What fictional medical condition caused Gregory House's permanent leg pain in House M.D.?

A quadriceps infarction caused Gregory House's permanent leg pain in House M.D. The condition damaged muscle tissue in his thigh after a blood clot blocked circulation, leaving him with chronic pain and a limp.

House explains that the infarction affected his right quadriceps muscle. He initially underwent treatment that included surgery, but the damage and resulting pain became a defining part of his life. He uses a cane and relies heavily on pain medication, especially Vicodin, during much of the series.

The backstory is revealed gradually rather than in the pilot. Later episodes show that House's relationship with Stacy Warner and his own medical decisions were connected to the treatment of the leg injury. The story gives context to his mistrust, irritability, and complicated attitude toward disability.

The condition is often misremembered as a broken leg or an injury to a tendon. House's problem is specifically muscle infarction: tissue death caused by inadequate blood supply, not a conventional bone fracture.