What condition caused Gregory House to walk with a cane in House M.D.?

Gregory House walks with a cane because of a quadriceps muscle infarction. The condition damaged the muscles in his right thigh before the events of House M.D., leaving him with chronic pain and impaired mobility.

House initially received a misdiagnosis and was treated for a clot. The infarction meant that muscle tissue in his thigh lost its blood supply and died. Although an amputation was considered, surgeon Stacy Warner helped save his leg, and the resulting damage became a permanent part of his character.

The injury explains both House's limp and his dependence on pain medication, particularly Vicodin. It also contributes to his harsh personality and his complicated relationship with Stacy, who is both his former partner and one of the people involved in his treatment.

The cause is sometimes incorrectly described as a broken leg or a generic accident. House's disability is specifically tied to an infarction of the quadriceps muscle, not to a bone fracture or neurological disease.