What fictional medical condition causes House’s chronic leg pain in House M.D.?

House’s chronic leg pain is caused by an infarction of the quadriceps muscle in House M.D.

An infarction occurs when a loss of blood supply causes tissue death. In House’s backstory, a vascular event damages muscle in his right thigh, leaving him with permanent pain and impaired movement. He uses a cane and takes medication to manage the condition.

The show presents this injury as a defining event rather than a simple fracture or tendon problem. The exact medical history is revealed gradually, and later episodes revisit how House’s pain, addiction, and decisions are connected. The condition is often loosely described as a leg injury, but the specific diagnosis is quadriceps muscle infarction.