establishes important background for his later dependence on pain medication.
“Three Stories” is frequently cited as one of the series’ landmark episodes. It won the Primetime Emmy Award for Outstanding Writing for a Drama Series. Its title refers to the episode’s three case narratives, not to three seasons or three stages of House’s career.