In House M.D., what fictional illness is revealed to be the cause of House's leg pain?

In House M.D., House's leg pain is caused by a muscle infarction.

House suffered an infarction in the quadriceps muscle of his right leg after a blood clot blocked circulation. The damaged tissue became necrotic, and surgeons removed part of the muscle. This left him with chronic pain, a limp, and a dependence on a cane. The history is explained through flashbacks and conversations rather than shown as a single uninterrupted origin sequence.

The condition is sometimes confused with a bone injury or a neurological disorder because House walks with difficulty and experiences severe pain. However, the show specifically identifies muscle infarction as the underlying event. House later uses a cane and takes Vicodin, an opioid pain medication. His pain treatment and addiction become recurring parts of the character's story, especially when his use affects his judgment and professional life.