What caused Dr. Gregory House’s permanent leg injury in House M.D.?

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

Before the main events of House M.D., House suffered an infarction in the quadriceps muscle of his right leg. The condition damaged muscle tissue by cutting off its blood supply, and complications led to the removal of dead tissue. House was left with chronic pain and a pronounced limp.

He later relied on a cane and misused prescription pain medication, particularly Vicodin, to manage the pain. His injury and addiction are major parts of the character’s history and help explain both his physical appearance and many of his personal struggles.

The injury is sometimes simplified as a broken leg, but that is not what the series establishes. House’s limp comes from muscle infarction and its treatment, not from a bone fracture or a sports injury. The detailed backstory is revealed through flashbacks and conversations across the series.