Cane-Free!
Item:
No Cane Whatsoever

Episodes: 4 (+?)
House hallucinates or dreams being cane-free in several episodes, including:
  • Babies & Bathwater [S01-E18]
  • No Reason [S02-E-24]
  • House's Head [S04-E15]
  • Wilson's Heart [S04-E16]
He also flashes back to the day of his infarction and the following events in one episode:
  • Three Stories [S01-E21]
He has been genuinely pain- and cane-free for all or part of three episodes:
  • Meaning [S03-E01]
  • Cane and Able [S03-E02]
  • The Softer Side [S05-E16]
Although he was still limping and presumably in at least some pain, he was never seen using a cane in the Season 7 premiere:
  • What Now? [S07-E01]
First Appearance
(part 1):

Meaning
[S03-E01]
In the last episode of the second season, No Reason, House is shot by a former patient. He hallucinates that he is cured of his chronic pain by an experimental Ketamine treatment, and when he awakens briefly on the way to the emergency room, he asks to be given Ketamine.

Cue Season 3. The treatment has worked, and House has spent his two months of recovery time strengthening his leg and exercising. The first time we see him in the new season he is just finishing the eight mile run from his apartment to the hospital.
Last Appearance
(part 1):

Cane and Able
[S03-E02]
After two months of living without pain, it eventually starts creeping back, the first hint being in Meaning. Throughout Cane and Able the pain grows progressively worse. House starts looking for any excuse he can find to sit down, and by the last scene he can barely walk. He gets home and limps to the closet, where Cane #3 has been hibernating.
First Appearance
(part 2):

The Softer Side
[S05-E16]
House has been suspiciously happy lately. He falls asleep in his office and stops breathing, but although he seems to know why it happened, he won't tell anyone. Wilson finally catches him in this alleyway forcing himself to vomit the alcohol he just drank, and the busted House admits that he's been taking methadone, a potentially lethal synthetic opioid ("heroin without the high" as he calls it) that has completely blocked his pain. Wilson starts to lecture him, but House cuts him off by throwing Cane #6 into a dumpster and walking off, turning around just long enough to declare, "My leg doesn't hurt anymore".

Last Appearance
(part 2):

The Softer Side
[S05-E16]
Upon diagnosing his current patient's illness, House discovers that his good mood and willingness to appease the patient's parents was what caused the majority of symptoms in an otherwise healthy child. He blames the methadone that made him too happy to follow his own grumpy instinct. Afraid that his diagnostic skills would be compromised if he continued to take it, he decides to quit the methadone. When Cuddy brings him his next scheduled dose, he drops it in the trash before picking up Aluminum Offset and limping away from her.