According to House, M.D.’s backstory, what caused Gregory House’s permanent leg injury?

Gregory House’s permanent leg injury was caused by a quadriceps muscle infarction.

In the character’s backstory, a blood clot blocked circulation to the quadriceps muscle in his right thigh. The resulting infarction caused severe tissue damage, and House eventually underwent surgery that left him with chronic pain and a limp.

House uses a cane and relies on pain medication, especially Vicodin, throughout much of the series. His physical disability is not presented as the result of a conventional accident, which is why the exact medical history matters to the character.

The show reveals the history through flashbacks and conversations rather than explaining it all at once. Viewers may incorrectly remember a crash or another trauma because House’s pain and disability are recurring dramatic elements.